CA2639307A1 - Method for at least partially compensating for errors in ink dot placement due to erroneous rotational displacement - Google Patents

Method for at least partially compensating for errors in ink dot placement due to erroneous rotational displacement Download PDF

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Publication number
CA2639307A1
CA2639307A1 CA002639307A CA2639307A CA2639307A1 CA 2639307 A1 CA2639307 A1 CA 2639307A1 CA 002639307 A CA002639307 A CA 002639307A CA 2639307 A CA2639307 A CA 2639307A CA 2639307 A1 CA2639307 A1 CA 2639307A1
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CA
Canada
Prior art keywords
nozzles
printhead
printhead module
row
data
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
CA002639307A
Other languages
French (fr)
Inventor
Simon Robert Walmsley
Kia Silverbrook
Mark Jackson Pulver
John Robert Sheahan
Richard Thomas Plunkett
Michael John Webb
Benjamin David Morphett
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Silverbrook Research Pty Ltd
Original Assignee
Simon Robert Walmsley
Kia Silverbrook
Mark Jackson Pulver
John Robert Sheahan
Richard Thomas Plunkett
Michael John Webb
Benjamin David Morphett
Silverbrook Research Pty Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Simon Robert Walmsley, Kia Silverbrook, Mark Jackson Pulver, John Robert Sheahan, Richard Thomas Plunkett, Michael John Webb, Benjamin David Morphett, Silverbrook Research Pty Ltd filed Critical Simon Robert Walmsley
Priority to CA2716065A priority Critical patent/CA2716065A1/en
Priority to CA2716810A priority patent/CA2716810A1/en
Priority to CA2716778A priority patent/CA2716778A1/en
Priority to CA2716853A priority patent/CA2716853A1/en
Priority to CA002639307A priority patent/CA2639307A1/en
Priority claimed from CA002567724A external-priority patent/CA2567724A1/en
Publication of CA2639307A1 publication Critical patent/CA2639307A1/en
Abandoned legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01—Ink jet
    • B41J2/21—Ink jet for multi-colour printing
    • B41J2/2132—Print quality control characterised by dot disposition, e.g. for reducing white stripes or banding
    • B41J2/2135—Alignment of dots
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J29/00—Details of, or accessories for, typewriters or selective printing mechanisms not otherwise provided for
    • B41J29/38—Drives, motors, controls or automatic cut-off devices for the entire printing mechanism
    • B41J29/393—Devices for controlling or analysing the entire machine ; Controlling or analysing mechanical parameters involving printing of test patterns
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K15/00—Arrangements for producing a permanent visual presentation of the output data, e.g. computer output printers
    • G06K15/02—Arrangements for producing a permanent visual presentation of the output data, e.g. computer output printers using printers
    • G06K15/10—Arrangements for producing a permanent visual presentation of the output data, e.g. computer output printers using printers by matrix printers
    • G06K15/102—Arrangements for producing a permanent visual presentation of the output data, e.g. computer output printers using printers by matrix printers using ink jet print heads

Abstract

A method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier, the nozzles being disposed on the printhead module, the method comprising the steps of: (a) determining the rotational displacement; (b) determining at least one correction factor that at least partially compensates for the ink dot displacement; and (c) using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

Description

DEMANDES OU BREVETS VOLUMINEUX
LA PRESENTE PARTIE DE CETTE DEMANDE OU CE BREVETS
COMPREND PLUS D'UN TOME.

CECI EST LE TOME DE _3 NOTE: Pour les tomes additionels, veillez contacter le Bureau Canadien des Brevets.

JUMBO APPLICATIONS / PATENTS

THIS SECTION OF THE APPLICATION / PATENT CONTAINS MORE
THAN ONE VOLUME.

NOTE: For additional volumes please contact the Canadian Patent Office.

Method for at least partially compensating for errors in ink dot placement due to erroneous rotational displacement FIELD OF THE INVENTTON

The present invention relates to a method of compensating for errors in ink dot placement due to erroneous rotational displacement of a printhead or printhead module.

The invention has primarily been developed for use in a pagewidth inkjet printer comprising a printer controller and a printhead having one or more printhead modules, and will be described with reference to this example.
However, it will be appreciated that the invention is not limited to any particular type of printing technology, and is not limited to use in, for example, pagewidth and inkjet printing.

CROSS-REFERENCES
Various methods, systems and apparatus relating to the present invention are disclosed in the following co-pending applications filed by the applicant or assignee of the present invention. The disclosures of all of these co-pending applications are incorporated herein by cross-reference.

10/727,181 10/727,162 10/727,163 10/727,245 PEA05US
10/727,233 10/727,280 10/72 7,15 7 10/727,178 10/72,210 PEA11US 10/727,238 10/727,251 10/727,159 10/727,180 PEAI6US PEA17US PEA18US 10/727,164 10/727,161 10/727,198 10/727,158 10/754,536 10/754,938 10/727,227 10/727,160 09/575,108 10/727,162 09/575,110 09/607,985 6,398,332 6,394,573 6,622,923 10/173,739 10/189,459 10/713,083 10/713,091 ZG 164US 10/713,077 10/713,081 10/713,080 10/667,342 10/664,941 10/664,93 9 10/664, 9 3 8 10/665,069 09/112,763 09/112,762 09/112,737 09/112,761 09/113,223 09/505,951 09/505,147 09/505.952 09/517,539 09/517,384 09/516,869 09/517,608 09/517,380 09/516,874 09/517,541 10/636,263 10/636,283 ZE028US ZE029US

ZE030US 10/407,212 10/407,207 10/683,064 10/683,041 Some applications have been listed by their docket numbers, these will be replaced when application numbers are known.

BACKGROUND
When a printhead module is being mounted to a carrier, there is the possibility that the position of the printhead will be rotationally erroneous. Stich errors arise due to the tolerances in the assembly process, for example.

In cases where the printhead module is short, and particularly where it is the only module in the printhead, minor rotational errors may be acceptable. However, in the case of relatively long printheads, the amount of error introduced to dot positions due to the erroneous rotational position of the printhead module relative to the carrier may reach noticeable, and therefore unacceptable (or at least undesirable) levels.

The problem is exacerbated when multiple printhead modules are laid end to end to form a printhead, such as a pagewidth printhead, due to the fact that some forms of rotational error will cause discontinuities between rows of dots printed by adjacent modules. In general, these discontinuities are more visible and objectionable than mere consistent skew across a single printhead module.

It would be useful to provide a method and apparatus for at least partially compensating for errors in ink dot placement due to erroneous rotational displacement of a printhead module relative to a carrier.
SUMMARY OF THE INVENTION

In a first aspect the present invention provides a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier, the nozzles being disposed on the printhead module, the method comprising the steps of:

(a) determining the rotational displacement;

(b) determining at least one correction factor that at least partially compensates for the ink dot displacement;
and (c) using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

Optionally, step (c) includes altering a timing of a fire signal to at least one of the nozzles on the basis of the correction factor, thereby to effect the at least partial compensation.

Optionally, the nozzles are disposed in a plurality of rows, and step (c) includes reallocating at least one of the ink dots from at least one original print line to at least one alternate print line, thereby to effect the at least partial compensation.

Optionally, step (c) further includes the step of altering a timing of fire signals to at least one of the nozzles on the basis of the correction factor, thereby to effect the at least partial compensation.

Optionally, the altered fire signals are supplied to both reallocated ink dots and non-reallocated ink dots.

Optionally, the correction factor is stored in a memory associated with the printhead Optionally, the memory is mounted with the printhead, the printhead being mounted on the print engine.
Optionally, the rotational displacement is roll.

Optionally, the rotational displacement is yaw.

Optionally, the printhead module being one of a plurality of printhead modules mounted on a canier to fonn a printhead and the error in ink dot placement being an error relative to ink dots output by one or more of the other printhead modules Optionally, the printer is a pagewidth printer.
Optionally, the printer is a pagewidth printer.

Optionally, the present invention provides a printer controller programmed and configured to implement the method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier, the nozzles being disposed on the printhead module, the method comprising the steps of:

(a) determining the rotational displacement;

(b) determining at least one correction factor that at least partially compensates for the ink dot displacement;
and (c) using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

Optionally, the method including expelling ink from a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally, the method including expelling ink from a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:

(a) providing a fire signal to nozzles at a first and nth position in each set of nozzles;
(b) providing a fire signal to the next inward pair of nozzles in each set;

(c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and (d) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

Optionally, the method including manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.
Optionally, the method being perfon:ned in conjunction with a printhead module including:

at least one row of print nozzles;

at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, 5 wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.
Optionally, the method being performed in a printer comprising:

a printhead comprising at least a first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

Optionally, the method being performed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.
Optionally, the method being performed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

Optionally, the method being perfonned in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the fust printer controller.

Optionally, the method being perfonmed in conjunction with a printer controller for supplying dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:

access a correcrion factor associated with the at least one printhead module;

detennine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

Optionally, the method being performed in conjunction with a printer controller for supplying dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

Optionally, the method being performed in conjunction with a printer controller for controlling a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective con-esponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

Optionally, the method being performed in conjunction with a printer controller for outputting to a printhead module:

dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;

the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.

Optionally, the method being performed in conjunction with a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally, the method being performed in conjunction with a printer controller for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:

a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;

wherein the printer controller is selectively configurable to supply dot data for the first and second modes.
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Optionally, the method being performed in conjunction with a printer controller for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.
Optionally, the method being used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:

(a) providing a fire signal to nozzles at a first and nth position in each set of nozzles;
(b) providing a fire signal to the next inward pair of nozzles in each set;

(c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and (d) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

Optionally, the method being used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally, the method being performed in conjunction with a printer controller for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

Optionally, the method being performed in conjunction with a printer controller for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.
Optionally, the method being performed in conjunction with a printer controller for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead, wherein each of the serial outputs is configured to supply dot data for at least two channels of the at least one printhead.

Optionally, the method being performed in conjunction with a printhead module including:
at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally, the method being performed in conjunction with a printhead capable of printing a maximum of n of channels of print data, the printhead being configurable into:

a first mode, in which the printhead is configured to receive print data for a first number of the channels;
and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

Optionally, the method being performed in conjunction with a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is deternuned by its geometric shape in plan.

Optionally, the method being performed in conjunction with a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally, the method being performed in conjunction with a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:

in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

5 Optionally, the method being performed in conjunction with a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.
Optionally, the method being performed in conjunction with a printhead module including at least one row of 10 printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally, the method being performed in conjunction with a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

Optionally, the met hod being performed in conjunction with a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

Optionally, the method being performed in conjunction with a printer controller for providing data to a printhead module that includes:

at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.
Optionally, the method being performed in conjunction with a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.
Optionally, the method being performed in conjunction with a printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

In a second aspect the present invention provides a method of expelling ink from a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.
Optionally the nozzle at each given position within the set is fired simultaneously with the nozzles in the other sets at respective corresponding positions.

Optionally the printhead module includes a plurality of the rows of nozzles, the method including sequentially repeating the for each of the rows of nozzles.

Optionally the rows are disposed in pairs.

Optionally the rows in each pair of rows are offset relative to each other.
Optionally each pair of rows is configured to print the same color ink.

Optionally each pair of rows is connected to a common ink source.
Optionally the sets of nozzles are adjacent each other.

Optionally the sets of nozzles are separated by an intermediate nozzle, the intermediate nozzle being fired either prior to the nozzle at position 1 in each set, or following the nozzle at position n.

Optionally the method includes the step of providing the fire sequence to the printhead module from a printer controller, the fire signals being based on the fire sequence.

Optionally the fire sequence is loaded into a shift register in the printhead module.

Optionally the method at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to enoneous rotational displacement of a printhead module relative to a carrier, the nozzles being disposed on the printhead module, the method comprising the steps of:

(a) determining the rotational displacement;

(b) detenmining at least one correction factor that at least partially compensates for the ink dot displacement;
and (c) using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

Optionally the method includes expelling ink from a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:

(a) providing a fire signal to nozzles at a first and nth position in each set of nozzles;
(b) providing a fire signal to the next inward pair of nozzles in each set;

(c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and (d) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.
Optionally the method includes manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.

Optionally, the method being performed in conjunction with a printhead module including:
at least one row of print nozzles;

at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

Optionally, the method being performed in a printer comprising:

a printhead comprising at least a first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

Optionally, the method being performed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

Optionally, the method being performed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

Optionally, the method being performed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the fust printer controller.

Optionally, the method being performed in conjunction with a printer controller for supplying dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:

access a con=ection factor associated with the at least one printhead module;

determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being detennined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

Optionally, the method being performed in conjunction with a printer controller for supplying dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thenmal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

Optionally, the method being performed in conjunction with a printer controller for controlling a piinthead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each 5 subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of ftring of the nozzles.

Optionally, the method being performed in conjunction with a printer controller for outputting to a printhead module:

10 dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;

the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.

Optionally, the method being performed in conjunction with a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally, the method being performed in conjunction with a printer controller for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:

a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;

wherein the printer controller is selectively configurable to supply dot data for the first and second modes.
Optionally, the method being performed in conjunction with a printer controller for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally, the method being used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:

(a) providing a fire signal to nozzles at a first and nth position in each set of nozzles;
(b) providing a fire signal to the next inward pair of nozzles in each set;

(c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and (d) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

Optionally, the method being used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally, the method being performed in conjunction with a printer controller for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

Optionally, the method being performed in conjunction with a printer controller for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

Optionally, the method being performed in conjunction with a printer controller for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead, wherein each of the serial outputs is configured to supply dot data for at least two channels of the at least one printhead.

Optionally, the method being performed in conjunction with a printhead module including:
at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally, the method being performed in conjunction with a printhead capable of printing a maximum of n of channels of print data, the printhead being configurable into:

a fust mode, in which the printhead is configured to receive print data for a first number of the channels;
and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

Optionally, the method being performed in conjunction with a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally, the method being performed in conjunction with a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally, the method being performed in conjunction with a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:

in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

Optionally, the method being perfonned in conjunction with a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

Optionally, the method being performed in conjunction with a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row ponfion including a component in a direction normal to that of a pagewidth to be printed.

Optionally, the method being performed in conjunction with a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least fust and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.
Optionally, the method being performed in conjunction with a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurabie such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

Optionally, the method being performed in conjunction with a printer controller for providing data to a printhead module that includes:

at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally, the method being performed in conjunction with a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of therrnal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

Optionally, the method being performed in conjunction with a printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

Optionally the printhead module includes a plurality of the rows, the method including firing each nozzle in each row simultaneously with the nozzle or nozzles at the same position in the other rows.

Optionally the method includes a plurality of pairs of the rows, each pair of rows including an odd row and an even row, the odd and even rows in each pair being offset from each other in both x and y directions relative to an intended direction of print media movement relative to the printhead, the method including causing firing of at least a plurality of the odd rows prior to firing any of the even rows, or vice versa.

Optionally all the odd rows are fired before any of the even rows are fired, or vice versa.

Optionally the odd rows, or the even rows, or both, are fired in a predetermined order.

Optionally the predetermined order is selectable from a plurality of predetermined available orders.
Optionally the predetermined order is sequential.

Optionally the predetermined order can commence at any of a plurality of the rows.

In a third aspect the present invention provides a method of expelling ink from a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel 5 ink in response to a fire signal, the method comprising the steps of:

(a) providing a fire signal to nozzles at a fust and nth position in each set of nozzles;
(b) providing a fire signal to the next inward pair of nozzles in each set;

(c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and (d) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set 10 have been fired, and then firing the central nozzle.

Optionally the printhead module includes a plurality of the rows of nozzles, the method including sequentially repeating steps (a) to (d) for each of the rows of nozzles.
15 Optionally the rows are disposed in pairs.

Optionally the rows in each pair of rows are offset relative to each other.
Optionally each pair of rows is configured to print the same color ink.

Optionally each pair of rows is connected to a common ink source.
Optionally the sets of nozzles are adjacent each other.

Optionally the sets of nozzles are separated by an intermediate nozzle, the intermediate nozzle being fired either prior to the nozzle at position 1 in each set, or following the nozzle at position n.

In a second aspect the present invention provides a method of expelling ink from a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the nozzle at each given position within the set is fired simultaneously with the nozzles in the other sets at respective corresponding positions.

Optionally, the method at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier, the nozzles being disposed on the printhead module, the method comprising the steps of:

(a) determining the rotational displacement;

(b) determining at least one correction factor that at least partially compensates for the ink dot displacement;
and (c) using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

Optionally, the method including expelling ink from a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally, the method including manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.

Optionally, the method being performed in conjunction with a printhead module including:
at least one row of print nozzles;

at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

Optionally, the method being performed in a printer comprising:

a printhead comprising at least a first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

Optionally, the method being performed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second pcinthead module, wherein the printhead modules are configured such that no dot data passes between them.
Optionally, the method being performed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

Optionally, the method being performed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the fust printer controller.

Optionally, the method being performed in conjunction with a printer controller for supplying dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:

access a correction factor associated with the at least one printhead module;

deterniine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being detennined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

Optionally, the method being performed in conjunction with a printer controller for supplying dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

Optionally, the method being performed in conjunction with a printer controller for controlling a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

Optionally, the method being performed in conjunction with a printer controller for outputting to a printhead module:

dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;

the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.

Optionally, the method being performed in conjunction with a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally, the method being performed in conjunction with a printer controller for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:

a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;

wherein the printer controller is selectively configurable to supply dot data for the first and second modes.
Optionally, the method being performed in conjunction with a printer controller for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally, the method being used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:

(a) providing a fire signal to nozzles at a fust and nth position in each set of nozzles;
(b) providing a fire signal to the next inward pair of nozzles in each set;

(c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and (d) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

Optionally, the method being used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, 5 the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally, the method being performed in conjunction with a printer controller for supplying dot data to a 10 printhead module comprising at least fnst and second rows configured to print ink of a similar type or color, at least some nozzles in the fnst row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from 15 the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

Optionally, the method being perfonned in conjunction with a printer controller for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows 20 comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

Optionally, the method being performed in conjunction with a printer controller for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead, wherein each of the serial outputs is configured to supply dot data for at least two channels of the at least one printhead.

Optionally, the method being performed in conjunction with a printhead module including:
at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally, the method being performed in conjunction with a printhead capable of ptinting a maximum of n of channels of print data, the printhead being configurable into:

a first mode, in which the printhead is configured to receive print data for a first number of the channels;
and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

Optionally, the method being performed in conjunction with a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally, the method being performed in conjunction with a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), _.. , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally, the method being performed in conjunction with a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:

in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

Optionally, the method being performed in conjunction with a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

Optionally, the method being performed in conjunction with a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally, the method being performed in conjunction with a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.
Optionally, the method being performed in conjunction with a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

Optionally, the method being performed in conjunction with a printer controller for providing data to a printhead module that includes:

at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally, the method being performed in conjunction with a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

Optionally, the method being performed in conjunction with a printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

Optionally the printhead module includes a plurality of the rows, the method including firing each nozzle in each row simultaneously with the nozzle or nozzles at the same position in the other rows.

Optionally the printhead module includes a plurality of the rows, the method including firing each nozzle in each row simultaneously with the nozzle or nozzles at the same position in the other rows.

Optionally the method including a plurality of pairs of the rows, each pair of rows including an odd row and an even row, the odd and even rows in each pair being offset from each other in both x and y directions relative to an intended direction of print media movement relative to the printhead, the method including causing firing of at least a plurality of the odd rows prior to firing any of the even rows, or vice versa.
Optionally all the odd rows are fired before any of the even rows are fired, or vice versa.
Optionally the odd rows, or the even rows, or both, are fired in a predetermined order.

Optionally the predetermined order is selectable from a plurality of predetenmined available orders.
Optionally the predetennined order is sequential.

Optionally the predetennined order can commence at any of a plurality of the rows.

In a fourth aspect the present invention provides method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.

In a second aspect the present invention provides a method of manufacturing a plurality of pagewidth printheads, the method comprising the steps of:

manufacturing a plurality of printhead modules in accordance with claim 1; and assembling pairs of at least some of the printhead modules to form pagewidth printheads, wherein each of the printhead modules in each pagewidth printhead is shorter than the pagewidth.

Optionally the printhead modules of at least one of the pagewidth printheads are of relatively different lengths.
Optionally the printhead modules of at least one of the pagewidth printheads are of the same length.
Optionally the printhead modules of at least one of the pagewidth printheads are of relatively different lengths, and the printhead modules of at least another of the pagewidth printheads are of the same length.

Optionally at least some of the printhead modules are larger than a reticle step used in laying out those printhead modules.

Optionally the method includes the step of laying out a plurality of left-handed and right-handed printhead modules.

Optionally the method includes the step of laying out a plurality of different lengths of left-handed and right-handed printhead modules.

Optionally, the method at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier, the nozzles being disposed on the printhead module, the method comprising the steps of (a) detenmining the rotational displacement;

(b) detenn-~ining at least one correction factor that at least partially compensates for the ink dot displacement;
and (c) using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

Optionally, the method including expelling ink from a printhead module including at least one row that comprises 5 a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at.or adjacent the centre of the set of nozzles.

10 Optionally, the method including expelling ink from a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:

(a) providing a fire signal to nozzles at a first and nth position in each set of nozzles;
(b) providing a fire signal to the next inward pair of nozzles in each set;

15 (c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and (d) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

Optionally, the method being performed in conjunction with a printhead module including:
20 at least one row of print nozzles;

at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.
Optionally, the method being performed in a printer comprising:

25 a printhead comprising at least a first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

Optionally, the method being performed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

Optionally, the method being performed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

Optionally, the method being performed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

Optionally, the method being performed in conjunction with a printer controller for supplying dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:

access a correction factor associated with the at least one printhead module;

detemune an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being detemlined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

Optionally, the method being performed in conjunction with a printer controller for supplying dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

Optionally, the method being performed in conjunction with a printer controller for controlling a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

Optionally, the method being performed in conjunction with a printer controller for outputting to a printhead module:

dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;

the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.
Optionally, the method being performed in conjunction with a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally, the method being performed in conjunction with a printer controller for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:

a first mode, in which the printhead module is configured to receive data for a fust number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;

wherein the printer controller is selectively configucable to supply dot data for the first and second modes.

Optionally, the method being performed in conjunction with a printer controller for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally, the method being used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:

(a) providing a fire signal to nozzles at a first and nth position in each set of nozzles;
(b) providing a fire signal to the next inward pair of nozzles in each set;

(c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and (d) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

Optionally, the method being used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally, the method being perfonned in conjunction with a printer controller for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective con-esponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

Optionally, the method being performed in conjunction with a printer controller for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

Optionally, the method being performed in conjunction with a printer controller for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead, wherein each of the serial outputs is configured to supply dot data for at least two channels of the at least one printhead.

Optionally, the method being performed in conjunction with a printhead module including:
at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally, the method being performed in conjunction with a printhead capable of printing a maximum of n of channels of print data, the printhead being configurable into:

a fust mode, in which the printhead is configured to receive print data for a first number of the channels;
and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

Optionally, the method being performed in conjunction with a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally, the method being performed in conjunction with a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle 10 position x is at or adjacent the centre of the set of nozzles.

Optionally 1, the method being performed in conjunction with a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in 15 each set of nozzles, and then each next inward pair of nozzles in each set, until:

in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

20 Optionally, the method being performed in conjunction with a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.
Optionally, the method being perfonmed in conjunction with a printhead module including at least one row of 25 printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally, the method being performed in conjunction with a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being 30 grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.
Optionally, the method being performed in conjunction with a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective con-esponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

Optionally, the method being performed in conjunction with a printer controller for providing data to a printhead module that includes:

at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally, the method being performed in conjunction with a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.
Optionally, the method being performed in conjunction with a printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

In a fifth aspect the present invention provides a printhead module including:
at least one row of print nozzles;

at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

Optionally, there is a one to one correspondence between the nozzles and elements of the two shift registers.
Optionally, each of the shift registers supplies dot data to about half of the nozzles.

Optionally the printhead module includes at least one pair of rows of the nozzles, the rows in each pair being offset with respect to each other by half the intra-row nozzle spacing.

Optionally, each of the at least two shift registers supplies dot data to at least some of the nozzles in at least one pair of rows.

Optionally the present invention provides a printhead comprising a plurality of printhead modules including:
at least one row of print nozzles;

at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.
Optionally, the printhead is a pagewidth printhead.

Optionally the printhead module is configured to receive dot data to which a method of at least partially compensating for eirors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier has been applied, the nozzles being disposed on the printhead module, the method comprising the steps of:

(a) determining the rotational displacement;

(b) determining at least one correction factor that at least partially compensates for the ink dot displacement;
and (c) using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

Optionally the printhead module is configured to receive dot data to which a method of expelling ink has been applied, the method being applied to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printhead module is configured to receive dot data to which a method of expelling ink has been applied, the method being applied to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:

(a) providing a fire signal to nozzles at a first and nth position in each set of nozzles;
(b) providing a fire signal to the next inward pair of nozzles in each set;

(c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and (d) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

Optionally the printhead module having been manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth pnntheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.

Optionally the printhead module including:
at least one row of print nozzles;

at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

Optionally the printhead module installed in a printer comprising:

a printhead comprising at least the first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

Optionally the printhead module installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

Optionally the printhead module installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

Optionally the printhead module installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region,.
wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the fust printer controper.

Optionally the printhead module is in communication with a printer controller for supplying dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:

access a correction factor associated with the at least one printhead module;

determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and 5 supply the dot data to the printhead module.

Optionally the printhead module is in communication with a printer controller for supplying dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least 10 one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

Optionally the printhead module is in communication with a printer controller for controlling a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows 15 of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each 20 subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

Optionally the printhead module is in conununication with a printer controller for outputting to a printhead module:

25 dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;

the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.

Optionally the printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally the printhead module is in communication with a printer controller for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:

a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number, wherein the printer controller is selectively configurable to supply dot data for the first and second modes.
Optionally the printhead module is in conununication with a printer controller for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is detennined by its geometric shape in plan.

Optionally the printhead module is used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:

(a) a fire signal is provided to nozzles at a first and nth position in each set of nozzles;
(b) a fire signal is provided to the next inward pair of nozzles in each set;

(c) in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired;
and (d) in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

Optionally the printhead module is used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printhead module is in communication with a printer controller for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the fiust row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

Optionally the printhead module is in communication with a printer controller for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

Optionally the printhead module is in communication with a printer controller for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

Optionally the printhead module including:
at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally the printhead module being capable of printing a maximum of n of channels of print data, the printhead being configurable into:

a fust mode, in which the printhead is configured to receive print data for a first number of the channels;
and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

Optionally a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:

in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

Optionally a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

Optional a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

Optionally a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

Optionally a printhead module is in communication with a printer controller for providing data to a printhead module that includes:

at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

Optionally a printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the fust row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

In a sixth aspect the present invention provides printer comprising:

a printhead comprising at least a first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input 5 of the printhead.

Optionally the printer including at least one synchronization means between the first and second printer controllers for synchronizing the supply of dot by the printer controllers.

10 Optionally the printer configured such that the first and second printer controllers sequentially provide the dot data to the common input.

Optionally the printer further including a second printhead module, the printer being configured such that: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the 15 second printer controller outputs dot data only to the second printhead module.

Optionally the printhead modules are configured such that no dot data passes between them.

Optionally each of the printer controllers is configurable to supply the dot data to printhead modules of a plurality 20 of different lengths.

Optionally the printhead is a pagewidth printhead.

In a further aspect the present invention provides a print engine comprising:
25 a carrier;

a printhead comprising at least a first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input 30 of the printhead.

Optionally the printer including at least one synchronization means between the first and second printer controllers for synchronizing the supply of dot by the printer controllers.

Optionally the printer configured such that the first and second printer controllers alternately provide the dot data to the common input.

Optionally the printer further including a second printhead module, the printer being configured such that: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second piinter controller outputs dot data only to the second printhead module.

Optionally the printhead modules are configured such that no dot data passes between them.

Optionally each of the printer controllers is configurable to supply the dot data to printhead modules of a plurality of different lengths.

Optionally the printhead is a pagewidth printhead.

In a further aspect the present invention provides a printer comprising:

a printhead comprising at least a first elongate printhead module, the at least one printhead module including at least first and second rows of print nozzles for expelling ink;
and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to the pzinthead to supply data for the first and second rows of nozzles, respectively.

Optionally the printer including at least one synchronization means between the first and second printer controllers for synchronizing the supply of dot by the printer controllers.

Optionally the printhead modules are configured such that no dot data passes between them.

Optionally the printhead is a pagewidth printhead.

Optionally the printer is for implementing a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier, the nozzles being disposed on the printhead module, the method comprising the steps of:

(a) determining the rotational displacement;

(b) determining at least one correction factor that at least partially compensates for the ink dot displacement;
and (c) using the con-ection factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

Optionally the printer is for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printer is for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:

(a) providing a fire signal to nozzles at a first and nth position in each set of nozzles;
(b) providing a fire signal to the next inward pair of nozzles in each set;

(c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and (d) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

Optionally the printer is manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.

Optionally the printer including a printhead module including:

at least one row of print nozzles;

at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

Optionally the printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

Optionally the printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the fust printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

Optionally the printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the fust printer controller.

Optionally the printer including at least one printhead module, configured for at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:

access a correction factor associated with the at least one printhead module;

determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby' to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

Optionally the printer including a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

Optionally the printer controls a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

Optionally the printer including a printer controller for sending to a printhead:
dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;

the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.

Optionally the printer including a printer controller for supplying data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

5 Optionally the printer including a printer controller for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:

a first mode, in which the printhead module is configured to receive data for a first number of the channels; and 10 a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number, wherein the printer controller is selectively configurable to supply dot data for the first and second modes.
Optionally the printer including a ptinter controller for supplying data to a printhead comprising a plurality of 15 printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape.in plan.
Optionally the printer including a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, 20 each of the nozzles being configured to expel ink in response to a fire signal, such that:

(a) a fire signal is provided to nozzles at a fust and nth position in each set of nozzles;
(b) a fire signal is provided to the next inward pair of nozzles in each set;

(c) in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired;
and 25 (d) in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

Optionally the printer including a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent 30 nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printer including a printer controller for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

Optionally the printer including a printer controller for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least fust and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

Optionally the printer including a printer controller for receiving fust data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

Optionally the printer including a printer controller for supplying data to a printhead module including:
at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally the printer including a printer controller for supplying data to a printhead capable of printing a maximum of n of channels of print data, the printhead being configurable into:

a first mode, in which the printhead is configured to receive print data for a first number of the channels;
and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

Optionally the printer including a printer controller for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally the printer including a printer controller for supplying data to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printer including a printer controller for supplying data to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:

in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

Optionally the printer including a printer controller for supplying data to a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.
Optionally the printer including a printer controller for supplying data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally the printer including a printer controller for supplying data to a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.
Optionally the printer including a printer controller for supplying data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

Optionally the printer including a printer controller for providing data to a printhead module that includes:
at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally the printer including a printer controller for supplying data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thenmal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

Optionally the printer including a printer controller for supplying data to a printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

In a seventh aspect the present invention provides a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

Optionally the printer includes at least one synchronization means between the first and second printer controllers for synchronizing the supply of dot by the printer controllers.

Optionally each of the printer controllers is configurable to supply the dot data to a printhead module of arbitrary length.

Optionally the first and second printhead modules are equal in length.
Optionally the first and second ptinthead modules are unequal in length.
Optionally the printhead is a pagewidth printhead.

In a further aspect the present invention provides a print engine comprising:
a carrier;

a printhead comprising first and second elongate printhead modules, the printhead modules being mounted parallel to each other end to end on the carrier on either side of a join region;

at least first and second printer controllers mounted on the carrier and being configured to receive print data and process the print data to output dot data to the printhead, wherein the fust printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

Optionally the print engine includes at least one synchronization means between the first and second printer controllers for synchronizing the supply of dot by the printer controllers.

Optionally each of the printer controllers is configurable to supply the dot data to a printhead module of arbitrary 5 length.

Optionally the first and second printhead modules are equal in length.
Optionally the first and second printhead modules are unequal in length.

Optionally the printhead is a pagewidth printhead.

Optionally the printer is for implementing a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier, the nozzles being disposed on the printhead module, the method comprising the steps of:

(a) determining the rotational displacement;

(b) determining at least one correction factor that at least partially compensates for the ink dot displacement;
and (c) using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

Optionally the printer is for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire. signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printer is for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:

(a) providing a fire signal to nozzles at a first and nth position in each set of nozzles;

(b) providing a fire signal to the next inward pair of nozzles in each set (c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and (d) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been ftred, and then firing the central nozzle.

Optionally the printer is manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.

Optionally the printer includes a printhead module including:
at least one row of print nozzles;

at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

Optionally the printer comprises:

a printhead comprising at least a first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

Optionally the printer comprises:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

Optionally the printer comprises:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the fust printer controller.

Optionally the printer comprises at least one printhead module, configured for at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:

access a cotrection factor associated with the at least one printhead module;

determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being detennined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

Optionally the printer comprises a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer being configured to modify operation of at least some of the nozzles in response to the temperature rising above a fust threshold.

Optionally the printer controls a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

Optionally the printer includes a printer controller for sending to a printhead:

dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;

the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.

Optionally the printer includes a printer controller for supplying data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally the printer includes a printer controller for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:

a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;

wherein the printer controller is selectively configurable to supply dot data for the first and second modes.

Optionally the printer includes a printer controller for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is detennined by its geometric shape in plan.

Optionally the printer includes a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:

(a) a fire signal is provided to nozzles at a first and nth position in each set of nozzles;
(b) a fire signal is provided to the next inward pair of nozzles in each set;

(c) in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired;
and (d) in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

Optionally the printer includes a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printer includes a printer controller for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the fust pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

Optionally the printer includes a printer controller for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

Optionally the printer includes a printer controller for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

Optionally the printer includes a printer controller for supplying data to a printhead module including:
at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

5 Optionally the printer includes a printer controller for supplying data to a printhead capable of printing a maximum of n of channels of print data, the printhead being configurable into:

a fust mode, in which the printhead is configured to receive print data for a first number of the channels;
and a second mode, in which the printhead is configured to receive print data for a second number of the 10 channels, wherein the first number is greater than the second number.

Optionally the printer includes a printer controller for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally the printer includes a printer controller for supplying data to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printer includes a printer controller for supplying data to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:
in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

Optionally the printer includes a printer controller for supplying data to a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

Optionally the printer includes a printer controller for supplying data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally the printer includes a printer controller for supplying data to a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.
Optionally the printer includes a printer controller for supplying data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the fust row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the fust and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

Optionally the printer includes a printer controller for providing data to a printhead module that includes:
at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied'from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally the printer includes a printer controller for supplying data to a printhead module having a plurality of nozzles for expelling inlc, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

Optionally the printer includes a print.er controller for supplying data to a printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the fust row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.
In an eighth aspect the present invention provides a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

Optionally the printhead modules are configured such that no dot data passes between them.

Optionally the printer includes at least one synchronization means between the first and second printer controllers for synchronizing the supply of dot data by the printer controllers.

Optionally each of the printer controllers is configurable to supply the dot data to printhead modules of a plurality of different lengths.

Optionally the printhead is a pagewidth printhead.

In a further aspect the present invention provides a print engine comprising:
a carrier;

a printhead comprising first and second elongate printhead modules, the printhead modules being mounted parallel to each other end to end on the carrier on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers mounted on the carrier and being configuned to receive print data and process the print data to output dot data to the printhead, wherein:
the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

Optionally the printhead modules are configured such that no dot data passes between them.

Optionally the print engine includes at least one synchronization means between the first and second printer controllers for synchronizing the supply of dot by the printer controllers.

Optionally each of the printer controllers is configurable to supply the dot data to printhead modules of a plurality of different lengths.

Optionally the printhead is a pagewidth printhead.

Optionally the printer is for implementing a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier, the nozzles being disposed on the printhead module, the method comprising the steps of (a) determining the rotational displacement;

(b) determining at least one correction factor that at least partially compensates for the ink dot displacement;
and (c) using the correction factor to alter the output of the ink dots to at Ieast partially compensate for the rotational displacement.

Optionally the printer is for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printer is for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:

(a) providing a fire signal to nozzles at a first and nth position in each set of nozzles;
(b) providing a fire signal to the next inward pair of nozzles in each set;

(c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and (d) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

Optionally the printer is manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.

Optionally the printer includes a printhead module including:
at least one row of print nozzles;

at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

Optionally the printer includes:

a printhead comprising at least a first elongate printhead module, the at least one printhead module including at least one row of ptint nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

Optionally the printer includes:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

Optionally the printer includes:

5 a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead 10 module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

Optionally the printer includes at least one printhead module, configured for at least partially compensating for 15 errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:

access a correction factor associated with the at least one printhead module;

determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at 20 least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

Optionally the printer includes a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a 25 temperature at or adjacent at least one of the nozzles, the printer being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

Optionally the printer controls a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a 30 printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and sccond fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

Optionally the printer includes a printer controller for sending to a printhead:
dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;

the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.

Optionally the printer includes a printer controller for supplying data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally the printer includes a printer controller for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:

a fust mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the ftrst number is greater than the second number;

wherein the printer controller is selectively configurable to supply dot data for the first and second modes.
Optionally the printer includes a printer controller for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.
Optionally the printer includes a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:

(a) a fire signal is provided to nozzles at a first and nth position in each set of nozzles;

(b) a fire signal is provided to the next inward pair of nozzles in each set;

(c) in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired;
and (d) in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

Optionally the printer includes a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printer includes a printer controller for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the fust and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

Optionally the printer includes a printer controller for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

Optionally the printer includes a printer controller for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

Optionally the printer includes a printer controller for supplying data to a printhead module including:

at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally the printer includes a printer controller for supplying data to a printhead capable of printing a maximum of n of channels of print data, the printhead being configurable into:

a first mode, in which the printhead is configured to receive print data for a first number of the channels;
and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

Optionally the printer includes a printer controller for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.
Optionally the printer includes a printer controller for supplying data to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printer includes a printer controller for supplying data to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:

in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

Optionally the printer includes a printer controller for supplying data to a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

Optionally the printer includes a printer controller for supplying data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally the printer includes a printer controller for supplying data to a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.
Optionally the printer includes a printer controller for supplying data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

Optionally the pfinter includes a printer controller for providing data to a printhead module that includes:
at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally the printer includes a printer controller for supplying data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

Optionally the printer includes a printer controller for supplying data to a printhead module comprising a plurality 5 of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

10 In a ninth aspect the present invention provides a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to 15 output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

20 Optionally the printhead modules are configured such that no dot data passes between them.

Optionally the printer includes at least one synchronization means between the first and second printer controllers for synchronizing the supply of dot data by the printer controllers.

25 Optionally each of the printer controllers is configurable to supply the dot data to printhead modules of a plurality of different lengths.

Optionally the printhead is a pagewidth printhead.

30 In a further aspect the present invention provides a print engine comprising:
a carrier;

a printhead comprising first and second elongate printhead modules, the printhead modules being mounted parallel to each other end to end on the carrier on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

Optionally the printhead modules are configured such that no dot data passes between them.

Optionally the print engine includes at least one synchronization means between the first and second printer controllers for synchronizing the supply of dot by the printer controllers.

Optionally each of the printer controllers is configurable to supply the dot data to printhead modules of a plurality of different lengths.

Optionally the printhead is a pagewidth printhead.

Optionally the printer controller is for implementing a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier, the nozzles being disposed on the printhead module, the method comprising the steps of:

(a) detennining the rotational displacement;

(b) deterrrtining at least one correction factor that at least partially compensates for the ink dot displacement;
and (c) using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

Optionally the printer controller is for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printer controller is for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:

(a) providing a fire signal to nozzles at a first and nth position in each set of nozzles;
(b) providing a fire signal to the next inward pair of nozzles in each set;

(c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and (d) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

Optionally the printer controller is manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.
Optionally the printer controller supplies data to a printhead module including:

at least one row of print nozzles;

at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.
Optionally the printer controller is installed in a printer comprising:

a printhead comprising at least a first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

Optionally the printer controller is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

Optionally the printer controller is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the fnst ptinthead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

Optionally the printer controller supplies dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:

access a correction factor associated with the at least one printhead module;

deternine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being deten:nined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

Optionally the printer controller supplies dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

Optionally the printer controller controls a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the noz.zles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

Optionally the printer controller outputs to a printhead module:
dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;

the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.

Optionally the printer controller supplies data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally the printer controller supplies print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:

a first mode, in which the printhead module is configured to receive data for a fust number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;

wherein the printer controller is selectively configurable to supply dot data for the first and second modes.
Optionally the printer controller supplies data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally the printer controller supplies one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:

(a) a fire signal is provided to nozzles at a first and nth position in each set of nozzles;
5 (b) a fire signal is provided to the next inward pair of nozzles in each set;

(c) in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired;
and (d) in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

Optionally the printer controller supplies one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printer controller supplies dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

Optionally the printer controller supplies dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the pfinter controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a con-esponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

Optionally the printer controller receives first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.
Optionally the printer controller supplies data to a printhead module including:

at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally the printer controller supplies data to a printhead capable of printing a maximum of n of channels of print data, the printhead being configurable into:

a first mode, in which the printhead is configured to receive print data for a first number of the channels;
and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

Optionally the printer controller supplies data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally the printer controller supplies data to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printer controller supplies data to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:

in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

Optionally the printer controller supplies data to a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

Optionally the printer controller supplies data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally the printer controller supplies data to a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

Optionally the printer controller supplies data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

Optionally the printer controller supplies data to a printhead module that includes:
at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally the printer controller supplies data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

Optionally the printer controller supplies data to a printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on ptint media at or adjacent a position where the faulty nozzle would otherwise have printed it.

In a tenth aspect the present invention provides printer controller for supplying dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:

access a correction factor associated with the at least one printhead module;

determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

Optionally, the nozzles are disposed in a plurality of rows, and the printer controller is configured to reallocate at least one of the ink dots from at least one original print line to at least one alternate print line, thereby to effect the at least partial compensation.

Optionally the printer controller is configured to retrieve the correction factor from a memory associated with the printhead.

Optionally, the memory is mounted with the printhead, the printhead being mounted on the print engine.

Optionally, the rotational displacement is roll.

Optionally, the rotational displacement is yaw.

Optionally, the printhead module being one of a plurality of printhead modules mounted on a carrier to form a printhead and the error in ink dot placement being an error relative to ink dots output by one or more of the other printhead modules Optionally, the printhead module is part of a printhead comprising a plurality of the modules, the printer controller being configured to determine an order in which at least some of the dot data is supplied to a plurality of the printhead modules, the order being determined at least partly on the basis of one or more of the correction factors, thereby to at least partially compensate for the rotational displacement of the plurality of the printheads.
Optionally, the correction factor is at least partially based on a thickness of media being printed on.

Optionally the printer controller configured to at least improve first order continuity between ink dots printed by adjacent printhead modules.

Optionally a print engine including the print controller according and a plurality of the printhead modules that define a printhead, the print engine being configured to compensate for the rotational displacement of at least one of the printhead modules.

Optionally the print engine further including a memory for storing the correction factor in a form accessible to the printer controller.

Optionally the print engine is configured to alter a timing of fire signals supplied to at least one of the nozzles on the basis of the correction factor, thereby to further effect the at least partial compensation.

Optionally the print engine is configured to supply the altered fire signals are to both reallocated ink dots and non-reallocated ink dots.

Optionally the printhead is a pagewidth printhead.

Optional a printer including a printer controller for supplying dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead 5 module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:

access a correction factor associated with the at least one printhead module;

detemnine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being deten:nined at least partly on the basis of the correction factor, thereby to at 10 least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

Optionally the printer further including a pagewidth printhead comprising a plurality of the printhead modules.
15 Optionally the printer controller is for implementing a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to ecroneous rotational displacement of a printhead module relative to a carrier, the nozzles being disposed on the printhead module, the method comprising the steps of:

(a) determining the rotational displacement;

20 (b) determining at least one correction factor that at least partially compensates for the ink dot displacement;
and (c) using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

25 Optionally the printer controller is for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printer controller is for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:

(a) providing a fire signal to nozzles at a first and nth position in each set of nozzles;
(b) providing a fire signal to the next inward pair of nozzles in each set;

(c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and (d) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

Optionally the printer controller is manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.

Optionally the printer controller for supplying data to a printhead module including:
at least one row of print nozzles;

at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

Optionally the printer controller is installed in a printer comprising:

a printhead comprising at least a first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

Optionally the piinter controller installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

Optionally the printer controller installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the pri.nthead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

Optionally the printer controller installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

Optionally the printer controller supplies dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.
Optionally the printer controller controls a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of fuing of the nozzles.

Optionally the printer controller outputs to a printhead module:

dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;

the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.

Optionally the printer controller supplies data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally the printer controller supplies data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:

a fust mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;

wherein the printer controller is selectively configurable to supply dot data for the first and second modes.
Optionally the printer controller supplies data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in fonming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally the printer controller supplies one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:

(a) a fire signal is provided to nozzles at a first and nth position in each set of nozzles;
(b) a fire signal is provided to the next inward pair of nozzles in each set;

(c) in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired;
and (d) in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

Optionally the printer controller supplies one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printer controller supplies dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

Optionally the printer controller supplies dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.
Optionally the printer controller receives fust data and manipulates the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

Optionally the printer controller supplies data to a printhead module including:
at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

5 Optionally the printer controller supplies data to a printhead capable of printing a maximum of n of channels of print data, the printhead being configurable into:

a first mode, in which the printhead is configured to receive print data for a first number of the channels;
and a second mode, in which the printhead is configured to receive print data for a second number of the 10 channels, wherein the first number is greater than the second number.

Optionally the printer controller supplies data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally the printer controller supplies data to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printer controller supplies data to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:

in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

Optionally the printer controller supplies data to a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

Optionally the printer controller supplies data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally the printer controlier supplies data to a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentialiy fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

Optionally the printer controller supplies data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

Optionally the printer controller supplies data to a printhead module that includes:
at least one row of print nozzles;

at least fust and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally the printer controller supplies data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

Optionally the printer controller supplies data to a printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

In an eleventh aspect the present invention provides printer controller for supplying dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

Optionally the printer controller is configured to modify the operation of the nozzles at or adjacent the at least one thermal sensor, such that operation of nozzles not at or adjacent the at least one thermal sensor is not modified.
Optionally each thermal sensor is associated with a predetermined group of the nozzles, the printer controller being configured to modify operation of the nozzles in the predetermined group for which the temperature has risen above the first threshold.

Optionally each thermal sensor is associated with a single nozzle.

Optionally the modification includes the printer controller preventing operation of the nozzle.

Optionally the modification includes the printer controller preventing operation of the nozzle for a predetermined period.

Optionally the modification includes the printer controller preventing operation of the nozzle until the temperature drops below a second threshold.

Optionally the second threshold is lower than the first threshold.
Optionally the second threshold is the same as the first threshold.

Optionally the temperature is not determined explicitly by the at least one thermal sensor or the module.
Optionally each of the nozzles including a thermal ink ejection mechanism.

Optionally the thermal sensor comprises at least part of one of the thermal inkjet mechanisms.
Optionally the thennal sensor comprises a heating element.

Optionally the thermal sensor determines the temperature by determining a resistance of the heating element.
Optionally the printer controller is configured to:

receive thermal infonmation from the at least one thenmal sensor, determine the modification based on the thermat information; and send control information back to the printhead module, the control information being indicative of the modification to make to the operation of the one or more nozzles.

Optionally a print engine including a printer controller configured to:
receive thermal information from the at least one thermal sensor, determine the modification based on the thermal information; and send control information back to the printhead module, the control information being indicative of the modification to make to the operation of the one or more nozzles; and a printhead module, wherein the printhead module further includes a plurality of data latches, the data latches being configured to provide dot data to respective ones of the nozzles, at least some of the data latches being configured to receive thermal signals from respective ones of the thermal sensors during an acquisition period.

Optionally the data latches are configured to form a shift register, the shift register being configured to:
shift the print data in during a print load phase;

sample the signals from the thermal sensors during a temperature load phase;
and shift the thermal signals out to the printer controller during an output phase.
Optionally the output phase coincides with a subsequent print load phase.

Optionally the print engine further includes logic circuitry configured to perform a bitwise operation on: each thermal signal as it is clocked out of the shift register; and each piece of dot data to be clocked into the shift register, such that when a thermal signal is indicative of a thermal problem with a nozzle, the logic circuitry prevents loading of data that would cause firing of that nozzle.

Optionally the logic circuitry includes an AND circuit that receives as inputs the dot data and the thermal signal corresponding to the nozzle for which the dot data is intended; an output of the AND circuit being in communication with an input of the shift register.

Optionally each thermal sensor is associated with a pair of the nozzles.

Optionally the printer controller is for implementing a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier, the nozzles being disposed on the printhead module, the method comprising the steps of:

(a) determining the rotational displacement;

(b) determining at least one correction factor that at least partially compensates for the ink dot displacement;
and (c) using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

Optionally the printer controller is for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printer controller is for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:

5 (a) providing a fire signal to nozzles at a first and nth position in each set of nozzles;
(b) providing a fire signal to the next inward pair of nozzles in each set;

(c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and (d) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

Optionally the printer controller is manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.

Optionally the printer controller supplies data to a printhead module including:
at least one row of print nozzles;

at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

Optionally the printer controller is installed in a printer comprising:

a printhead comprising at least a first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

Optionally the printer controller is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

Optionally the printer controller is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

Optionally the printer controller is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data for the, printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

Optionally the printer controller supplies dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:
access a conection factor associated with the at least one printhead module;

determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational dispiacement; and supply the dot data to the printhead module.

Optionally the printer controller controls a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

Optionally the printer controller outputs to a printhead module:
dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;

the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.

Optionally the printer controller supplies data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally the printer controller supplies print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:

a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;

wherein the printer controller is selectively configurable to supply dot data for the first and second modes.
Optionally the printer controller supplies data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally the printer controller supplies one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:

(a) a fire signal is provided to nozzles at a first and nth position in each set of nozzles;
(b) a fire signal is provided to the next inward pair of nozzles in each set;

(c) in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired;
and (d) in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

Optionally the printer controller supplies one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printer controller supplies dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective con-esponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

Optionally the printer controller supplies dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

Optionally the printer controller receives first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.
Optionally the printer controller supplies data to a printhead module including:

at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally the printer controller supplies data to a printhead capable of printing a maximum of n of channels of print data, the printhead being configurable into:

a first mode, in which the printhead is configured to receive print data for a first number of the channels;
and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

Optionally the printer controller supplies data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally the printer controller supplies data to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printer controller supplies data to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:

in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

Optionally the printer controller supplies data to a printhead module for receiving dot data to be printed using at 5 least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

Optionally the printer controller supplies data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion 10 including a component in a direction normal to that of a pagewidth to be printed.

Optionally the printer controller supplies data to a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, 15 the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fred before the nozzles of each subsequent row.

Optionally the printer controller supplies data to a printhead module comprising at least first and second rows 20 configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

Optionally the printer controller supplies data to a printhead module that includes:
at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally the printer controller supplies data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

Optionally the printer controller supplies data to a printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

Optionally the printer controller further includes a logic circuit accepting as inputs a masking signal and the thermal signal corresponding to the nozzle for which the dot data is intended, the logic circuit outputting the thermal signal to the input of the AND circuit in reliance on a value of the masking signal.

Optionally the value of the masking signal enables masking of the thermal signal for at least one nozzle position, including the nozzle for which the current dot data is intended.

Optionally the value of the masking signal enables masking of the thermal signal for a plurality of nozzle positions corresponding to a region of the printhead associated the nozzle for which the current dot data is intended.

Optionally the value of the masking signal enables masking of the thermal signal for all of the nozzle positions of the printhead.

In a twelfth aspect the present invention provides a printer controller for controlling a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

Optionally the one or more control signals include a fire control sequence indicative of a first fire group to be fired.

Optionally, the printhead being configured to shift the fire control sequence through a shift register to cause subsequent firing of the second and any other fire groups, wherein the printer controller is configured to provide the fire control sequence during an initiation phase of the printhead, such that the fire control sequence does not need to be repeatedly provided by the printer controller whi(e printing is taking place.

Optionally, the printhead being configured to shift the fire control sequence through a shift register to cause subsequent fuing of the second and any other fire groups, wherein the printer controller is configured to provide the fire control sequence periodically during printing.

Optionally the printhead being configured to provide the fire control sequence on a per row or per print-line basis.

Optionally the printhead being configured to provide a fire enable signal in addition to the one or more fire control signals, such that the combination of the fire enable and fire control signals cause selected ones of the nozzles to fire in the predetermined sequence and in accordance with a predeternuned timing.

In a further aspect the present invention provides a print engine including a printhead and a printer controller, the printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

Optionally the one or more control signals include a fire control sequence indicative of a first fire group to be fired.

Optionally the printhead being configured to shift the fire control sequence through a shift register to cause subsequent firing of the second and any other fire groups, wherein the printer controller is configured to provide the fire control sequence during an initiation phase of the printhead, such that the fire control sequence does not need to be repeatedly provided by the printer controller while printing is taking place.

Optionally, the printhead being configured to shift the fire control sequence through a shift register to cause subsequent firing of the second and any other fire groups, wherein the printer controller is configured to provide the fire control sequence periodically during printing.

Optionally the print engine being configured to provide the fire control sequence on a per row or per print-line basis.

Optionally the print engine being configured to provide a fire enable signal in addition to the one or more fire control signals, such that the combination of the fire enable and fire control signals cause selected ones of the nozzles to fire in the predetermined sequence and in accordance with a predetermined timing.

Optionally the printer controller is for implementing a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier, the nozzles being disposed on the printhead module, the method comprising the steps of:

(a) determining the rotational displacement;

(b) determining at least one correction factor that at least partially compensates for the ink dot displacement;
and (c) using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

Optionally the printer controller is for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printer controller is for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of (a) providing a fire signal to nozzles at a first and nth position in each set of nozzles;
(b) providing a fire signal to the next inward pair of nozzles in each set;

(c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and (d) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

Optionally the printer controller is manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.

Optionally the printer controller supplies data to a printhead module including:
at least one row of print nozzles;

at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

Optionally the printer controller is installed in a printer comprising:

a printhead comprising at least a first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

Optionally the printer controller is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

Optionally the printer controller is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

Optionally the printer controller is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

Optionally the printer controller supplies dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:
access a correction factor associated with the at least one printhead module;

determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being detennined at least partly on the basis of the con=ection factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

Optionally the printer controller supplies dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

Optionally the printer controller outputs to a printhead module:
dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;

the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.
Optionally the printer controller supplies data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally the printer controller supplies print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:

a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;

wherein the printer controller is selectively configurable to supply dot data for the first and second modes.
Optionally the printer controller supplies data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally the printer controller supplies one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:

(a) a fire signal is provided to nozzles at a first and nth position in each set of nozzles;

(b) a fire signal is provided to the next inward pair of nozzles in each set;

(c) in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired;
and (d) in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

Optionally the printer controller supplies one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position l, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printer controller supplies dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

Optionally the printer controller supplies dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a con:esponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.
Optionally the printer controller receives first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.
Optionally the printer controller supplies data to a printhead module including:

at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally the printer controller supplies data to a printhead capable of printing a maximum of n of channels of print data, the printhead being configurable into:

a first mode, in which the printhead is configured to receive print data for a first number of the channels;
and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

Optionally the printer controller supplies data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally the printer controller supplies data to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printer controller supplies data to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:

in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

Optionally the printer controller supplies data to a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

Optionally the printer controller supplies data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally the printer controller supplies data to a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

Optionally the printer controller supplies data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direc6on of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

Optionally the printer controller supplies data to a printhead module that includes:
at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally the printer controller supplies data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

Optionally the printer controller supplies data to a printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

Optionally the printhead module includes a plurality of pairs of the rows, each pair of rows including an odd row and an even row, the odd and even rows in each pair being offset from each other in both x and y directions relative to an intended direction of print media movement relative to the printhead, the printer controller being configured to control the at least one printhead module to cause firing of at least a plurality of the odd rows prior to firing any of the even rows, or vice versa.

Optionally all the odd rows are fired before any of the even rows are fired, or vice versa.

Optionally the printer controller configurable to control the printhead module such that the odd rows, or the even rows, or both, are fired in a predetermined order.

Optionally the printer controller configurable such that the predetennined order is selectable from a plurality of predetermined available orders.

Optionally the predetermined order is sequential.

Optionally the printer controller configurable such that the predetermined order can commence at any of a plurality of the rows.

In a thirteenth aspect the present invention provides a printer controller for outputting to a printhead module:
dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;

the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.

Optionally the communication output is configured to output the dot data and control data serially.

Optionally the printer controller further includes a plurality of the communication outputs.

Optionally the printer controller further includes a plurality of the communication outputs.

Optionally a print engine comprising a print controller and a plurality of printhead modules, the printhead modules being disposed end to end for printing a width exceeding that of any of the individual printhead modules, the communications input of each of the printhead modules being connected to a common dot data and control data bus, the common dot data and control data bus being in functional communication with the communication output.

Optionally each module is configured to respond to dot data and control data on the bus only when it is intended for that module.

Optionally a printer incorporating a print engine comprising a print controller and a plurality of printhead modules, the printhead modules being disposed end to end for printing a width exceeding that of any of the individual printhead modules, the communications input of each of the printhead modules being connected to a common dot data and control data bus, the conunon dot data and control data bus being in functional communication with the communication output.

Optionally a printer incorporating a print controller for outputting to a printhead module:
dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;

the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.
Optionally the printhead modules together form a pagewidth printhead.

Optionally the printer further including a pagewidth printhead comprising a plurality of the printhead modules.
Optionally the printer controller is for implementing a method of at least partially compensating for errors in ink dot placement by at least.one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier, the nozzles being disposed on the printhead module, the method comprising the steps of:

(a) detennining the rotational displacement;

(b) determining at least one correction factor that at least partially compensates for the ink dot displacement;
and (c) using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

Optionally the printer controller is for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.
Optionally the printer controller is for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:

(a) providing a fire signal to nozzles at a first and nth position in each set of nozzles;
(b) providing a fire signal to the next inward pair of nozzles in each set;

(c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and (d) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

Optionally the printer controller is manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.

Optionally the printer controller supplies data to a printhead module including:

at least one row of print nozzles;

at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.
Optionally the printer controller is installed in a printer comprising:

a printhead comprising at least a first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a connnon input of the printhead.

Optionally the printer controller is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the fust printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.
Optionally the printer controller is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

Optionally the printer controller is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the fust printer controller.

Optionally the printer controller supplies dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:
access a correction factor associated with the at least one printhead module;

detennine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

Optionally the printer controller supplies dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thennal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.
Optionally the printer controller controls a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a piintable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

Optionally the printer controller supplies data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally the printer controller supplies print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:

a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number, wherein the printer controller is selectively configurable to supply dot data for the first and second modes.
Optionally the printer controller supplies data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally the printer controller supplies one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:

(a) a fire signal is provided to nozzles at a fust and nth position in each set of nozzles;
(b) a fire signal is provided to the next inward pair of nozzles in each set;

(c) in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired;
and (d) in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

Optionally the printer controller supplies one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printer controller supplies dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

Optionally the printer controller supplies dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.
Optionally the printer controller receives f rst data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

Optionally the printer controller supplies data to a printhead module including:
at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally the printer controller supplies data to a printhead capable of printing a maximum of n of channels of print data, the printhead being configurable into:

a first mode, in which the printhead is configured to receive print data for a first number of the channels;
and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

Optionally the printer controller supplies data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally the printer controller supplies data to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printer controller supplies data to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:

in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and.then to fire the central nozzle.

Optionally the printer controller supplies data to a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling piinting of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

Optionally the printer controller supplies data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally the printer controller supplies data to a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

Optionally the printer controller supplies data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to'the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

Optionally the printer controller provides data to a printhead module that includes:
at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally the printer controller supplies data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

Optionally the printer controller supplies data to a printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a conesponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

In a fourteenth aspect the present invention provides a printer controller for supplying data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed, the printer controller being configured to control order and timing of the data supplied to the printhead such that the dropped row is compensated for during printing by the printhead module.

Optionally the displaced row portion is disposed adjacent one end of the printhead module.

Optionally the printhead module includes a plurality of the rows, wherein each of at least a plurality of the rows includes one of the displaced row portions.

Optionally the displaced row portions of at least some of the rows are different in length than the displaced row portions of at least some of the other rows.

Optionally each of the rows has a displaced row portion, and the sizes of the respective displaced row portions increase from row to row in the direction normal to that of the pagewidth to be printed.

Optionally the printer controller supplies the data to a printhead comprising a plurality of the printhead modules.
Optionally the printer controller supplies data to a printhead comprising a plurality of the printhead modules, wherein the displaced row portion of at least one of the printhead modules is disposed adjacent another of the printhead modules.

Optionally the printhead modules are the same shape and configuration as each other, and are ananged end to end across the intended print width.

Optionally, the printhead being a pagewidth printhead.
Optionally, the printhead being a pagewidth printhead.

Optionally the printer controller is for implementing a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier, the nozzles being disposed on the printhead module, the method comprising the steps of:

(a) determining the rotational displacement;

(b) determining at least one correction factor that at least partially compensates for the ink dot displacement;
and (c) using the correction factor to alter the output of the ink dots to at least partially compensate for the rotationai displacement.

Optionally the printer controller is for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.
Optionally the printer controller is for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:

(a) providing a fire signal to nozzles at a first and nth position in each set of nozzles;
(b) providing a fire signal to the next inward pair of nozzles in each set;

(c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and (d) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

Optionally the printer controller is manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.

Optionally the printer controller supplies data to a printhead module including:
at least one row of print nozzles;

at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

Optionally the printer controller is installed in a printer comprising:

a printhead comprising at least a first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

Optionally the printer controller is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the fust printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

Optionally the piinter controller is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the fust printhead module and the second printhead module; and the second ptinter controller outputs dot data only to the second printhead module.

Optionally the printer controller is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

Optionally the printer controller supplies dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:

access a correction factor associated with the at least one printhead module;

determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

Optionally the printer controller supplies dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a fust threshold.

Optionally the printer controller controls a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of fuing of the nozzles.

Optionally the printer controller outputs to a printhead module:
dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;

the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.

Optionally the printer controller supplies print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:

a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;

wherein the printer controller is selectively configurable to supply dot data for the first and second modes.
Optionally the printer controller supplies data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally the printer controller supplies one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:

(a) a fire signal is provided to nozzles at a first and nth position in each set of nozzles;
(b) a fire signal is provided to the next inward pair of nozzles in each set;

(c) in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired;
and (d) in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

Optionally the printer controller supplies one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fre signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printer controller supplies dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

Optionally the printer controller supplies dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the fust row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

Optionally the printer controller receives first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.
Optionally the printer controller supplies data to a printhead module including:

at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally the printer controller supplies data to a printhead capable of printing a maximum of n of channels of print data, the printhead being configurable into:

a first mode, in which the printhead is configured to receive print data for a first number of the channels;
and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

Optionally the printer controller supplies data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally the printer controller supplies data to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printer controller supplies data to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a fust and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:

in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

Optionally the printer controller supplies data to a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

Optionally the printer controller supplies data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally the printer controller supplies data to a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

Optionally the printer controller supplies data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

Optionally the printer controller supplies data to a printhead module that includes:
at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally the printer controller supplies data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

Optionally the printer controller supplies data to a printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a cotresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

In a fifteenth aspect the present invention provides printer controller for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:

a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;

wherein the printer controller is selectively configurable to supply dot data for the first and second modes.

Optionally the first number is n.

Optionally the fust number is less than n.

Optionally the printhead module is configurable into at least one other mode, in which the at least one printhead module is configured to receive print data for a third number of print channels other than the first and second numbers, the printer controller being selectively configurable to supply the print data for the third number of print channels.

Optionally n is 4 and the second number is less than 4.

Optionally n is 5 and the second number is less than 5.
Optionally n is 6 and the second number is less than 6.
Optionally the second number is 3, 4 or 5.

Optionally the print engine includes the print controller for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:

a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;

wherein the printer controller is selectively configurable to supply dot data for the first and second modes;
and the at least one printhead module.

Optionally the mode is selected based on the contents of a memory associated with the at least one printhead module.

Optionally the memory is a register.

Optionally the register is on an integrated circuit fonning part of the print engine.

Optionally the printer includes a printer controller for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:

a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;

wherein the printer controller is selectively configurable to supply dot data for the first and second modes.
Optionally the printer includes a print engine including the print controller for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:

a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;

wherein the printer controller is selectively configurable to supply dot data for the first and second modes;
and the at least one printhead module.

Optionally the printer includes a printer controller for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:

a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;

wherein the printer controller is selectively configurable to supply dot data for the first and second modes; and including a pagewidth printhead comprising a plurality of the printhead modules capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:

a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;

wherein the printer controller is selectively configurable to supply dot data for the first and second modes.
Optionally the printer controller for implementing a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier, the nozzles being disposed on the printhead module, the method comprising the steps of:
(a) determining the rotationaI displacement;

(b) determining at least one con-ection factor that at least partially compensates for the ink dot displacement;
and (c) using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

Optionally the printer controller for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.
Optionally the printer controller for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:

(a) providing a fire signal to nozzles at a first and nth position in each set of nozzles;
(b) providing a fire signal to the next inward pair of nozzles in each set;

(c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and (d) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

Optionally the printer controller manufactured in accordance with a method of manufacturing a plurality of ptinthead modules, at (east some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.
Optionally the printer controller supplies data to a printhead module including:

at least one row of print nozzles;

at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.
Optionally the printer controller installed in a printer comprising:

a printhead comprising at least a first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

Optionally the printer controller installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.
Optionally a printer controller installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the fust printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

Optionally the printer controller installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

Optionally the printer controller supplies dot data to at least one printhead module and at least partially compensating for errors in ink dot piacement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:
access a conection factor associated with the at least one printhead module;

determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

Optionally the printer controller supplies dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

Optionally the printer controller controls a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.
Optioaally the printer controller outputs to a printhead module:

dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;

the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.
Optionally the printer controller supplies data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction nonnal to that of a pagewidth to be printed.

Optionally the printer controller supplies data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally the printer controllers supplies one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that (a) a fire signal is provided to nozzles at a first and nth position in each set of nozzles;
(b) a fire signal is provided to the next inward pair of nozzles in each set;

(c) in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired;
and (d) in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

WO 2005/120835 PcT/AU2004/000706 Optionally the printer controller supplies one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printer controller supplies dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

Optionally the printer controller supplies dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.
Optionally the printer controller receives first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

Optionally the printer controller supplies data to a printhead module including:
at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally the printer controller supplies data to a printhead capable of printing a maximum of n of channels of print data, the printhead being configurable into:

a fust mode, in which the printhead is configured to receive print data for a first number of the channels;
and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

Optionally the printer controller supplies data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally the printer controller suppties data to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

, Optionally the printer controller supplies data to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:

in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

Optionally the printer controller supplies data to a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

Optionally the printer controller supplies data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction nonnal to that of a pagewidth to be printed.

Optionally the printer controller supplies data to a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

Optionally the printer controller supplies data to a printhead module comprising at least first and second rows configured to print ink of a'similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

Optionally the printer controller supplies data to a printhead module that includes:
at least one row of print nozzles;

at least first and second shift regist.ers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally the printer controller supplies data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

Optionally the printer controller supplies data to a printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

In a sixteenth aspect the present invention provides a printer controller for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally the printhead comprises a plurality of at least one of the types of module.

Optionally the printhead comprises a plurality of each of at least two of the types of module.
Optionally the printhead comprises two types of the module.

Optionally the two types of module alternate across a print width of the printhead.

Optionally, each of the modules including at least one row of print nozzles, wherein each of the at least one row of print nozzles includes at least a portion that extends at an acute angle to an intended relative direction of movement between the printhead and print media.

Optionally the different types of modules are configured, and arranged relative to each other, such that there is substantially no growth in offset of each of the at least one row of print nozzles in a direction across an intended print width of the printhead.

Optionally each of the printhead modules is a monolithic integrated circuit.

Optionally, each of the modules including at least one row of print nozzles, wherein each of the at least one rows includes at least two sub-rows, each of the sub-rows being parallel to each other and displaced relative to each other in a direction of intended movement of print media relative to the printhead.

Optionally at least one row in each of the printhead modules prints an ink corresponding to at least one row on an adjacent printhead module, wherein the corresponding rows of at least two of the different printhead modules are offset from each other in a direction of intended movement of print media relative to the printhead, Optionally the printhead being a pagewidth printhead.

Optionally the printhead being a pagewidth printhead.

Optionally, the printhead being a pagewidth printhead.

Optionally the printer controller is for implementing a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier, the nozzles being disposed on the printhead module, the method comprising the steps of:

(a) determining the rotational displacement;

(b) determining at least one correction factor that at least partially compensates for the ink dot displacement;
and (c) using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

Optionally the printer controller is for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.
Optionally the printer controller is for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:

(a) providing a fire signal to nozzles at a first and nth position in each set of nozzles;
(b) providing a fire signal to the next inward pair of nozzles in each set;

(c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and (d) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

Optionally the printer controller is manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.

Optionally the printer controller supplies data to a printhead module including:
at least one row of print nozzles;

at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

Optionally the printer controller is installed in a printer comprising:

a printhead comprising at least a first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a conunon input of the printhead.

Optionally the printer controller is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

Optionally the printer controller is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is ionger than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

Optionally the printer controller is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

Optionally the printer controller supplies dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:
access a correction factor associated with the at least one printhead module;

determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

Optionally the printer controller supplies dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.
Optionally the printer controller controls a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

Optionally the printer controller outputs to a printhead module:
dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;

the printer controller including at least one conununication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.

Optionally the printer controller supplies data to a pcinthead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally the printer controller supplies print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:

a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number, wherein the printer controller is selectively configurable to supply dot data for the first and second modes.
Optionally the printer controller supplies one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:

(a) a fire signal is provided to nozzles at a first and nth position in each set of nozzles;
(b) a fire signal is provided to the next inward pair of nozzles in each set;

(c) in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired;
and (d) in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

Optionally the printer controller supplies one or more control signals to a printhead module, the piinthead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printer controller supplies dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

Optionally the printer controller supplies dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.
Optionally the printer controller receives first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.
Optionally the printer controller supplies data to a printhead module including:

at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally the printer controller supplies data to a printhead capable of printing a maximum of n of channels of print data, the printhead being configurable into:

a first mode, in which the printhead is configured to receive print data for a first number of the channels;
and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

Optionally the printer controller supplies data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in fonning the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally the printer controller supplies data to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1; nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printer controller supplies data to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:

in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

Optionally the printer controller supplies data to a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

Optionally the printer controller supplies data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally the printer controller supplies data to a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

Optionally the printer controller supplies data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

Optionally the printer controller supplies data to a printhead module that includes:
at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally the printer controller supplies data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

Optionally the printer controller supplies data to a printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a simiiar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

In a seventeenth aspect the present invention provides printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:

(a) a fire signal is provided to nozzles at a first and nth position in each set of nozzles;
(b) a fire signal is provided to the next inward pair of nozzles in each set;

(c) in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired;
and (d) in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

Optionally the printhead module includes a plurality of the rows of nozzles, the printer controller being configured to control the printhead module such that steps (a) to (d) are repeated for each of the rows of nozzles.

Optionally the rows are disposed in pairs.

Optionally the rows in each pair of rows are offset relative to each other.
Optionally each pair of rows is configured to print the same color ink.
Optionally each pair of rows is connected to a common ink source.

Optionally the sets of nozzles are adjacent each other.

Optionally the sets of nozzles are separated by an intermediate nozzle, the intennediate nozzle being fired either prior to the nozzle at position I in each set, or following the nozzle at position n.

Optionally the printhead module is one of a plurality of printhead modules that form a pagewidth printhead, the printer controller being configure to supply the control signals to at least a plurality of the printhead modules.

Optionally the printer controller is for implementing a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier, the nozzles being disposed on the printhead module, the method comprising the steps of:

(a) determining the rotational displacement;

(b) determining at least one correction factor that at least partially compensates for the ink dot displacement;
and (c) using the correction factor to alter the output of the ink dots to at least partially compensate for the rotatidnal displacement.

Optionally the printer controller is for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.
Optionally the printer controller is for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:

(a) providing a fire signal to nozzles at a first and nth position in each set of nozzles;
(b) providing a fire signal to the next inward pair of nozzles in each set;

(c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and (d) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

Optionally the printer controller is manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.

Optionally the printer controller supplies data to a printhead module including:

at least one row of print nozzles;

at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

Optionally the printer controller is installed in a printer comprising:

a printhead comprising at least a first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

Optionally the printer controller is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

Optionally the printer controller is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

Optionally the printer controller is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the.print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the fust printer controller.

Optionally the printer controller supplies dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:
access a correction factor associated with the at least one printhead module;

determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

Optionally the printer controller supplies dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thennal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.
Optionally the printer controller controls a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

Optionally the printer controller outputs to a printhead module:

dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;

the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.

Optionally the printer controller supplies data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally the printer controller supplies print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:

a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;

wherein the printer controller is selectively configurable to supply dot data for the first and second modes.
Optionally the printer controller supplies data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally the printer controller supplies one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printer controller supplies dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

Optionally the printer controller supplies dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.
Optionally the printer controller receives first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

Optionally the printer controller supplies data to a printhead module including:
at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally the printer controller supplies data to a printhead capable of printing a maximum of n of channels of print data, the printhead being configurable into:

a first mode, in which the printhead is configured to receive print data for a first number of the channels;
and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

Optionally the printer controller supplies data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally the printer controller supplies data to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printer controller supplies data to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:

in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

Optionally the printer controller supplies data to a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

Optionally the printer controller supplies data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally the printer controller supplies data to a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simiiltaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

Optionally the printer controller supplies data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

Optionally the printer controller supplies data to a printhead module that includes:
at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally the printer controller supplies data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

Optionally the printer controller supplies data to a printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

Optionally the printhead module includes a plurality of the rows, the printer controller being configured to cause firing of each nozzle in each row simultaneously with the nozzle or nozzles at the same position in the other rows.
Optionally the printer controller includes a plurality of pairs of the rows, each pair of rows including an odd row and an even row, the odd and even rows in each pair being offset from each other in both x and y directions relative to an intended direction of print media movement relative to the printhead, the printer controller being configured to control the at least one printhead module to cause firing of at least a plurality of the odd rows prior to firing any of the even rows, or vice versa.

Optionally all the odd rows are fired before any of the even rows are fired, or vice versa.

Optionally the printer controller is configured to control the printhead such that the odd rows, or the even rows, or both, are fired in a predetermined order.

Optionally the printer controller is configurable such that the predetenmined order is selectable from a plurality of predetermined available orders.

Optionally the predetennined order is sequential.

Optionally the printer controller is configurable such that the predetermined order can commence at any of a plurality of the rows.

In an eighteenth aspect the present invention provides printer controller for supplying one or more controI signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printer controller is configured to cause the nozzle at each given position within the set to be fired simultaneously with the nozzles in the other sets at respective corresponding positions.

Optionally the printhead module includes a plurality of the rows of nozzles, the printer controller being configured to control the printhead module such that the steps are repeated for each of the rows of nozzles.

Optionally the rows are disposed in pairs.

Optionally the rows in each pair of rows are offset relative to each other.
Optionally each pair of rows is configured to print the same color ink.

Optionally each pair of rows is connected to a common ink source.

Optionally the sets of nozzles are adjacent each other.

Optionally the sets of nozzles are separated by an intermediate nozzle, the intermediate nozzle being fired either prior to the nozzle at position 1 in each set, or following the nozzle at position n.

Optionally the printhead module is one of a plurality of printhead modules that form a pagewidth printhead, the printer controller being configure to supply the control signals to at least a plurality of the printhead modules.

Optionally the printer controller is for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:

(a) providing a fire signal to nozzles at a first and nth position in each set of nozzles;
(b) providing a fire signal to the next inward pair of nozzles in each set;

(c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and (d) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

Optionally the printer controller is manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.

Optionally the printer controller supplies data to a printhead module including:
at least one row of print nozzles;

at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

Optionally the printer controller is installed in a printer comprising:

a printhead comprising at least a first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a connnon input of the printhead.

Optionally the printer controller is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

Optionally the printer controller is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

Optionally the printer controller is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules'being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

Optionally the printer controller supplies dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:

access a correction factor associated with the at least one printhead module;

detennine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

Optionally the printer controller supplies dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thennal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

Optionally the printer controller controls a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

Optionally the printer controller outputs to a printhead module:
dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;

the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.

Optionally the printer controller supplies data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally the printer controller supplies print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:

a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;

wherein the printer controller is selectively configurable to supply dot data for the first and second modes.
Optionally the printer controller supplies data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally the printer controller supplies one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printer controller supplies dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are piinted to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

Optionally the printer controller supplies dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the piinter controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.
Optionally the printer controller receives first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

Optionally the printer controller supplies data to a printhead module including:
at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each slrift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally the printer controller supplies data to a printhead capable of printing a maximum of n of channels of print data, the printhead being configurable into:

a first mode, in which the printhead is configured to receive print data for a first number of the channels;
and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

Optionally the printer controller supplies data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally the printer controller supplies data to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printer controller supplies data to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:

in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

Optionally the printer controller supplies data to a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

Optionally the printer controller supplies data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally the printer controller supplies data to a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

Optionally the printer controller supplies data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the fust pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

Optionally the printer controller supplies data to a printhead module that includes:

at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally the printer controller supplies data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a fust threshold.

Optionally the printer controller supplies data to a printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

Optionally the printhead module includes a plurality of the rows, the printer controller being configured to cause firing of each nozzle in each row simultaneously with the nozzle or nozzles at the same position in the other rows.
Optionally the printer controller includes a plurality of pairs of the rows, each pair of rows including an odd row and an even row, the odd and even rows in each pair being offset from each other in both x and y directions relative to an intended direction of print media movement relative to the printhead, the printer controller being configured to control the at least one printhead module to cause firing of at least a plurality of the odd rows prior to firing any of the even rows, or vice versa.

Optionally all the odd rows are fired before any of the even rows are fired, or vice versa.

Optionally the printer controller is configured to control the printhead such that the odd rows, or the even rows, or both, are fired in a predetermined order.

Optionally the printer controller is configurable such that the predetermined order is selectable from a plurality of predetermined available orders.

Optionally the predetermined order is sequential.

Optionally the printer controller is configurable such that the predetennined order can commence at any of a plurality of the rows.

In a nineteenth aspect the present invention provides a printer controller for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the fust row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

Optionally print engine comprising a printer controller for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing; and a printhead module, wherein the printhead module is controllable such that either of the nozzles in each aligned pair of nozzles in the first and second rows can be selected to output ink for a selected dot to be printed on the print media.

Optionally in the event a nozzle in the first row is faulty, the corresponding nozzle in the second row is selected to output ink for a dot for which the faulty nozzle would otherwise have output ink.

Optionally the print engine includes a plurality of sets of the first and second rows.

Optionally each of the sets of the first and second rows is configured to print in a single color or ink type.

Optionally the first and second rows in at least one of the sets are separated by one or more rows from the other set or sets.

Optionally each of the rows includes an odd sub-row and an even sub-row, the odd and even sub-rows being offset with respect to each other in a direction of intended print media travel relative to the printhead.
Optionally the odd and even sub-rows are transversely offset relative to each other.

Optionally the print engine is configured such that the first and second rows are fired alternately.
Optionally the print engine comprises a plurality of the printhead modules.

Optionally a printer including a printer controller for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are ftred such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

Optionally a printer including a print engine comprising a printer controller for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing; and a printhead module, wherein the printhead module is controllable such that either of the nozzles in each aligned pair of nozzles in the first and second rows can be selected to output ink for a selected dot to be printed on the print media.

Optionally the printer controller is for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:

(a) providing a fire signal to nozzles at a first and nth position in each set of nozzles;
(b) providing a fire signal to the next inward pair of nozzles in each set;

(c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and (d) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

Optionally the printer controller is manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.

Optionally the printer controller supplies data to a printhead module including:
at least one row of print nozzles;

at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

Optionally the printer controller is installed in a printer comprising:

a printhead comprising at least a first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the fust and second printer controllers are connected to a common input of the printhead.

Optionally the printer controller is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

Optionally the printer controller is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

Optionally the printer controller is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

Optionally the printer controller supplies dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:
access a correction factor associated with the at least one printhead module;

determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the con-ection factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

Optionally the printer controller supplies dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.
Optionally the printer controller controls a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

Optionally the printer controller outputs to a printhead module:
dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;

the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.
Optionally the printer controller supplies data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally the printer controller supplies print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:

a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;

wherein the printer controller is selectively configurable to supply dot data for the first and second modes.

Optionally the printer controller supplies data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally the printer controller supplies one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printer controller supplies dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

Optionally the printer controller supplies dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least fust and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.
Optionally the printer controller receives first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

Optionally the printer controller supplies data to a printhead module including:
at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally the printer controller supplies data to a printhead capable of printing a maximum of n of channels of print data, the printhead being configurable into:

a first mode, in which the printhead is configured to receive print data for a first number of the channels;
and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

Optionally the printer controller supplies data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally the printer controller supplies data to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printer controller supplies data to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:

in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

Optionally the printer controller supplies data to a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communicarion input for receiving the dot data for the at least two colors and the control data.

Optionally the printer controller supplies data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally the printer controller supplies data to a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

Optionally the printer controller supplies data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intendeil media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

Optionally the printer controller supplies data to a printhead module that includes:
at least one row of print nozzles;

at least fust and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally the printer controller supplies data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

Optionally the printer controller supplies data to a printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

In a twentieth aspect the present invention provides a printer controller for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

Optionally a print engine comprising a printer controller for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it; and the at least one printhead module, wherein each nozzle in the first row is paired with a nozzle in the second row, such that each pair of nozzles is aligned in an intended direction of print media travel relative to the printhead module.

Optionally the print engine includes a plurality of sets of the first and second rows.

Optionally each of the sets of the first and second rows is configured to print in a single color or ink type.
Optionally each of the rows includes an odd and an even sub-row, the odd and even sub-rows being offset with respect to each other in a direction of print media travel relative to the printhead in use.

Optionally the odd and even sub-rows are transversely offset with respect to each other.

Optionally a printer including at least one printer controller for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

Optionally a printer includes at least one print engine comprising a printer controller for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the fust row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it; and the at least one printhead module, wherein each nozzle in the first row is paired with a nozzle in the second row, such that each pair of nozzles is aligned in an intended direction of print media travel relative to the printhead module.

Optionally the printer controller is for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps o (a) providing a fire signal to nozzles at a first and nth position in each set of nozzles;
(b) providing a fire signal to the next inward pair of nozzles in each set;

(c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and (d) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

Optionally the printer controller is manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.

Optionally the printer controller supplies data to a printhead module including:

at least one row of print nozzles;

at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

Optionally the printer controller is installed in a printer comprising:

a printhead comprising at least a first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

Optionally the printer controller is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

Optionally the printer controller is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

Optionally the printer controller is installed in a printer comprising:

WO 2005/120835 CA 02639307 2008-08-29 pCT/AU2004/000706 a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

Optionally the printer controller supplies dot data to at least one piinthead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:
access a correction factor associated with the at least one printhead module;

determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

Optionally the printer controller supplies dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.
Optionally the printer controller controls a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

Optionally the printer controller outputs to a printhead module:

dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;

the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.

Optionally the printer controller supplies data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

.10 Optionally the printer controller supplies print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:

a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number, wherein the printer controller is selectively configurable to supply dot data for the first and second modes.
Optionally the printer controller supplies data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally the printer controller supplies one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printer controller supplies dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

Optionally the printer controller supplies dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.
Optionally the printer controller receives fust data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

Optionally the printer controller supplies data to a printhead module including:
at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally the printer controller supplies data to a printhead capable of printing a maximum of n of channels of print data, the printhead being configurable into:

a first mode, in which the printhead is configured to receive print data for a first number of the channels;
and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

Optionally the printer controller supplies data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the ptinthead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally the printer controller supplies data to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printer controller supplies data to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:

in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

Optionally the printer controller supplies data to a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

Optionally the printer controller supplies data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a.pagewidth to be printed.

Optionally the printer controller supplies data to a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

Optionally the printer controller supplies data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the fust row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

Optionally the printer controller supplies data to a printhead module that includes:
at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally the printer controller supplies data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

Optionally the printer controller supplies data to a printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

In a twenty first aspect the present invention provides a printer controller for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead, wherein each of the serial outputs is configured to supply dot data for at least two channels of the at least one printhead.

Optionally the at least two channels include at least two color channels.
Optionally the at least two channels include at least one fixative channel.

Optionally the at least two channels include at least one infrared ink channel.

Optionally the first data includes one or more instructions associated with production of the dot data from the first data, the print controller including processing means for producing the dot data from the first data on the basis of the one or more instructions.

Optionally the printhead is a pagewidth printhead.

Optionally the printer controller is for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:

(a) providing a fire signal to nozzles at a first and nth position in each set of nozzles;
(b) providing a fire signal to the next inward pair of nozzles in each set;

(c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and (d) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

Optionally the printer controller is manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.

Optionally the printer controller supplies data to a printhead module including:
at least one row of print nozzles;

at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

Optionally the printer controller is installed in a printer comprising:

a printhead comprising at least a first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

Optionally the printer controller is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

Optionally the printer controller is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

Optionally the printer controller is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

Optionally the printer controller supplies dot data to at least one printhead module and at least partially compensating for en=ors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:
access a correction factor associated with the at least one printhead module;

determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

Optionally the printer controller supplies dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

Optionally the printer controller controls a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

Optionally the printer controller outputs to a printhead module:
dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;

the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.

Optionally the printer controller supplies data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally the printer controller supplies print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:

a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number, wherein the printer controller is selectively configurable to supply dot data for the first and second modes.
Optionally the printer controller supplies data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally the printer controller supplies one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printer controller supplies dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

Optionally the printer controller supplies dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the pcinter controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

Optionally the printer controller receives first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.
Optionally the printer controller supplies data to a printhead module including:

at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally the printer controller supplies data to a printhead capable of printing a maximum of n of channels of print data, the printhead being configurable into:

a first mode, in which the printhead is configured to receive print data for a first number of the channels;
and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

Optionally the printer controller supplies data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is detennined by its geometric shape in plan.

Optionally the printer controller supplies data to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printer controller supplies data to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:

in the event n is an even number, all of the nozzles in each set has been fired, and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

Optionally the printer controller supplies data to a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

Optionally the printer controller supplies data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally the printer controller supplies data to a ptinthead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row. ' Optionally the printer controller supplies data to a printhead module comprising at least first and second rows configured to print ink of 2 similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the p-inthead module being configurable such that the nozzles in the fust and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

Optionally the printer controller supplies data to a printhead module that includes:
at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally the printer controller supplies data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

Optionally the printer controller supplies data to a printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting inlc, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.
In a twenty second aspect the present invention provides a printhead module including:
at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally there is a one to one conespondence between the nozzles and respective elements of the first and second shift registers.

Optionally each of the shift registers supplies dot data to about half of the nozzles in a row.

Optionally the printhead module includes at least one pair of rows of the nozzles, the rows in each pair being offset in a direction parallel to the rows by half the intra-row nozzle spacing.

Optionally each of the at least two shift registers supplies dot data to at least some of the nozzles in at least the pair of rows.

Optionally the printhead module includes a plurality of the rows configured to print using at least two ink channels, the nozzles for each of the ink channels being fed the dot data from at least one pair of first and second registers.

Optionally the printhead module is configured to receive dot data to which a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier has been applied, the nozzles being disposed on the printhead module, the method comprising the steps of (a) determining the rotational displacement;

(b) detennining at least one correction factor that at least partially compensates for the ink dot displacement;
and (c) using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

Optionally the printhead module is configured to receive dot data to which a method of expelling ink has been applied, the method being applied to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printhead module is configured to receive dot data to which a method of expelling ink has been applied, the method being applied to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:

(a) providing a fire signal to nozzles at a first and nth position in each set of nozzles;
(b) providing a fire signal to the next inward pair of nozzles in each set;

(c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and (d) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

Optionally the printhead module is manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.

Optionally the printhead module further including:
at least one row of print nozzles;

at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

Optionally the printhead module is installed in a printer comprising:

a printhead comprising at least the first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

Optionally the printhead module is installed in a printer comprising:

a printhead comprising first and second elongate piinthead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the fust printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

Optionally the printhead module is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

Optionally the printhead module is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

Optionally the printhead module is in communication with a printer controller for supplying dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:

access a correction factor associated with the at least one printhead module;

determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

Optionally the printhead module is in communication with a printer controller for supplying dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

Optionally the printhead module is in communication with a printer controller for controlling a head comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

Optionally the printhead module is, in conununication with a printer controller for outputting to a printhead module:

dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;

the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.

Optionally the printhead module includes at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally the printhead module is in communication with a printer controller for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:

a fust mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number, wherein the printer controller is selectively configurable to supply dot data for the first and second modes.
Optionally the printhead module is in communication with a printer controller for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is detennined by its geometric shape in plan.

Optionally the printhead module is used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:

(a) a fire signal is provided to nozzles at a first and nth position in each set of nozzles;
(b) a fire signal is provided to the next inward pair of nozzles in each set;

(c) in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired;
and (d) in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

Optionally the printhead module is used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position z], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printhead module is in communication with a printer controller for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the fust and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

Optionally the printhead module is in communication with a printer controller for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

Optionally the printhead module is in communication with a printer controller for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

Optionally the printhead module further including:
at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally the printhead module being capable of printing a maximum of n of channels of print data, the printhead being configurable into:

a first mode, in which the printhead is configured to receive print data for a first number of the channels;
and a second mode, in which the printhead is configured to receive print data for a second number of the'channels, wherein the first number is greater than the second number.

Optionally a module further comprising a plurality of printhead modules including:
at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles; and the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is detenT-ined by its geometric shape in plan.

Optionally the printhead module includes at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printhead module further includes at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:

in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

Optionally a printhead module for receiving dot data to be printed using at least two different inks and controi data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

Optionally a printhead module further includes at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

Optionally a printhead module further comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

Optionally a printhead module is in communication with a printer controller for providing data to a printhead module that includes:

at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the therrnal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

Optionally a printhead module further comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

In a twenty third aspect the present invention provides a printhead module capable of printing a maximum of n of channels of print data, the printhead module being configurable into:

a first mode, in which the printhead module is configured to receive print data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

Optionally the first number is n.
Optionally the first number is less than n.

Optionally the printhead module is configurable into at least one other mode, in which the printhead is configured to receive print data for a number of print channels other than the first and second numbers.

Optionally n is 4 and the second number is less than 4.

Optionally n is 5 and the second number is less than 5.

Optionally n is 6 and the second number is less than 6.
Optionally the second number is 3, 4 or 5.

Optionally the selected mode is selected based on the contents of a memory associated with the printhead.
Optionally the memory is a register.

Optionally the register is on an integrated circuit, and wherein the integrated circuit and the printhead are mounted to a print engine.

Optionally printhead comprising a plurality of printhead modules capable of printing a maximum of n of channels of print data, the printhead module being configurable into:

a first mode, in which the printhead module is configured to receive print data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

Optionally printhead is a pagewidth printhead.

Optionally the printhead module is configured to receive dot data to which a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier has been applied, the nozzles being disposed on the printhead module, the method comprising the steps of:

(a) determining the rotational displacement;

(b) determining at least one conection factor that at least partially compensates for the ink dot displacement;
and (c) using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

Optionally the printhead module is configured to receive dot data to which a method of expelling ink has been applied, the method being applied to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printhead module is configured to receive dot data to which a method of expelling ink has been applied, the method being applied to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:

(a) providing a fire signal to nozzles at a first and nth position in each set of nozzles;
(b) providing a fire signal to the next inward pair of nozzles in each set;

(c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and (d) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

Optionally the printhead module is manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to fotm bilithic pagcwidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.
Optionally the printhead module further including:

at least one row of print nozzles;

at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

Optionally the printhead module is installed in a printer comprising:

a printhead comprising at least the first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the fust and second printer controllers are connected to a common input of the printhead.

Optionally the printhead module is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the ftrst printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

Optionally the printhead module is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

Optionally the printhead module is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

Optionally the printhead module is in conununication with a printer controller for supplying dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:

access a correction factor associated with the at least one printhead module;

determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being detemlined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

Optionally the printhead module is in communication with a printer controller for supplying dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

Optionally the printhead module is in communication with a printer controller for controlling a head comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagcwidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

Optionally the printhead module is, in conununication with a printer controller for outputting to a printhead module:

dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;

the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.
Optionally the printhead module includes at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally the printhead module is in communication with a printer controller for supplying piint data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:

a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number, wherein the printer controller is selectively configurable to supply dot data for the first and second modes.

Optionally the printhead module is in communication with a printer controller for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally the printhead module is used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:

(a) a fire signal is provided to nozzles at a first and nth position in each set of nozzles;
(b) a fire signal is provided to the next inward pair of nozzles in each set;

(c) in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired;
and (d) in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

Optionally the printhead module is used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printhead module is in communication with a printer controller for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

Optionally the printhead module is in communication with a printer controller for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

Optionally the printhead module is in communication with a printer controller for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

Optionally the printhead module further including:

at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally the printhead module being capable of printing a maximum of n of channels of print data, the printhead being configurable into:

a first mode, in which the printhead is configured to receive print data for a first number of the channels;
and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

Optionally a module further comprising a plurality of printhead modules including:
at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles; and the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally the printhead module includes at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printhead module further includes at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:

in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

Optionally a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

Optionally a printhead module further includes at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a ptintable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fue group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

Optionally a printhead module further comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

Optionally a printhead module is in communication with a printer controller for providing data to a printhead module that includes:

at least one row of print nozzles;

at least fust and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

Optionally a printhead module further comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

In a twenty fourth aspect the present invention provides a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally the printhead comprising a plurality of at least one of the types of module.
Optionally the printhead comprising a plurality of each of at least two of the types of module.

Optionally the printhead comprising two types of the module.

Optionally the two types of module altemate across a print width of the printhead.

Optionally each of the modules including at least one row of print nozzles, wherein each of the at least one row of print nozzles includes at least a portion that extends at an acute angle to an intended relative direction of movement between the printhead and print media.

Optionally the different types of modules are configured, and arranged relative to each other, such that there is substantially no growth in offset of each of the at least one row of print nozzles in a direction across an intended print width of the printhead.

Optionally each of the printhead modules is a monolithic integrated circuit.

Optionally each of the modules including at least one row of print nozzles, wherein each of the at least one rows includes at least two sub-rows, each of the sub-rows being parallel to each other and displaced relative to each other in a direction of intended movement of print media relative to the printhead.

Optionally the printhead being a pagewidth printhead.
Optionally the printhead being a pagewidth printhead.
Optionally the printhead being a pagewidth printhead_ Optionally the printhead is configured to receive dot data to which a method of at least partially compensating for etrors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier has been applied, the nozzles being disposed on the printhead module, the method comprising the steps of (a) determining the rotational displacement;

(b) determining at least one correction factor that at least partially compensates for the ink dot displacement;
and (c) using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

Optionally the printhead is configured to receive dot data to which a method of expelling ink has been applied, the method being applied to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printhead is configured to receive dot data to which a method of expelling ink has been applied, the method being applied to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:

(a) providing a fire signal to nozzles at a first and nth position in each set of nozzles;
(b) providing a fire signal to the next inward pair of nozzles in each set;

(c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and (d) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

Optionally the printhead is manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.

Optionally the printhead further including:
at least one row of print nozzles;

at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.
Optionally the printhead is installed in a printer comprising:

a printhead comprising at least the first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

Optionally the printhead is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the fust printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.
Optionally the printhead is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a.join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the fust printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

Optionally the printhead is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller, and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

Optionally the printhead is in communication with a printer controller for supplying dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:

access a correction factor associated with the at least one printhead module;

detenmine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

Optionally the printhead is in communication with a printer controller for supplying dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the pnnter controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

Optionally the printhead is in communication with a printer controller for controlling a head comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

Optionally the printhead is in communication with a printer controller for outputting to a printhead module:
dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;

the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.

Optionally the printhead further including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally the printhead is in communication with a printer controller for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:

a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;

wherein the printer controller is selectively configurable to supply dot data for the first and second modes.
Optionally the printhead is in communication with a printer controller for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally the printhead is used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:

(a) a fire signal is provided to nozzles at a first and nth position in each set of nozzles;
(b) a fire signal is provided to the next inward pair of nozzles in each set;

(c) in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired;
and (d) in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

Optionally the printhead is used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, WO 2005. PCT/AU2004/000706 nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printhead is in communication with a printer controller for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the fiust row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

Optionally the printhead is in communication with a printer controller for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

Optionally the printhead is in communication with a printer controller for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

Optionally the printhead further including:
at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally the printhead being capable of printing a maximum of n of channels of print data, the printhead being configurable into:

a first mode, in which the printhead is configured to receive print data for a first number of the channels;
and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

Optionally the printhead further including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printhead further including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:

in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

Optionally the printhead receives dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

Optionally the printhead further including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally the printhead having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

Optionally the printhead further comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

Optionally the printhead is in communication with a printer controller for providing data to a printhead module that includes:

at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally the printhead having a plurality of nozzles for expelling ink, the printhead module including a plurality of therrnal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

Optionally the printhead further comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

In a twenty fifth aspect the present invention provides a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the nozzle at each given position within the set is fired simultaneously with the nozzles in the other sets at respective corresponding positions.

Optionally the printhead module includes a plurality of the rows of nozzles, the printhead module being configured to fire all the nozzles on each row prior to firing any nozzles from a subsequent row.

Optionally the rows are disposed in pairs.

Optionally the rows in each pair of rows are offset relative to each other.
Optionally each pair of rows is configured to print the same color ink.

Optionally each pair of rows is connected to a common ink source.
Optionally the sets of nozzles are adjacent each other.

Optionally the sets of nozzles are separated by an intermediate nozzle, the interinediate nozzle being fired either prior to the nozzle at position 1 in each set, or following the nozzle at position n.

Optionally a printhead comprising a plurality of printhead modules including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printhead is a pagewidth printhead.

Optionally the printhead module is configured to receive dot data to which a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier has been applied, the nozzles being disposed on the printhead module, the method comprising the steps of:

(a) determining the rotational displacement;

(b) determining at least one correction factor that at least partially compensates for the ink dot displacement;
and (c) using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

Optionally the printhead module is configured to receive dot data to which a method of expelling ink has been applied, the method being applied to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printhead module is configured to receive dot data to which a method of expelling ink has been applied, the method being applied to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:

(a) providing a fire signal to nozzles at a first and nth position in each set of nozzles;
(b) providing a fire signal to the next inward pair of nozzles in each set;

(c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and (d) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

Optionally the printhead module is manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.

Optionally the printhead module further including:

at least one row of print nozzles;

at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

Optionally the printhead module is installed in a printer comprising:

a printhead comprising at least the first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

Optionally the printhead module is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the fust printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

Optionally the printhead module is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the fust printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

Optionally the printhead module is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the fust printer controller outputs dot data to both the first printhead module and the second controller, and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

Optionally the printhead module is in communication with a printer controller for supplying dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:

access a correction factor associated with the at least one printhead module;

determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

Optionally the printhead module is in communication with a printer controller for supplying dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

Optionally the printhead module is in communication with a printer controller for controlling a head comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

Optionally the printhead module is, in communication with a printer controller for outputting to a printhead module:

dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;

the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.

Optionally the printhead module includes at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally the printhead module is in communication with a printer controller for supplying print data to at least one printhead module capable of printing a tnaximum of n of channels of print data, the at least one printhead module being configurable into:

a first mode, in which the printhead module is configured to receive data for a first number of the channels; and .20 a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;

wherein the printer controller is selectively configurable to supply dot data for the first and second modes.
Optionally the printhead module is in communication with a printer controller for supplying data to a.printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in fonning the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally the printhead module is used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:

(a) a fire signal is provided to nozzles at a fust and nth position in each set of nozzles;

(b) a fire signal is provided to the next inward pair of nozzles in each set;

(c) in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired;
and (d) in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

Optionally the printhead module is used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printhead module is in communication with a printer controller for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or.color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the fust and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

Optionally the printhead module is in communication with a printer controller for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

Optionally the printhead module is in communication with a printer controller for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

Optionally the printhead module further including:
at Ieast one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally the printhead module being capable of printing a maximum of n of channels of print data, the printhead being configurable into:

a first mode, in which the printhead is configured to receive print data for a first number of the channels;
and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

Optionally a module further comprising a plurality of printhead modules including:
at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles; and the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally the printhead module includes at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printhead module further includes at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:

in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

Optionally a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

Optionally a printhead module further includes at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

Optionally a printhead module further comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

Optionally a printhead module is in communication with a printer controller for providing data to a printhead module that includes:

at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

Optionally a printhead module further comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least fust and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

Optionally the printhead module further comprising a plurality of the rows, the printhead module being configured to fire each nozzle in each row simultaneously with the nozzle or nozzles at the same position in the other rows.
Optionally the printhead module further including a plurality of pairs of the rows, each pair of rows including an odd row and an even row, the odd and even rows in each pair being offset from each other in both x and y directions relative to an intended direction of print media movement relative to the printhead, the printhead module being configured to cause firing of at least a plurality of the odd rows prior to firing any of the even rows, or vice versa.

Optionally all the odd rows are fired before any of the even rows are fired, or vice versa.

Optionally all the odd rows, or the even rows, or both, are fired in a predetennined order.

Optionally the printhead module is configurable such that the predetermined order is selectable from a plurality of predetermined available orders.

Optionally the predetermined order is sequential.

Optionally the printhead module is configurable such that the predetemzined order can commence at any of a plurality of the rows.

In a twenty sixth aspect the present invention provides a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the.
nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:

in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

Optionally the printhead module includes a plurality of the rows of nozzles, the printhead module being configured to fire all the nozzles on each row prior to fuing any nozzles from a subsequent row.
Optionally the rows are disposed in pairs.

Optionally the rows in each pair of rows are offset relative to each other.
Optionally each pair of rows is configured to print the same color ink.
Optionally each pair of rows is connected to a common ink source.

Optionally the sets of nozzles are adjacent each other.

Optionally the sets of nozzles are separated by an intermediate nozzle, the intermediate nozzle being fired either prior to the nozzle at position 1 in each set, or following the nozzle at position n.

Optionally the printhead module is configured to receive dot data to which a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier has been applied, the nozzles being disposed on the printhead module, the method comprising the steps of:
(a) determining the rotational displacement;

(b) determining at least one correction factor that at least partially compensates for the ink dot displacement;
and (c) using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

Optionally the printhead module is configured to receive dot data to which a method of expelling ink has been applied, the method being applied to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printhead module is configured to receive dot data to which a method of expelling ink has been applied, the method being applied to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:

(a) providing a fire signal to nozzles at a first and nth position in each set of nozzles;
(b) providing a fire signal to the next inward pair of nozzles in each set;

(c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and (d) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

Optionally the printhead module is manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.
Optionally the printhead module further including:

at least one row of print nozzles;

at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.
Optionally the printhead module is installed in a printer comprising:

a printhead comprising at least the first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

Optionally the printhead module is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

Optionally the printhead module is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the fust printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

Optionally the printhead module is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

Optionally the printhead module is in communication with a printer controller for supplying dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:

access a correction factor associated with the at least one printhead module;

determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

Optionally the printhead module is in communication with a printer controller for supplying dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

Optionally the printhead module is in communication with a printer controller for controlling a head comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

Optionally the printhead module is, in communication with a printer controller for outputting to a printhead module:

dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;

the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.
Optionally the printhead module includes at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally the printhead module is in communication with a printer controller for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:

a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;

wherein the printer controller is selectively configurable to supply dot data for the first and second modes.

Optionally the printhead module is in communication with a printer controller for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally the printhead module is used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:

(a) a fire signal is provided to nozzles at a fust and nth position in each set of nozzles;
(b) a fire signal is provided to the next inward pair of nozzles in each set;

(c) in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired;
and (d) in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

Optionally the printhead module is used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printhead module is in communication with a printer controller for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

Optionally the printhead module is in communication with a printer controller for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the fust row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

Optionally the printhead module is in communication with a printer controller for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

Optionally the printhead module further including:
at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally the printhead module being capable of printing a maximum of n of channels of print data, the printhead being configurable into:

a first mode, in which the printhead is configured to receive print data for a first number of the channels;
and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

Optionally a module further comprising a plurality of printhead modules including:
at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles; and the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally the printhead module includes at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printhead module fiuther includes at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:

in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

Optionally a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

Optionally a printhead module fiuther includes at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire graup, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

Optionally a printhead module further comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

Optionally a printhead module is in communication with a printer controller for providing data to a printhead module that includes:

at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

Optionally a printhead module further comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

Optionally the printhead module further comprising a plurality of the rows, the printhead module being configured to fire each nozzle in each row simultaneously with the nozzle or nozzles at the same position in the other rows.
Optionally the printhead module further including a plurality of pairs of the rows, each pair of rows including an odd row and an even row, the odd and even rows in each pair being offset from each other in both x and y directions relative to an intended direction of print media movement relative to the printhead, the printhead module being configured to cause firing of at least a plurality of the odd rows prior to firing any of the even rows, or vice versa.

Optionally all the odd rows are fired before any of the even rows are fired, or vice versa.

Optionally all the odd rows, or the even rows, or both, are fired in a predetermined order.

Optionally the printhead module is configurable such that the predetermined order is selectable from a plurality of predetermined available orders.

Optionally the predetem-ined order is sequential.

Optionally the printhead module is configurable such that the predetennined order can commence at any of a plurality of the rows.

In a twenty seventh aspect the present invention provides a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

Optionally the communication input is configured to receive the dot data and control data serially.
Optionally the printhead module further including a plurality of the communication inputs.
Optionally the printhead module further including a plurality of the communication inputs.

Optionally a printhead comprising a plurality of printhead modules for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data;

the printhead modules being disposed end to end for printing a width exceeding that of any of the individual printhead modules, the communications input of each of the printhead modules being connected to a conunon dot data and control data bus.

Optionally each module is configured to respond to dot data and control data on the bus only when it is intended for that module.

Optionally the printhead module is configured to receive dot data to which a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to en-oneous rotational displacement of a printhead module relative to a carrier has been applied, the nozzles being disposed on the printhead module, the method comprising the steps of:
(a) determining the rotational displacement;

(b) determining at least one correction factor that at least partially compensates for the ink dot displacement;
and (c) using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

Optionally the printhead module is configured to receive dot data to which a method of expelling ink has been applied, the method being applied to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle positionx], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printhead module is configured to receive dot data to which a method of expelling ink has been applied, the method being applied to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:

(a) providing a fire signal to nozzles at a first and nth position in each set of nozzles;
(b) providing a fire signal to the next inward pair of nozzles in each set;

(c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired, and (d) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

Optionally the printhead module is manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.
Optionally the printhead module further including:

at least one row of print nozzles;

at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.
Optionally the printhead module is installed in a printer comprising:

a printhead comprising at least the first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

Optionally the printhead module is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

Optionally the printhead module is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

Optionally the printhead module is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

Optionally the printhead module is in communication with a printer controller for supplying dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a canier, the printer being configured to:

access a correction factor associated with the at least one printhead module;

determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

Optionally the printhead module is in communication with a printer controller for supplying dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

Optionally the printhead module is in communication with a printer controller for controlling a head comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

Optionally the printhead module is, in communication with a printer controller for outputting to a printhead module:

dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;

the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.
Optionally the printhead module includes at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally the printhead module is in communication with a printer controller for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:

a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;

wherein the printer controller is selectively configurable to supply dot data for the first and second modes.

Optionally the printhead module is in communication with a printer controller for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally the printhead module is used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:

(a) a fire signal is provided to nozzles at a first and nth position in each set of nozzles;
(b) a fire signal is provided to the next inward pair of nozzles in each set;

(c) in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired;
and (d) in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

Optionally the printhead module is used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printhead module is in communication with a printer controiler for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzl'es from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

Optionally the printhead module is in communication with a printer controller for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

Optionally the printhead module is in communication with a printer controller for receiving first data and manipulating the fust data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

Optionally the printhead module further including:
at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally the printhead module being capable of printing a maximum of n of channels of print data, the printhead being configurable into:

a first mode, in which the printhead is configured to receive print data for a first number of the channels;
and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

Optionally a module further comprising a plurality of printhead modules including:
at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles; and the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally the printhead module includes at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printhead module futther includes at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:

in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

Optionally a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

Optionally a printhead module further includes at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

Optionally a printhead module further comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

Optionally a printhead module is in communication with a printer controller for providing data to a printhead module that includes:

at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of therlnal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

Optionally a printhead module further comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

In a twenty eighth aspect the present invention provides a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally the displaced row portion is disposed adjacent one end of the monolithic printhead module.

Optionally the printhead module further including a plurality of the rows, wherein each of at least a plurality of the rows includes one of the displaced row portions.

Optionally the displaced row portions of at least some of the rows are different in length than the displaced row portions of at least some of the other rows.

Optionally each of the rows has a displaced row portion, and the sizes of the respective displaced row portions increase from row to row in the direction normal to that of the pagewidth to be printed.

Optionally the dropped rows together comprise a generally trapezoidal shape, in plan.
Optionally the dropped rows together comprise a generally triangular shape, in plan.

Optionally a printhead comprising a plurality of printhead modules, including at least one of the printhead modules including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally a printhead comprising a plurality of printhead modules, including at least one the printhead modules according to claim 2, wherein the displaced row portion of at least one of the printhead modules is disposed adjacent another of the printhead modules.

Optionally the printhead modules are the same shape and configuration as each other, and are arranged end to end across the intended print width.

Optionally the printhead being a pagewidth printhead.
Optionally the printhead being a pagewidth printhead.

Optionally the printhead module is configured to receive dot data to which a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to ecroneous rotational displacement of a printhead module relative to a carrier has been applied, the nozzles being disposed on the printhead module, the method comprising the steps of:

(a) determining the rotational displacement;, (b) determining at least one con:ection factor that at least partially compensates for the ink dot displacement;
and (c) using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

Optionally the printhead module is configured to receive dot data to which a method of expelling ink has been applied, the method being applied to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printhead module is configured to receive dot data to which a method of expelling ink has been applied, the method being applied to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:

(a) providing a fire signal to nozzles at a first and nth position in each set of nozzles;
(b) providing a fire signal to the next inward pair of nozzles in each set;

(c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and (d) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzie-in each set have been fired, and then firing the central nozzle.

Optionally the printhead module is manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.

Optionally the printhead module further including:

at least one row of print nozzles;

at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

Optionally the printhead module is installed in a printer comprising:

a printhead comprising at least the first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the fust and second printer controllers are connected to a common input of the printhead.

Optionally the printhead module is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the fust printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

Optionally the printhead module is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

Optionally the printhead module is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

Optionally the printhead module is in conununication with a printer controller for supplying dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:

access a correction factor associated with the at least one printhead module;

determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

Optionally the printhead module is in conununication with a printer controller for supplying dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

Optionally the printhead module is in communication with a printer controller for controlling a head comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

Optionally the printhead module is, in communication with a printer controller for outputting to a printhead module:

dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;

the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.

Optionally the printhead module includes at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally the printhead module is in communication with a printer controller for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:

a fust mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number, wherein the printer controller is selectively configurable to supply dot data for the first and second modes.
Optionally the printhead module is in communication with a printer controller for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally the printhead module is used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:

(a) a fire signal is provided to nozzles at a first and nth position in each set of nozzles;

(b) a fire signal is provided to the next inward pair of nozzles in each set;

(c) in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired;
and (d) in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

Optionally the printhead module is used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printhead module is in communication with a printer controller for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

Optionally the printhead module is in communication with a printer controller for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

Optionally the printhead module is in communication with a printer controller for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

Optionally the printhead module further including:
at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally the printhead module being capable of printing a maximum of n of channels of print data, the printhead being configurable into:

a first mode, in which the printhead is configured to receive print data for a first number of the channels;
and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

Optionally a module further comprising a plurality of printhead modules including:
at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles; and the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally the printhead module includes at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printhead module further includes at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:

in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fred, and then to fire the central nozzle.

Optionally a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

Optionally a printhead module further includes at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

Optionally a printhead module further comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

Optionally a printhead module is in communication with a printer controller for providing data to a printhead module that includes:

at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

Optionally a printhead module further comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a con-esponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

In a twenty ninth aspect the present invention provides a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

Optionally the rows are disposed in pairs extending generally transverse to a direction media is to be moved relative to the printhead.

Optionally the rows in each pair of rows are configured to print the same color ink as each other.
Optionally the rows in each pair of rows share an ink supply.

Optionally the rows in each pair of rows are offset with respect to each other.

Optionally the printhead module is configured to fire the nozzles such that at least some ink dots from one row land on top of dots previously deposited by one or more of the other rows.

Optionally the printhead module is operable in at least two fire modes, wherein at least some of the at least two fire modes define relatively different numbers of nozzles in each of the fire groups.

Optionally at least some of the at least two fire groups define relatively different fire group sequences.
Optionally a printhead comprising a plurality of printhead modules having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

Optionally the printhead is a pagewidth printhead.

Optionally the printhead module is configured to receive dot data to which a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier has been applied, the nozzles being disposed on the printhead module, the method comprising the steps of:
(a) determining the rotational displacement;

(b) determining at least one coirection factor that at least partially compensates for the ink dot displacement;
and (c) using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

Optionally the printhead module is configured to receive dot data to which a method of expelling ink has been applied, the method being applied to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printhead module is configured to receive dot data to which a method of expelling ink has been applied, the method being applied to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of (a) providing a fire signal to nozzles at a first and nth position in cach set of nozzles;
(b) providing a fire signal to the next inward pair of nozzles in each set;

(c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and (d) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

Optionally the printhead module is manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.
Optionally the printhead module further including:

at least one row of print nozzles;

at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.
Optionally the printhead module is installed in a printer comprising:

a printhead comprising at least the first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

Optionally the printhead module is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the fust printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

Optionally the printhead module is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

Optionally the printhead module is installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

Optionally the printhead module is in communication with a printer controller for supplying dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:

access a correction factor associated with the at least one printhead module;

determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

Optionally the printhead module is in communication with a printer controller for supplying dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

Optionally the printhead module is in communication with a printer controller for controlling a head comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each frre group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

Optionally the printhead module is, in communication with a printer controller for outputting to a printhead module:

dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;

the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.

Optionally the printhead module includes at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally the printhead module is in communication with a printer controller for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:

a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;

wherein the printer controller is selectively configurable to supply dot data for the first and second modes.

Optionally the printhead module is in communication with a printer controller for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally the printhead module is used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:

(a) a fire signal is provided to nozzles at a first and nth position in each set of nozzles;
(b) a fire signal is provided to the next inward pair of nozzles in each set;

(c) in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired;
and (d) in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

Optionally the printhead module is used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printhead module is in communication with a printer controller for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the ficst and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

Optionally the printhead module is in communication with a printer controller for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the fust row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

Optionally the printhead module is in communication with a printer controller for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

Optionally the printhead module further including:
at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally the printhead module being capable of printing a maximum of n of channels of print data, the printhead being configurable into:

a fust mode, in which the printhead is configured to receive print data for a first number of the channels;
and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

Optionally a module further comprising a plurality of printhead modules including:
at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles; and the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

Optionally the printhead module includes at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

Optionally the printhead module further includes at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:

in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

Optionally a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

Optionally a printhead module further includes at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

Optionally a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

Optionally a printhead module further comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

Optionally a printhead module is in communication with a printer controller for providing data to a printhead module that includes:

at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

Optionally a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

Optionally a printhead module further comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a conesponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

Optionally the printhead module further comprises a plurality of the rows, the printhead module being configured to fire each nozzle in each row simultaneously with the nozzle or nozzles at the same position in the other rows.

Optionally the printhead module further includes a plurality of pairs of the rows, each pair of rows including an odd row and an even row, the odd and even rows in each pair being offset from each other in both x and y directions relative to an intended direction of print media movement relative to the printhead, the printhead module being configured to cause firing of at least a plurality of the odd rows prior to firing any of the even rows, or vice versa.

Optionally all the odd rows are fired before any of the even rows are fired, or vice versa.
Optionally all the odd rows, or the even rows, or both, are fired in a predetermined order.

Optionally the printhead module is configurable such that the predetermined order is selectable from a plurality of predetermined available orders.

Optionally the predetermined order is sequential.

Optionally the printhead module is configurable such that the predetermined order can commence at any of a plurality of the rows.

In a thirtieth aspect the present invention provides a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second rows are fired such that some dots output to print media are printed to by nozzles from the first row and at least some other dots output to print media are printed to by nozzles from the second row.

Optionally the printhead module is controllable such that either of the nozzles in each aligned pair of nozzles in the first and second rows can be selected to output ink for a selected dot to be printed on the print media.
Optionally in the event a nozzle in the first row is faulty, the corresponding nozzle in the second row is selected to output ink for a dot for which the faulty nozzle would otherwise have output ink.
Optionally the printhead module includes a plurality of sets of the first and second rows.

Optionally each of the sets of the first and second rows is configured to print in a single color or ink type.

Optionally the first and second rows in at least one of the sets are separated by one or more rows from the other set or sets.

Optionally each of the rows includes an odd sub-row and an even sub-row, the odd and even sub-rows being offset with respect to each other in a direction of intended print media travel relative to the printhead.
Optionally the odd and even sub-rows are transversely offset relative to each other.

Optionally the printhead module is configured such that the first and second rows are fired altemately.

Optionally a printhead comprising a plurality of printhead modules comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second rows are fired DEMANDES OU BREVETS VOLUMINEUX
LA PRESENTE PARTIE DE CETTE DEMANDE OU CE BREVETS
COMPREND PLUS D'UN TOME.

CECI EST LE TOME DE _3 NOTE: Pour les tomes additionels, veillez contacter le Bureau Canadien des Brevets.

JUMBO APPLICATIONS / PATENTS

THIS SECTION OF THE APPLICATION / PATENT CONTAINS MORE
THAN ONE VOLUME.

NOTE- For additional volumes please contact the Canadian Patent Office.

Claims (162)

1. A method of expelling ink from a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence:
[nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.
2. A method according to claim 1,wherein the nozzle at each given position within the set is fired simultaneously with the nozzles in the other sets at respective corresponding positions.
3. A method according to claim 1,wherein the printhead module includes a plurality of the rows of nozzles, the method including sequentially repeating the for each of the rows of nozzles.
4. A method according to claim 3, wherein the rows are disposed in pairs.
5. A method according to claim 4, wherein the rows in each pair of rows are offset relative to each other.
6. A method according to claim 5, wherein each pair of rows is configured to print the same color ink.
7. A method according to claim 6, wherein each pair of rows is connected to a common ink source.
8. A method according to claim 1,wherein the sets of nozzles are adjacent each other.
9. A method according to claim 1,wherein the sets of nozzles are separated by an intermediate nozzle, the intermediate nozzle being fired either prior to the nozzle at position l in each set, or following the nozzle at position n.
10. A method according to claim l,including the step of providing the fire sequence to the printhead module from a printer controller, the fire signals being based on the fire sequence.
11. A method according to claim 10, wherein the fire sequence is loaded into a shift register in the printhead module.
12. A method according to claim 1,the method at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier, the nozzles being disposed on the printhead module, the method comprising the steps of:

(a) determining the rotational displacement;
(b) determining at least one correction factor that at least partially compensates for the ink dot displacement;
and (c) using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.
13. A method according to claim 1,the method including expelling ink from a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:
(a) providing a fire signal to nozzles at a first and nth position in each set of nozzles;
(b) providing a fire signal to the next inward pair of nozzles in each set;
(c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and (d) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.
14. A method according to claim 1,the method including manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.
15. A method according to claim 1,the method being performed in conjunction with a printhead module including:
at least one row of print nozzles;
at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.
16. A method according to claim l,the method being performed in a printer comprising:
a printhead comprising at least a first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.
17. A method according to claim 1,the method being performed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.
18. A method according to claim 1,the method being performed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.
19. A method according to claim 1,the method being performed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.
20. A method according to claim 1,the method being performed in conjunction with a printer controller for supplying dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:
access a correction factor associated with the at least one printhead module;
determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.
21. A method according to claim 1,the method being performed in conjunction with a printer controller for supplying dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.
22. A method according to claim 1,the method being performed in conjunction with a printer controller for controlling a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.
23. A method according to claim 1,the method being performed in conjunction with a printer controller for outputting to a printhead module:
dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;
the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.
24. A method according to claim 1,the method being performed in conjunction with a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.
25. A method according to claim 1,the method being performed in conjunction with a printer controller for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:
a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;
wherein the printer controller is selectively configurable to supply dot data for the first and second modes.
26. A method according to claim 1,the method being performed in conjunction with a printer controller for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.
27. A method according to claim 1,the method being used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:
providing a fire signal to nozzles at a first and nth position in each set of nozzles;
providing a fire signal to the next inward pair of nozzles in each set;
in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.
28. A method according to claim 1,the method being used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.
29. A method according to claim 1,the method being performed in conjunction with a printer controller for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.
30. A method according to claim 1,the method being performed in conjunction with a printer controller for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.
31. A method according to claim 1,the method being performed in conjunction with a printer controller for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead, wherein each of the serial outputs is configured to supply dot data for at least two channels of the at least one printhead.
32. A method according to claim 1,the method being performed in conjunction with a printhead module including:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.
33. A method according to claim 1,the method being performed in conjunction with a printhead capable of printing a maximum of n of channels of print data, the printhead being configurable into:
a first mode, in which the printhead is configured to receive print data for a first number of the channels; and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.
34. A method according to claim 1,the method being performed in conjunction with a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.
35. A method according to claim 1,the method being performed in conjunction with a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.
36. A method according to claim 1,the method being performed in conjunction with a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:
in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.
37. A method according to claim 1,the method being performed in conjunction with a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.
38. A method according to claim 1,the method being performed in conjunction with a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.
39. A method according to claim 1,the method being performed in conjunction with a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.
40. A method according to claim l,the method being performed in conjunction with a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.
41. A method according to claim 1,the method being performed in conjunction with a printer controller for providing data to a printhead module that includes:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.
42. A method according to claim 1,the method being performed in conjunction with a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.
43. A method according to claim 1,the method being performed in conjunction with a printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.
44. A method according to claim 1,wherein the printhead module includes a plurality of the rows, the method including firing each nozzle in each row simultaneously with the nozzle or nozzles at the same position in the other rows.
45. A method according to claim 1,including a plurality of pairs of the rows, each pair of rows including an odd row and an even row, the odd and even rows in each pair being offset from each other in both x and y directions relative to an intended direction of print media movement relative to the printhead, the method including causing firing of at least a plurality of the odd rows prior to firing any of the even rows, or vice versa.
46. A method according to claim 45, wherein all the odd rows are fired before any of the even rows are fired, or vice versa.
47. A method according to claim 45, wherein the odd rows, or the even rows, or both, are fired in a predetermined order.
48. A method according to claim 47, wherein the predetermined order is selectable from a plurality of predetermined available orders.
49. A method according to claim 45, wherein the predetermined order is sequential.
50. A method according to claim 49, wherein the predetermined order can commence at any of a plurality of the rows.
51. A method of expelling ink from a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:
(a) providing a fire signal to nozzles at a first and nth position in each set of nozzles;
(b) providing a fire signal to the next inward pair of nozzles in each set;
(c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and (d) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.
52. A method according to claim 51, wherein the printhead module includes a plurality of the rows of nozzles, the method including sequentially repeating steps (a) to (d) for each of the rows of nozzles.
53. A method according to claim 52, wherein the rows are disposed in pairs.
54. A method according to claim 53, wherein the rows in each pair of rows are offset relative to each other.
55. A method according to claim 54, wherein each pair of rows is configured to print the same color ink.
56. A method according to claim 55, wherein each pair of rows is connected to a common ink source.
57. A method according to claim 51, wherein the sets of nozzles are adjacent each other.
58. A method according to claim 51, wherein the sets of nozzles are separated by an intermediate nozzle, the intermediate nozzle being fired either prior to the nozzle at position 1 in each set, or following the nozzle at position n.
59. A method of expelling ink from a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence:
[nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.
60. A method according to claim 59, wherein the nozzle at each given position within the set is fired simultaneously with the nozzles in the other sets at respective corresponding positions.
61. A method according to claim 51, the method at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier, the nozzles being disposed on the printhead module, the method comprising the steps of:
(a) determining the rotational displacement;
(b) determining at least one correction factor that at least partially compensates for the ink dot displacement;
and (c) using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.
62. A method according to claim 51, the method including expelling ink from a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.
63. A method according to claim 51, the method including manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.
64. A method according to claim 51, the method being performed in conjunction with a printhead module including:
at least one row of print nozzles;
at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.
65. A method according to claim 51, the method being performed in a printer comprising:

a printhead comprising at least a first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.
66. A method according to claim 51, the method being performed in a printer comprising:
(a) a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;
(b) at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.
67. A method according to claim 51, the method being performed in a printer comprising:
(a) a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

(b) at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.
68. A method according to claim 51, the method being performed in a printer comprising:
(a) a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
(b) at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.
69. A method according to claim 51, the method being performed in conjunction with a printer controller for supplying dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:
(a) access a correction factor associated with the at least one printhead module;
(b) determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and (c) supply the dot data to the printhead module.
70. A method according to claim 51, the method being performed in conjunction with a printer controller for supplying dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.
71. A method according to claim 51, the method being performed in conjunction with a printer controller for controlling a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.
72. A method according to claim 51, the method being performed in conjunction with a printer controller for outputting to a printhead module:
dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;
the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.
73. A method according to claim 51, the method being performed in conjunction with a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.
74. A method according to claim 51, the method being performed in conjunction with a printer controller for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:
(a) a first mode, in which the printhead module is configured to receive data for a first number of the channels; and (b) a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;
(c) wherein the printer controller is selectively configurable to supply dot data for the first and second modes.
75. A method according to claim 51, the method being performed in conjunction with a printer controller for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.
76. A method according to claim 51, the method being used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:
(d) providing a fire signal to nozzles at a first and nth position in each set of nozzles;
(e) providing a fire signal to the next inward pair of nozzles in each set;
(f) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and (g) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.
77. A method according to claim 51, the method being used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.
78. A method according to claim 51, the method being performed in conjunction with a printer controller for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.
79. A method according to claim 51, the method being performed in conjunction with a printer controller for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.
80. A method according to claim 51, the method being performed in conjunction with a printer controller for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead, wherein each of the serial outputs is configured to supply dot data for at least two channels of the at least one printhead.
81. A method according to claim 51, the method being performed in conjunction with a printhead module including:
(a) at least one row of print nozzles;

(b) at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.
82. A method according to claim 51, the method being performed in conjunction with a printhead capable of printing a maximum of n of channels of print data, the printhead being configurable into:
(a) a first mode, in which the printhead is configured to receive print data for a first number of the channels;
and (b) a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.
83. A method according to claim 51, the method being performed in conjunction with a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.
84. A method according to claim 51, the method being performed in conjunction with a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.
85. A method according to claim 51, the method being performed in conjunction with a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:
(a) in the event n is an even number, all of the nozzles in each set has been fired; and (b) in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.
86. A method according to claim 51, the method being performed in conjunction with a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.
87. A method according to claim 51, the method being performed in conjunction with a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.
88. A method according to claim 51, the method being performed in conjunction with a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.
89. A method according to claim 51, the method being performed in conjunction with a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.
90. A method according to claim 51, the method being performed in conjunction with a printer controller for providing data to a printhead module that includes:
(a) at least one row of print nozzles;
(b) at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.
91. A method according to claim 51, the method being performed in conjunction with a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.
92. A method according to claim 51, the method being performed in conjunction with a printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.
93. A method according to claim 51, wherein the printhead module includes a plurality of the rows, the method including firing each nozzle in each row simultaneously with the nozzle or nozzles at the same position in the other rows.
94. A method according to claim 51, wherein the printhead module includes a plurality of the rows, the method including firing each nozzle in each row simultaneously with the nozzle or nozzles at the same position in the other rows.
95. A method according to claim 51, including a plurality of pairs of the rows, each pair of rows including an odd row and an even row, the odd and even rows in each pair being offset from each other in both x and y directions relative to an intended direction of print media movement relative to the printhead, the method including causing firing of at least a plurality of the odd rows prior to firing any of the even rows, or vice versa.
96. A method according to claim 95, wherein all the odd rows are fired before any of the even rows are fired, or vice versa.
97. A method according to claim 95, wherein the odd rows, or the even rows, or both, are fired in a predetermined order.
98. A method according to claim 97, wherein the predetermined order is selectable from a plurality of predetermined available orders.
99. A method according to claim 95, wherein the predetermined order is sequential.
100. A method according to claim 99, wherein the predetermined order can commence at any of a plurality of the rows.
101. A method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.
102. A method of manufacturing a plurality of pagewidth printheads, the method comprising the steps of:
manufacturing a plurality of printhead modules in accordance with claim 1; and assembling pairs of at least some of the printhead modules to form pagewidth printheads, wherein each of the printhead modules in each pagewidth printhead is shorter than the pagewidth.
103. A method according to claim 102, wherein the printhead modules of at least one of the pagewidth printheads are of relatively different lengths.
104. A method according to claim 102, wherein the printhead modules of at least one of the pagewidth printheads are of the same length.
105. A method according to claim 102, wherein the printhead modules of at least one of the pagewidth printheads are of relatively different lengths, and the printhead modules of at least another of the pagewidth printheads are of the same length.
106. A method according to claim 102, wherein at least some of the printhead modules are larger than a reticle step used in laying out those printhead modules.
107. A method according to claim 101, including the step of laying out a plurality of left-handed and right-handed printhead modules.
108. A method according to claim 107, including the step of laying out a plurality of different lengths of left-handed and right-handed printhead modules.
109. A method according to claim 101, the method at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier, the nozzles being disposed on the printhead module, the method comprising the steps of:
(a) determining the rotational displacement;

(b) determining at least one correction factor that at least partially compensates for the ink dot displacement;
and (c) using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.
110. A method according to claim 101, the method including expelling ink from a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.
111. A method according to claim 101, the method including expelling ink from a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:
providing a fire signal to nozzles at a first and nth position in each set of nozzles;
providing a fire signal to the next inward pair of nozzles in each set;
in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.
112. A method according to claim 101, the method being performed in conjunction with a printhead module including:
at least one row of print nozzles;
at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.
113. A method according to claim 101, the method being performed in a printer comprising:
a printhead comprising at least a first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.
114. A method according to claim 101, the method being performed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.
115. A method according to claim 101, the method being performed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.
116. A method according to claim 101, the method being performed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.
117. A method according to claim 101, the method being performed in conjunction with a printer controller for supplying dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:
access a correction factor associated with the at least one printhead module;
determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.
118. A method according to claim 101, the method being performed in conjunction with a printer controller for supplying dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.
119. A method according to claim 101, the method being performed in conjunction with a printer controller for controlling a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.
120. A method according to claim 101, the method being performed in conjunction with a printer controller for outputting to a printhead module:
dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;
the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.
121. A method according to claim 101, the method being performed in conjunction with a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.
122. A method according to claim 101, the method being performed in conjunction with a printer controller for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:
a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;
wherein the printer controller is selectively configurable to supply dot data for the first and second modes.
123. A method according to claim 101, the method being performed in conjunction with a printer controller for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.
124. A method according to claim 101, the method being used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:
(a) providing a fire signal to nozzles at a first and nth position in each set of nozzles;
(b) providing a fire signal to the next inward pair of nozzles in each set;
(c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and (d) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.
125. A method according to claim 101, the method being used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.
126. A method according to claim 101, the method being performed in conjunction with a printer controller for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.
127. A method according to claim 101, the method being performed in conjunction with a printer controller for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.
128. A method according to claim 101, the method being performed in conjunction with a printer controller for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead, wherein each of the serial outputs is configured to supply dot data for at least two channels of the at least one printhead.
129. A method according to claim 101, the method being performed in conjunction with a printhead module including:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.
130. A method according to claim 101, the method being performed in conjunction with a printhead capable of printing a maximum of n of channels of print data, the printhead being configurable into:
a first mode, in which the printhead is configured to receive print data for a first number of the channels; and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.
131. A method according to claim 101, the method being performed in conjunction with a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.
132. A method according to claim 101, the method being performed in conjunction with a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.
133. A method according to claim 101, the method being performed in conjunction with a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:
in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.
134. A method according to claim 101, the method being performed in conjunction with a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.
135. A method according to claim 101, the method being performed in conjunction with a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.
136. A method according to claim 101, the method being performed in conjunction with a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.
137. A method according to claim 101, the method being performed in conjunction with a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.
138. A method according to claim 101, the method being performed in conjunction with a printer controller for providing data to a printhead module that includes:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.
139. A method according to claim 101, the method being performed in conjunction with a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.
140. A method according to claim 101, the method being performed in conjunction with a printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.
141. A printhead module including:
at least one row of print nozzles;
at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.
142. A printhead module according to claim 141, wherein there is a one to one correspondence between the nozzles and elements of the two shift registers.
143. A printhead module according to claim 142, wherein each of the shift registers supplies dot data to about half of the nozzles.
144. A printhead module according to claim 141, including at least one pair of rows of the nozzles, the rows in each pair being offset with respect to each other by half the intra-row nozzle spacing.
145. A printhead module according to claim 144, wherein each of the at least two shift registers supplies dot data to at least some of the nozzles in at least one pair of rows.
146. A printhead comprising a plurality of printhead modules according to claim 186.
147. A printhead according to claim 146, wherein the printhead is a pagewidth printhead.
148. A printhead module according to claim 141, configured to receive dot data to which a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier has been applied, the nozzles being disposed on the printhead module, the method comprising the steps of:
(a) determining the rotational displacement;
(b) determining at least one correction factor that at least partially compensates for the ink dot displacement;
and (c) using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.
149. A printhead module according to claim 141, configured to receive dot data to which a method of expelling ink has been applied, the method being applied to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.
150. A printhead module according to claim 141, configured to receive dot data to which a method of expelling ink has been applied, the method being applied to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:
(a) providing a fire signal to nozzles at a first and nth position in each set of nozzles;
(b) providing a fire signal to the next inward pair of nozzles in each set;
(c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and (d) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.
151. A printhead module according to claim 141, having been manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.
152. A printhead module according to claim 141, including:
at least one row of print nozzles;
at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.
153. A printhead module according to claim 141, installed in a printer comprising:
a printhead comprising at least the first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.
154. A printhead module according to claim 141, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.
155. A printhead module according to claim 141, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.
156. A printhead module according to claim 141, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.
157. A printhead module according to claim 141, in communication with a printer controller for supplying dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:
access a correction factor associated with the at least one printhead module;
determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.
158. A printhead module according to claim 141, in communication with a printer controller for supplying dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.
159. A printhead module according to claim 141, in communication with a printer controller for controlling a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.
160. A printhead module according to claim 141, in communication with a printer controller for outputting to a printhead module:
dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;
the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.
161. A printhead module according to claim 141, including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.
162. A printhead module according to claim 141, in communication with a printer controller for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:
a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;
wherein the printer controller is selectively configurable to supply dot data for the first and second modes.

208. A printhead module according to claim 141, in communication with a printer controller for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

164. A printhead module according to claim 141, used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:
(a) a fire signal is provided to nozzles at a first and nth position in each set of nozzles;
(b) a fire signal is provided to the next inward pair of nozzles in each set;
(c) in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired;
and (d) in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

165. A printhead module according to claim 141, used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

166. A printhead module according to claim 141, in communication with a printer controller for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

167. A printhead module according to claim 141, in communication with a printer controller for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

168. A printhead module according to claim 141, in communication with a printer controller for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

169. A printhead module according to claim 141, including:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

170. A printhead module according to claim 186 being capable of printing a maximum of n of channels of print data, the printhead being configurable into:
a first mode, in which the printhead is configured to receive print data for a first number of the channels; and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

171. A printhead comprising a plurality of printhead modules according to claim 141, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

172. A printhead module according to claim 141, including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

173. A printhead module according to claim 141, including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:
in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

174. A printhead module according to claim 141, for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

175. A printhead module according to claim 141, including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

176. A printhead module according to claim 141, having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

177. A printhead module according to claim 141, comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

178. A printhead module according to claim 141, in communication with a printer controller for providing data to a printhead module that includes:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

179. A printhead module according to claim 141, having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

180. A printhead module according to claim 141, comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

181. A printer comprising:
a printhead comprising at least a first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

182. A printer according to claim 181, including at least one synchronization means between the first and second printer controllers for synchronizing the supply of dot by the printer controllers.

183. A printer according to claim 181, configured such that the first and second printer controllers sequentially provide the dot data to the common input.

184. A printer according to claim 181, further including a second printhead module, the printer being configured such that: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

185. A printer according to claim 184, wherein the printhead modules are configured such that no dot data passes between them.

186. A printer according to claim 184, wherein each of the printer controllers is configurable to supply the dot data to printhead modules of a plurality of different lengths.

187. A printer according to claim 181, wherein the printhead is a pagewidth printhead.

188. A print engine comprising:
a carrier;
a printhead comprising at least a first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

189. A printer according to claim 188, including at least one synchronization means between the first and second printer controllers for synchronizing the supply of dot by the printer controllers.

190. A printer according to claim 188, configured such that the first and second printer controllers alternately provide the dot data to the common input.

191. A printer according to claim 188, further including a second printhead module, the printer being configured such that: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

192. A printer according to claim 191, wherein the printhead modules are configured such that no dot data passes between them.

193. A printer according to claim 191, wherein each of the printer controllers is configurable to supply the dot data to printhead modules of a plurality of different lengths.

194. A printer according to claim 188, wherein the printhead is a pagewidth printhead.
195. A printer comprising:
a printhead comprising at least a first elongate printhead module, the at least one printhead module including at least first and second rows of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to the printhead to supply data for the first and second rows of nozzles, respectively.

196. A printer according to claim 195, including at least one synchronization means between the first and second printer controllers for synchronizing the supply of dot by the printer controllers.

197. A printer according to claim 195, wherein the printhead modules are configured such that no dot data passes between them.

198. A printer according to claim 195, wherein the printhead is a pagewidth printhead.

199. A printer according to claim 181, for implementing a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier, the nozzles being disposed on the printhead module, the method comprising the steps of:

determining the rotational displacement;
determining at least one correction factor that at least partially compensates for the ink dot displacement; and using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

200. A printer according to claim 226 for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

201. A printer according to claim 181, for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:
(a) providing a fire signal to nozzles at a first and nth position in each set of nozzles;
(b) providing a fire signal to the next inward pair of nozzles in each set;
(c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and (d) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

202. A printer according to claim 181, manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.
203. A printer according to claim 181, including a printhead module including:
at least one row of print nozzles;
at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

204. A printer according to claim 181, comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

205. A printer according to claim 181, comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

206. A printer according to claim 181, comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

207. A printer according to claim 181, including at least one printhead module, configured for at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:
access a correction factor associated with the at least one printhead module;
determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

208. A printer according to claim 181, including a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

209. A printer according to claim 181, for controlling a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

210. A printer according to claim 181, including a printer controller for sending to a printhead:
dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;
the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.
211. A printer according to claim 181, including a printer controller for supplying data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.
212. A printer according to claim 181, including a printer controller for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:
a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;
wherein the printer controller is selectively configurable to supply dot data for the first and second modes.
213. A printer according to claim 181, including a printer controller for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

214. A printer according to claim 181, including a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:
(a) a fire signal is provided to nozzles at a first and nth position in each set of nozzles;
(b) a fire signal is provided to the next inward pair of nozzles in each set;

(c) in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired;
and (d) in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

215. A printer according to claim 181, including a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

216. A printer according to claim 181, including a printer controller for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

217. A printer according to claim 181, including a printer controller for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

218. A printer according to claim 181, including a printer controller for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

219. A printer according to claim 181, including a printer controller for supplying data to a printhead module including:
at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

220. A printer according to claim 181, including a printer controller for supplying data to a printhead capable of printing a maximum of n of channels of print data, the printhead being configurable into:
a first mode, in which the printhead is configured to receive print data for a first number of the channels; and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

221. A printer according to claim 181, including a printer controller for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

222. A printer according to claim 181, including a printer controller for supplying data to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

223. A printer according to claim 181, including a printer controller for supplying data to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:
in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

224. A printer according to claim 181, including a printer controller for supplying data to a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

270. A printer according to claim 181, including a printer controller for supplying data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.
226. A printer according to claim 181, including a printer controller for supplying data to a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

227. A printer according to claim 181, including a printer controller for supplying data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

228. A printer according to claim 181, including a printer controller for providing data to a printhead module that includes:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

229. A printer according to claim 181, including a printer controller for supplying data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

230. A printer according to claim 181, including a printer controller for supplying data to a printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.
231. A printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

232. A printer according to claim 231, including at least one synchronization means between the first and second printer controllers for synchronizing the supply of dot by the printer controllers.

233. A printer according to claim 231, wherein each of the printer controllers is configurable to supply the dot data to a printhead module of arbitrary length.

234. A printer according to claim 231, wherein the first and second printhead modules are equal in length.
235. A printer according to claim 231, wherein the first and second printhead modules are unequal in length.
236. A printer according to claim 231, wherein the printhead is a pagewidth printhead.

237. A print engine comprising:
a carrier;
a printhead comprising first and second elongate printhead modules, the printhead modules being mounted parallel to each other end to end on the carrier on either side of a join region;
at least first and second printer controllers mounted on the carrier and being configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

238. A print engine according to claim 237, including at least one synchronization means between the first and second printer controllers for synchronizing the supply of dot by the printer controllers.

239. A print engine according to claim 237, wherein each of the printer controllers is configurable to supply the dot data to a printhead module of arbitrary length.

240. A print engine according to claim 237, wherein the first and second printhead modules are equal in length.

241. A print engine according to claim 237, wherein the first and second printhead modules are unequal in length.

242. A print engine according to claim 237, wherein the printhead is a pagewidth printhead.

243. A printer according to claim 231, for implementing a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier, the nozzles being disposed on the printhead module, the method comprising the steps of:
determining the rotational displacement;
determining at least one correction factor that at least partially compensates for the ink dot displacement; and using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

244. A printer according to claim 276 for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

245. A printer according to claim 231, for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:
providing a fire signal to nozzles at a first and nth position in each set of nozzles;
providing a fire signal to the next inward pair of nozzles in each set;
in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

246. A printer according to claim 231, manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.

247. A printer according to claim 231, including a printhead module including:
at least one row of print nozzles;
at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

248. A printer according to claim 231, comprising:
a printhead comprising at least a first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

249. A printer according to claim 231, comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

250. A printer according to claim 231, comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

251. A printer according to claim 231, including at least one printhead module, configured for at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:
access a correction factor associated with the at least one printhead module;

determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

252. A printer according to claim 231, including a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

253. A printer according to claim 231, for controlling a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

254. A printer according to claim 231, including a printer controller for sending to a printhead:
dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;
the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.
255. A printer according to claim 231, including a printer controller for supplying data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.
256. A printer according to claim 231, including a printer controller for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:
a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;
wherein the printer controller is selectively configurable to supply dot data for the first and second modes.

257. A printer according to claim 231, including a printer controller for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

258. A printer according to claim 231, including a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:
a fire signal is provided to nozzles at a first and nth position in each set of nozzles;
a fire signal is provided to the next inward pair of nozzles in each set;
in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired; and in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

259. A printer according to claim 231, including a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

260. A printer according to claim 231, including a printer controller for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

261. A printer according to claim 231, including a printer controller for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

262. A printer according to claim 231, including a printer controller for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

263. A printer according to claim 231, including a printer controller for supplying data to a printhead module including:
at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

264. A printer according to claim 231, including a printer controller for supplying data to a printhead capable of printing a maximum of n of channels of print data, the printhead being configurable into:
a first mode, in which the printhead is configured to receive print data for a first number of the channels; and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

265. A printer according to claim 231, including a printer controller for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

266. A printer according to claim 231, including a printer controller for supplying data to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

267. A printer according to claim 231, including a printer controller for supplying data to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:
in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

268. A printer according to claim 231, including a printer controller for supplying data to a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

269. A printer according to claim 231, including a printer controller for supplying data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

270. A printer according to claim 231, including a printer controller for supplying data to a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

271. A printer according to claim 231, including a printer controller for supplying data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

272. A printer according to claim 231, including a printer controller for providing data to a printhead module that includes:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

273. A printer according to claim 231, including a printer controller for supplying data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

274. A printer according to claim 231, including a printer controller for supplying data to a printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

275. A printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

276. A printer according to claim 275, wherein the printhead modules are configured such that no dot data passes between them.

277. A printer according to claim 275, including at least one synchronization means between the first and second printer controllers for synchronizing the supply of dot data by the printer controllers.

278. A printer according to claim 275, wherein each of the printer controllers is configurable to supply the dot data to printhead modules of a plurality of different lengths.

279. A printer according to claim 275, wherein the printhead is a pagewidth printhead.

280. A print engine comprising:
a carrier;
a printhead comprising first and second elongate printhead modules, the printhead modules being mounted parallel to each other end to end on the carrier on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers mounted on the carrier and being configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

281. A print engine according to claim 280, wherein the printhead modules are configured such that no dot data passes between them.

282. A print engine according to claim 281, including at least one synchronization means between the first and second printer controllers for synchronizing the supply of dot by the printer controllers.

283. A print engine according to claim 281, wherein each of the printer controllers is configurable to supply the dot data to printhead modules of a plurality of different lengths.

284. A print engine according to claim 281, wherein the printhead is a pagewidth printhead.

285. A printer according to claim 275, for implementing a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier, the nozzles being disposed on the printhead module, the method comprising the steps of:
determining the rotational displacement;
determining at least one correction factor that at least partially compensates for the ink dot displacement; and using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

286. A printer according to claim 320 for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

287. A printer according to claim 275, for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:
(a) providing a fire signal to nozzles at a first and nth position in each set of nozzles;
(b) providing a fire signal to the next inward pair of nozzles in each set;

(c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and (d) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

288. A printer according to claim 275, manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.

289. A printer according to claim 275, including a printhead module including:
at least one row of print nozzles;
at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

290. A printer according to claim 275, comprising:
a printhead comprising at least a first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

291. A printer according to claim 275, comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

292. A printer according to claim 275, comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

293. A printer according to claim 275, including at least one printhead module, configured for at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:
access a correction factor associated with the at least one printhead module;
determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

294. A printer according to claim 275, including a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

295. A printer according to claim 275, for controlling a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

296. A printer according to claim 275, including a printer controller for sending to a printhead:
dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;
the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.

297. A printer according to claim 275, including a printer controller for supplying data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

298. A printer according to claim 275, including a printer controller for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:
a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;
wherein the printer controller is selectively configurable to supply dot data for the first and second modes.

299. A printer according to claim 275, including a printer controller for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

300. A printer according to claim 275, including a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:
a fire signal is provided to nozzles at a first and nth position in each set of nozzles;
a fire signal is provided to the next inward pair of nozzles in each set;
in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired; and in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

301. A printer according to claim 275, including a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

302. A printer according to claim 275, including a printer controller for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

303. A printer according to claim 275, including a printer controller for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

304. A printer according to claim 275, including a printer controller for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

305. A printer according to claim 275, including a printer controller for supplying data to a printhead module including:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

306. A printer according to claim 275, including a printer controller for supplying data to a printhead capable of printing a maximum of n of channels of print data, the printhead being configurable into:
a first mode, in which the printhead is configured to receive print data for a first number of the channels; and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

307. A printer according to claim 275, including a printer controller for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

308. A printer according to claim 275, including a printer controller for supplying data to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

309. A printer according to claim 275, including a printer controller for supplying data to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:
in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

310. A printer according to claim 275, including a printer controller for supplying data to a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

311. A printer according to claim 275, including a printer controller for supplying data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

312. A printer according to claim 275, including a printer controller for supplying data to a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

313. A printer according to claim 275, including a printer controller for supplying data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

314. A printer according to claim 275, including a printer controller for providing data to a printhead module that includes:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

315. A printer according to claim 275, including a printer controller for supplying data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

316. A printer according to claim 275, including a printer controller for supplying data to a printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

317. A printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

318. A printer according to claim 3 17, wherein the printhead modules are configured such that no dot data passes between them.

319. A printer according to claim 317, including at least one synchronization means between the first and second printer controllers for synchronizing the supply of dot data by the printer controllers.

320. A printer according to claim 317, wherein each of the printer controllers is configurable to supply the dot data to printhead modules of a plurality of different lengths.

321. A printer according to claim 317, wherein the printhead is a pagewidth printhead.

322. A print engine comprising:
a carrier;
a printhead comprising first and second elongate printhead modules, the printhead modules being mounted parallel to each other end to end on the carrier on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

323. A print engine according to claim 322, wherein the printhead modules are configured such that no dot data passes between them.

324. A print engine according to claim 323, including at least one synchronization means between the first and second printer controllers for synchronizing the supply of dot by the printer controllers.

325. A print engine according to claim 323, wherein each of the printer controllers is configurable to supply the dot data to printhead modules of a plurality of different lengths.

326. A print engine according to claim 323, wherein the printhead is a pagewidth printhead.

327. A printer controller according to claim 317, for implementing a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier, the nozzles being disposed on the printhead module, the method comprising the steps of:
determining the rotational displacement;
determining at least one correction factor that at least partially compensates for the ink dot displacement; and using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

328. A printer controller according to claim 362 for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

329. A printer controller according to claim 317, for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:
providing a fire signal to nozzles at a first and nth position in each set of nozzles;
providing a fire signal to the next inward pair of nozzles in each set;
in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

330. A printer controller according to claim 317, manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.

331. A printer controller according to claim 317, for supplying data to a printhead module including:
at least one row of print nozzles;
at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

332. A printer controller according to claim 317, installed in a printer comprising:
a printhead comprising at least a first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

333. A printer controller according to claim 317, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

334. A printer controller according to claim 317, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

335. A printer controller according to claim 317, for supplying dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:
access a correction factor associated with the at least one printhead module;
determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

336. A printer controller according to claim 317, for supplying dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

337. A printer controller according to claim 317, for controlling a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

338. A printer controller according to claim 317, for outputting to a printhead module:
dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;
the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.

339. A printer controller according to claim 317, for supplying data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

340. A printer controller according to claim 317, for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:
a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;
wherein the printer controller is selectively configurable to supply dot data for the first and second modes.

341. A printer controller according to claim 317, for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

342. A printer controller according to claim 317, for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:
a fire signal is provided to nozzles at a first and nth position in each set of nozzles;
a fire signal is provided to the next inward pair of nozzles in each set;
in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired; and in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

343. A printer controller according to claim 317, for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

344. A printer controller according to claim 317, for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

345. A printer controller according to claim 317, for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

346. A printer controller according to claim 317, for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

347. A printer controller according to claim 317, for supplying data to a printhead module including:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

348. A printer controller according to claim 317, for supplying data to a printhead capable of printing a maximum of n of channels of print data, the printhead being configurable into:
a first mode, in which the printhead is configured to receive print data for a first number of the channels; and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

349. A printer controller according to claim 317, for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

350. A printer controller according to claim 317, for supplying data to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

351. A printer controller according to claim 317, for supplying data to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:
in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

352. A printer controller according to claim 317, for supplying data to a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

353. A printer controller according to claim 317, for supplying data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

354. A printer controller according to claim 317, for supplying data to a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

355. A printer controller according to claim 317, for supplying data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

356. A printer controller according to claim 317, for providing data to a printhead module that includes:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

357. A printer controller according to claim 317, for supplying data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

358. A printer controller according to claim 317, for supplying data to a printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

359. A printer controller for supplying dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:
access a correction factor associated with the at least one printhead module;
determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

360. A printer controller according to claim 359, wherein the nozzles are disposed in a plurality of rows, and the printer controller is configured to reallocate at least one of the ink dots from at least one original print line to at least one alternate print line, thereby to effect the at least partial compensation.

361. A printer controller according to claim 359, configured to retrieve the correction factor from a memory associated with the printhead.

362. A printer controller according to claim 361, wherein the memory is mounted with the printhead, the printhead being mounted on the print engine.

363. A printer controller according to claim 359, wherein the rotational displacement is roll.

364. A printer controller according to claim 359, wherein the rotational displacement is yaw.

365. A printer controller according to claim 359, the printhead module being one of a plurality of printhead modules mounted on a carrier to form a printhead and the error in ink dot placement being an error relative to ink dots output by one or more of the other printhead modules.

366. A printer controller according to claim 359, wherein the printhead module is part of a printhead comprising a plurality of the modules, the printer controller being configured to determine an order in which at least some of the dot data is supplied to a plurality of the printhead modules, the order being determined at least partly on the basis of one or more of the correction factors, thereby to at least partially compensate for the rotational displacement of the plurality of the printheads.

367. A printer controller according to claim 359, wherein the correction factor is at least partially based on a thickness of media being printed on.

368. A printer controller according to claim 367, configured to at least improve first order continuity between ink dots printed by adjacent printhead modules.

369. A print engine including a print controller according to claim 404 and a plurality of the printhead modules that define a printhead, the print engine being configured to compensate for the rotational displacement of at least one of the printhead modules.

370. A print engine according to claim 4042, further including a memory for storing the correction factor in a form accessible to the printer controller.

371. A print engine according to claim 4042, configured to alter a timing of fire signals supplied to at least one of the nozzles on the basis of the correction factor, thereby to further effect the at least partial compensation.

372. A print engine according to claim 4044, configured to supply the altered fire signals are to both reallocated ink dots and non-reallocated ink dots.

373. A print engine according to claim 4042, wherein the printhead is a pagewidth printhead.

374. A printer including a print controller according to claim 404.

375. A printer according to claim 4045, further including a pagewidth printhead comprising a plurality of the printhead modules.

376. A printer controller according to claim 359, for implementing a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier, the nozzles being disposed on the printhead module, the method comprising the steps of:
determining the rotational displacement;
determining at least one correction factor that at least partially compensates for the ink dot displacement; and using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

377. A printer controller according to claim 404 for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

378. A printer controller according to claim 359, for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:
providing a fire signal to nozzles at a first and nth position in each set of nozzles;
providing a fire signal to the next inward pair of nozzles in each set;
in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

379. A printer controller according to claim 359, manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.
380. A printer controller according to claim 359, for supplying data to a printhead module including:
at least one row of print nozzles;
at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

381. A printer controller according to claim 359, installed in a printer comprising:
a printhead comprising at least a first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

382. A printer controller according to claim 359, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

383. A printer controller according to claim 359, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

384. A printer controller according to claim 359, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;

at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

385. A printer controller according to claim 359, for supplying dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

386. A printer controller according to claim 359, for controlling a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

387. A printer controller according to claim 359, for outputting to a printhead module:
dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;
the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.
388. A printer controller according to claim 359, for supplying data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

389. A printer controller according to claim 359, for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:
a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;
wherein the printer controller is selectively configurable to supply dot data for the first and second modes.

390. A printer controller according to claim 359, for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.
391. A printer controller according to claim 359, for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:
a fire signal is provided to nozzles at a first and nth position in each set of nozzles;
a fire signal is provided to the next inward pair of nozzles in each set;
in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired; and in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

392. A printer controller according to claim 359, printheadsupplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

393. A printer controller according to claim 359, for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

394. A printer controller according to claim 359, for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

395. A printer controller according to claim 359, for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

396. A printer controller according to claim 359, for supplying data to a printhead module including:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

397. A printer controller according to claim 359, for supplying data to a printhead capable of printing a maximum of n of channels of print data, the printhead being configurable into:
a first mode, in which the printhead is configured to receive print data for a first number of the channels; and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

398. A printer controller according to claim 359, for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.
399. A printer controller according to claim 359, for supplying data to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

400. A printer controller according to claim 359, for supplying data to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:
in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

401. A printer controller according to claim 359, for supplying data to a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

402. A printer controller according to claim 359, for supplying data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

403. A printer controller according to claim 359, for supplying data to a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

404. A printer controller according to claim 359, for supplying data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

405. A printer controller according to claim 359, for providing data to a printhead module that includes:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

406. A printer controller according to claim 359, for supplying data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

407. A printer controller according to claim 359, for supplying data to a printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

408. A printer controller for supplying dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

409. A printer controller according to claim 408, configured to modify the operation of the nozzles at or adjacent the at least one thermal sensor, such that operation of nozzles not at or adjacent the at least one thermal sensor is not modified.

410. A printer controller according to claim 409, wherein each thermal sensor is associated with a predetermined group of the nozzles, the printer controller being configured to modify operation of the nozzles in the predetermined group for which the temperature has risen above the first threshold.

411. A printer controller according to claim 410, wherein each thermal sensor is associated with a single nozzle.

412. A printer controller according to claim 411, wherein the modification includes the printer controller preventing operation of the nozzle.

413. A printer controller according to claim 412, wherein the modification includes the printer controller preventing operation of the nozzle for a predetermined period.

414. A printer controller according to claim 412, wherein the modification includes the printer controller preventing operation of the nozzle until the temperature drops below a second threshold.

415. A printer controller according to claim 414, wherein the second threshold is lower than the first threshold.

461. A printer controller according to claim 415, wherein the second threshold is the same as the first threshold.

417. A printer controller according to claim 408, wherein the temperature is not determined explicitly by the at least one thermal sensor or the module.

418. A printer controller according to claim 408, wherein each of the nozzles including a thermal ink ejection mechanism.

419. A printer controller according to claim 418, wherein the thermal sensor comprises at least part of one of the thermal inkjet mechanisms.

420. A printer controller according to claim 419, wherein the thermal sensor comprises a heating element.
421. A printer controller according to claim 420, wherein the thermal sensor determines the temperature by determining a resistance of the heating element.

422. A printer controller according to claim 408, configured to:
receive thermal information from the at least one thermal sensor;
determine the modification based on the thermal information; and send control information back to the printhead module, the control information being indicative of the modification to make to the operation of the one or more nozzles.

423. A print engine including a printer controller according to claim 467 and the printhead module, wherein the printhead module further includes a plurality of data latches, the data latches being configured to provide dot data to respective ones of the nozzles, at least some of the data latches being configured to receive thermal signals from respective ones of the thermal sensors during an acquisition period.

424. A print engine according to claim 423, wherein the data latches are configured to form a shift register, the shift register being configured to:
shift the print data in during a print load phase;
sample the signals from the thermal sensors during a temperature load phase;
and shift the thermal signals out to the printer controller during an output phase.

425. A print engine according to claim 424, wherein the output phase coincides with a subsequent print load phase.

426. A print engine according to claim 425, further including logic circuitry configured to perform a bitwise operation on: each thermal signal as it is clocked out of the shift register;
and each piece of dot data to be clocked into the shift register, such that when a thermal signal is indicative of a thermal problem with a nozzle, the logic circuitry prevents loading of data that would cause firing of that nozzle.

427. A print engine according to claim 426, wherein the logic circuitry includes an AND circuit that receives as inputs the dot data and the thermal signal corresponding to the nozzle for which the dot data is intended, an output of the AND circuit being in communication with an input of the shift register.

428. A printer controller according to claim 408, wherein each thermal sensor is associated with a pair of the nozzles.

429. A printer controller according to claim 408, for implementing a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier, the nozzles being disposed on the printhead module, the method comprising the steps of:
determining the rotational displacement;
determining at least one correction factor that at least partially compensates for the ink dot displacement; and using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

430. A printer controller according to claim 453 for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

431. A printer controller according to claim 408, for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:
(a) providing a fire signal to nozzles at a first and nth position in each set of nozzles;
(b) providing a fire signal to the next inward pair of nozzles in each set;
(c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and (d) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

432. A printer controller according to claim 408, manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.

433. A printer controller according to claim 408, for supplying data to a printhead module including:
at least one row of print nozzles;
at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

434. A printer controller according to claim 408, installed in a printer comprising:
a printhead comprising at least a first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

435. A printer controller according to claim 408, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

436. A printer controller according to claim 408, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

437. A printer controller according to claim 408, installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

438. A printer controller according to claim 408, for supplying dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:
access a correction factor associated with the at least one printhead module;
determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

439. A printer controller according to claim 408, for controlling a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

440. A printer controller according to claim 408, for outputting to a printhead module:
dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;
the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.

441. A printer controller according to claim 408, for supplying data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

442. A printer controller according to claim 408, for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:
a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;
wherein the printer controller is selectively configurable to supply dot data for the first and second modes.

443. A printer controller according to claim 408, for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.
444. A printer controller according to claim 408, for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:
a fire signal is provided to nozzles at a first and nth position in each set of nozzles;
a fire signal is provided to the next inward pair of nozzles in each set;
in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired; and in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

445. A printer controller according to claim 408, for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

446. A printer controller according to claim 408, for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

447. A printer controller according to claim 408, for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

448. A printer controller according to claim 408, for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

449. A printer controller according to claim 408, for supplying data to a printhead module including:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

450. A printer controller according to claim 408, for supplying data to a printhead capable of printing a maximum of n of channels of print data, the printhead being configurable into:
a first mode, in which the printhead is configured to receive print data for a first number of the channels; and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

451. A printer controller according to claim 408, for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

452. A printer controller according to claim 408, for supplying data to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

453. A printer controller according to claim 408, for supplying data to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:
in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

454. A printer controller according to claim 408, for supplying data to a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

455. A printer controller according to claim 408, for supplying data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

456. A printer controller according to claim 408, for supplying data to a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

457. A printer controller according to claim 408, for supplying data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

458. A printer controller according to claim 408, for providing data to a printhead module that includes:
at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

459. A printer controller according to claim 408, for supplying data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

460. A printer controller according to claim 408, for supplying data to a printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

461. A printer controller according to claim 427, further including a logic circuit accepting as inputs a masking signal and the thermal signal corresponding to the nozzle for which the dot data is intended, the logic circuit outputting the thermal signal to the input of the AND circuit in reliance on a value of the masking signal.
462. A printer controller according to claim 461, wherein the value of the masking signal enables masking of the thermal signal for at least one nozzle position, including the nozzle for which the current dot data is intended.
463. A printer controller according to claim 461, wherein the value of the masking signal enables masking of the thermal signal for a plurality of nozzle positions corresponding to a region of the printhead associated the nozzle for which the current dot data is intended.

464. A printer controller according to claim 461, wherein the value of the masking signal enables masking of the thermal signal for all of the nozzle positions of the printhead.

465. A printer controller for controlling a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

466. A printer controller according to claim 465, wherein the one or more control signals include a fire control sequence indicative of a first fire group to be fired.

467. A printer controller according to claim 466, the printhead being configured to shift the fire control sequence through a shift register to cause subsequent firing of the second and any other fire groups, wherein the printer controller is configured to provide the fire control sequence during an initiation phase of the printhead, such that the fire control sequence does not need to be repeatedly provided by the printer controller while printing is taking place.

468. A printer controller according to claim 466, the printhead being configured to shift the fire control sequence through a shift register to cause subsequent firing of the second and any other fire groups, wherein the printer controller is configured to provide the fire control sequence periodically during printing.

469. A printer controller according to claim 468, configured to provide the fire control sequence on a per row or per print-line basis.

470. A printer controller according to claim 465, configured to provide a fire enable signal in addition to the one or more fire control signals, such that the combination of the fire enable and fire control signals cause selected ones of the nozzles to fire in the predetermined sequence and in accordance with a predetermined timing.

471. A print engine including a printhead and a printer controller, the printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

472. A print engine according to claim 471, wherein the one or more control signals include a fire control sequence indicative of a first fire group to be fired.

473. A print engine according to claim 472, the printhead being configured to shift the fire control sequence through a shift register to cause subsequent firing of the second and any other fire groups, wherein the printer controller is configured to provide the fire control sequence during an initiation phase of the printhead, such that the fire control sequence does not need to be repeatedly provided by the printer controller while printing is taking place.

474. A print engine according to claim 472, the printhead being configured to shift the fire control sequence through a shift register to cause subsequent firing of the second and any other fire groups, wherein the printer controller is configured to provide the fire control sequence periodically during printing.

475. A print engine according to claim 468, configured to provide the fire control sequence on a per row or per print-line basis.

476. A print engine according to claim 465, configured to provide a fire enable signal in addition to the one or more fire control signals, such that the combination of the fire enable and fire control signals cause selected ones of the nozzles to fire in the predetermined sequence and in accordance with a predetermined timing.

477. A printer controller according to claim 465, for implementing a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier, the nozzles being disposed on the printhead module, the method comprising the steps of:
determining the rotational displacement;
determining at least one correction factor that at least partially compensates for the ink dot displacement; and using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

478. A printer controller according to claim 510 for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

479. A printer controller according to claim 465, for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:
providing a fire signal to nozzles at a first and nth position in each set of nozzles;

providing a fire signal to the next inward pair of nozzles in each set;
in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

480. A printer controller according to claim 465, manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.
481. A printer controller according to claim 465, for supplying data to a printhead module including:
at least one row of print nozzles;
at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

482. A printer controller according to claim 465, installed in a printer comprising:
a printhead comprising at least a first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

483. A printer controller according to claim 465, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

484. A printer controller according to claim 465, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

485. A printer controller according to claim 465, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

486. A printer controller according to claim 465, for supplying dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:
access a correction factor associated with the at least one printhead module;
determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

487. A printer controller according to claim 465, for supplying dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

488. A printer controller according to claim 465, for outputting to a printhead module:
dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;
the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.

489. A printer controller according to claim 465, for supplying data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

490. A printer controller according to claim 465, for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:
a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;
wherein the printer controller is selectively configurable to supply dot data for the first and second modes.

491. A printer controller according to claim 465, for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.
492. A printer controller according to claim 465, for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:
(a) a fire signal is provided to nozzles at a first and nth position in each set of nozzles;
(b) a fire signal is provided to the next inward pair of nozzles in each set;
(c) in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired;
and (d) in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

493. A printer controller according to claim 465, for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

494. A printer controller according to claim 465, for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

495. A printer controller according to claim 465, for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

496. A printer controller according to claim 465, for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

497. A printer controller according to claim 465, for supplying data to a printhead module including:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

498. A printer controller according to claim 465, for supplying data to a printhead capable of printing a maximum of n of channels of print data, the printhead being configurable into:
a first mode, in which the printhead is configured to receive print data for a first number of the channels; and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

499. A printer controller according to claim 465, for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.
500. A printer controller according to claim 465, for supplying data to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

501. A printer controller according to claim 465, for supplying data to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:
in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

502. A printer controller according to claim 465, for supplying data to a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

503. A printer controller according to claim 465, for supplying data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

504. A printer controller according to claim 465, for supplying data to a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

505. A printer controller according to claim 465, for supplying data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

506. A printer controller according to claim 465, for providing data to a printhead module that includes:
at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

507. A printer controller according to claim 465, for supplying data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

508. A printer controller according to claim 465, for supplying data to a printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

509. A printer controller according to claim 465, wherein the printhead module includes a plurality of pairs of the rows, each pair of rows including an odd row and an even row, the odd and even rows in each pair being offset from each other in both x and y directions relative to an intended direction of print media movement relative to the printhead, the printer controller being configured to control the at least one printhead module to cause firing of at least a plurality of the odd rows prior to firing any of the even rows, or vice versa.

510. A printer controller according to claim 509, wherein all the odd rows are fired before any of the even rows are fired, or vice versa.

511. A printer controller according to claim 509, configured to control the printhead module such that the odd rows, or the even rows, or both, are fired in a predetermined order.

512. A printer controller according to claim 511, configurable such that the predetermined order is selectable from a plurality of predetermined available orders.

513. A printer controller according to claim 509, wherein the predetermined order is sequential.

514. A printer controller according to claim 513, configurable such that the predetermined order can commence at any of a plurality of the rows.

515. A printer controller for outputting to a printhead module:
dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;
the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.

516. A printer controller according to claim 515, wherein the communication output is configured to output the dot data and control data serially.

517. A printer controller according to claim 515, further including a plurality of the communication outputs.

518. A printer controller according to claim 516, further including a plurality of the communication outputs.

519. A print engine comprising a print controller according to claim 560 and a plurality of printhead modules, the printhead modules being disposed end to end for printing a width exceeding that of any of the individual printhead modules, the communications input of each of the printhead modules being connected to a common dot data and control data bus, the common dot data and control data bus being in functional communication with the communication output.

520. A print engine according to claim 519, wherein each module is configured to respond to dot data and control data on the bus only when it is intended for that module.

521. A printer incorporating a print engine according to claim 564.

522. A printer incorporating a print controller according to claim 560.

523. A print engine according to claim 519, wherein the printhead modules together form a pagewidth printhead.

524. A printer according to claim 522, further including a pagewidth printhead comprising a plurality of the printhead modules.

525. A printer controller according to claim 515, for implementing a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier, the nozzles being disposed on the printhead module, the method comprising the steps of:
determining the rotational displacement;

determining at least one correction factor that at least partially compensates for the ink dot displacement; and using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

526. A printer controller according to claim 560 for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

527. A printer controller according to claim 515, for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:
providing a fire signal to nozzles at a first and nth position in each set of nozzles;
providing a fire signal to the next inward pair of nozzles in each set;
in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

528. A printer controller according to claim 515, manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.

529. A printer controller according to claim 515, for supplying data to a printhead module including:
at least one row of print nozzles;
at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

530. A printer controller according to claim 515, installed in a printer comprising:
a printhead comprising at least a first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

531. A printer controller according to claim 515, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

532. A printer controller according to claim 515, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

533. A printer controller according to claim 515, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

534. A printer controller according to claim 515, for supplying dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:
access a correction factor associated with the at least one printhead module;
determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

535. A printer controller according to claim 515, for supplying dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

536. A printer controller according to claim 515, for controlling a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

537. A printer controller according to claim 515, for supplying data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

538. A printer controller according to claim 515, for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:
a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;
wherein the printer controller is selectively configurable to supply dot data for the first and second modes.

539. A printer controller according to claim 515, for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

540. A printer controller according to claim 515, for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:
(a) a fire signal is provided to nozzles at a first and nth position in each set of nozzles;
(b) a fire signal is provided to the next inward pair of nozzles in each set;

(c) in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired;
and (d) in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

541. A printer controller according to claim 515, for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

542. A printer controller according to claim 515, for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

543. A printer controller according to claim 515, for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

544. A printer controller according to claim 515, for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

545. A printer controller according to claim 515, for supplying data to a printhead module including:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

546. A printer controller according to claim 515, for supplying data to a printhead capable of printing a maximum of n of channels of print data, the printhead being configurable into:
a first mode, in which the printhead is configured to receive print data for a first number of the channels; and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

547. A printer controller according to claim 515, for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

548. A printer controller according to claim 515, for supplying data to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

549. A printer controller according to claim 515, for supplying data to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:
in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

550. A printer controller according to claim 515, for supplying data to a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

551. A printer controller according to claim 515, for supplying data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

552. A printer controller according to claim 515, for supplying data to a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

553. A printer controller according to claim 515, for supplying data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

554. A printer controller according to claim 515, for providing data to a printhead module that includes:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

555. A printer controller according to claim 515, for supplying data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

556. A printer controller according to claim 515, for supplying data to a printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

557. A printer controller for supplying data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed, the printer controller being configured to control order and timing of the data supplied to the printhead such that the dropped row is compensated for during printing by the printhead module.

558. A printer controller according to claim 557, wherein the displaced row portion is disposed adjacent one end of the printhead module.

559. A printer controller according to claim 557, wherein the printhead module includes a plurality of the rows, wherein each of at least a plurality of the rows includes one of the displaced row portions.

560. A printer controller according to claim 559, wherein the displaced row portions of at least some of the rows are different in length than the displaced row portions of at least some of the other rows.

561. A printer controller according to claim 560, wherein each of the rows has a displaced row portion, and the sizes of the respective displaced row portions increase from row to row in the direction normal to that of the pagewidth to be printed.

562. A printer controller according to claim 557, for supplying supplying the data to a printhead comprising a plurality of the printhead modules.

563. A printer controller according to claim 602 for supplying data to a printhead comprising a plurality of the printhead modules, wherein the displaced row portion of at least one of the printhead modules is disposed adjacent another of the printhead modules.

564. A printer controller according to claim 563, wherein the printhead modules are the same shape and configuration as each other, and are arranged end to end across the intended print width.

565. A printer controller according to claim 563, the printhead being a pagewidth printhead.

566. A printer controller according to claim 564, the printhead being a pagewidth printhead.

567. A printer controller according to claim 557, for implementing a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier, the nozzles being disposed on the printhead module, the method comprising the steps of:
determining the rotational displacement;
determining at least one correction factor that at least partially compensates for the ink dot displacement; and using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

568. A printer controller according to claim 602 for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

569. A printer controller according to claim 557, for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:
providing a fire signal to nozzles at a first and nth position in each set of nozzles;
providing a fire signal to the next inward pair of nozzles in each set;
in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

570. A printer controller according to claim 557, manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.
571. A printer controller according to claim 557, for supplying data to a printhead module including:
at least one row of print nozzles;
at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

572. A printer controller according to claim 557, installed in a printer comprising:
a printhead comprising at least a first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

573. A printer controller according to claim 557, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being; parallel to each other and being disposed end to end on either side of a join region;

at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

574. A printer controller according to claim 557, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

575. A printer controller according to claim 557, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

576. printer controller according to claim 557, for supplying dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:
access a correction factor associated with the at least one printhead module;
determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

577. A printer controller according to claim 557, for supplying dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

578. A printer controller according to claim 557, for controlling a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

579. A printer controller according to claim 557, for outputting to a printhead module:
dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;
the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.
580. A printer controller according to claim 557, for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:
a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;
wherein the printer controller is selectively configurable to supply dot data for the first and second modes.

581. A printer controller according to claim 557, for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.
582. A printer controller according to claim 557, for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:
(a) a fire signal is provided to nozzles at a first and nth position in each set of nozzles;
(b) a fire signal is provided to the next inward pair of nozzles in each set;

(c) in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired;
and (d) in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

583. A printer controller according to claim 557, for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

584. A printer controller according to claim 557, for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

585. A printer controller according to claim 557, for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

586. A printer controller according to claim 557, for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

587. A printer controller according to claim 557, for supplying data to a printhead module including:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

588. A printer controller according to claim 557, for supplying data to a printhead capable of printing a maximum of n of channels of print data, the printhead being configurable into:
a first mode, in which the printhead is configured to receive print data for a first number of the channels; and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

589. A printer controller according to claim 557, for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.
590. A printer controller according to claim 557, for supplying data to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

591. A printer controller according to claim 557, for supplying data to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:
in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

592. A printer controller according to claim 557, for supplying data to a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

593. A printer controller according to claim 557, for supplying data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

594. A printer controller according to claim 557, for supplying data to a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

595. A printer controller according to claim 557, for supplying data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.
596. A printer controller according to claim 557, for providing data to a printhead module that includes:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

597. A printer controller according to claim 557, for supplying data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

598. A printer controller according to claim 557, for supplying data to a printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

599. A printer controller for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:
a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;
wherein the printer controller is selectively configurable to supply dot data for the first and second modes.

600. A printer controller according to claim 599, wherein the first number is n.

601. A printer controller according to claim 599, wherein the first number is less than n.

602. A printer controller according to claim 599, wherein the printhead module being configurable into at least one other mode, in which the at least one printhead module is configured to receive print data for a third number of print channels other than the first and second numbers, the printer controller being selectively configurable to supply the print data for the third number of print channels.

603. A printer controller according to claim 599, wherein n is 4 and the second number is less than 4.
604. A printer controller according to claim 599, wherein n is 5 and the second number is less than 5.
605. A printer controller according to claim 599, wherein n is 6 and the second number is less than 6.
606. A printer controller according to claim 605, wherein the second number is 3, 4 or 5.

607. A print engine including the print controller according to claim 644 and the at least one printhead module.

608. A print engine according to claim 607, wherein the mode is selected based on the contents of a memory associated with the at least one printhead module.

609. A printhead according to claim 607, wherein the memory is a register.

610. A printhead according to claim 607, wherein the register is on an integrated circuit forming part of the print engine.

611. A printer including a printer controller according to claim 644.
612. A printer including a print engine according to claim 652.

613. A printer according to claim 611, including a pagewidth printhead comprising a plurality of the printhead modules of claim 1.

614. A printer controller according to claim 599, for implementing a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier, the nozzles being disposed on the printhead module, the method comprising the steps of:
determining the rotational displacement;
determining at least one correction factor that at least partially compensates for the ink dot displacement; and using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

615. A printer controller according to claim 644 for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

616. A printer controller according to claim 599, for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:
providing a fire signal to nozzles at a first and nth position in each set of nozzles;
providing a fire signal to the next inward pair of nozzles in each set;
in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

617. A printer controller according to claim 599, manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.
618. A printer controller according to claim 599, for supplying data to a printhead module including:
at least one row of print nozzles;
at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

619. A printer controller according to claim 599, installed in a printer comprising:

a printhead comprising at least a first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

620. A printer controller according to claim 599, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

621. A printer controller according to claim 599, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

622. A printer controller according to claim 599, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

623. A printer controller according to claim 599, for supplying dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:

access a correction factor associated with the at least one printhead module;
determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

624. A printer controller according to claim 599, for supplying dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

625. A printer controller according to claim 599, for controlling a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

626. A printer controller according to claim 599, for outputting to a printhead module:
dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;
the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.
627. A printer controller according to claim 599, for supplying data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

628. A printer controller according to claim 599, for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

629. A printer controller according to claim 599, for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:
a fire signal is provided to nozzles at a first and nth position in each set of nozzles;
a fire signal is provided to the next inward pair of nozzles in each set;
in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired; and in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

630. A printer controller according to claim 599, for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

631. A printer controller according to claim 599, for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

632. A printer controller according to claim 599, for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

633. A printer controller according to claim 599, for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

679. A printer controller according to claim 599, for supplying data to a printhead module including:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

635. A printer controller according to claim 599, for supplying data to a printhead capable of printing a maximum of n of channels of print data, the printhead being configurable into:
a first mode, in which the printhead is configured to receive print data for a first number of the channels; and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

636. A printer controller according to claim 599, for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

637. A printer controller according to claim 599, for supplying data to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

638. A printer controller according to claim 599, for supplying data to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:
in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

639. A printer controller according to claim 599, for supplying data to a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

640. A printer controller according to claim 599, for supplying data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

641. A printer controller according to claim 599, for supplying data to a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

642. A printer controller according to claim 599, for supplying data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

643. A printer controller according to claim 599, for providing data to a printhead module that includes:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

644. A printer controller according to claim 599, for supplying data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

645. A printer controller according to claim 599, for supplying data to a printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

646. A printer controller for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

647. A printer controller according to claim 646, wherein the printhead comprises a plurality of at least one of the types of module.

648. A printer controller according to claim 647, wherein the printhead comprises a plurality of each of at least two of the types of module.

649. A printer controller according to claim 646, wherein the printhead comprises two types of the module.

650. A printer controller according to claim 649, wherein the two types of module alternate across a print width of the printhead.

651. A printer controller according to claim 646, each of the modules including at least one row of print nozzles, wherein each of the at least one row of print nozzles includes at least a portion that extends at an acute angle to an intended relative direction of movement between the printhead and print media.

652. A printer controller according to claim 651, wherein the different types of modules are configured, and arranged relative to each other, such that there is substantially no growth in offset of each of the at least one row of print nozzles in a direction across an intended print width of the printhead.

653. A printer controller according to claim 646, wherein each of the printhead modules is a monolithic integrated circuit.

654. A printer controller according to claim 646, each of the modules including at least one row of print nozzles, wherein each of the at least one rows includes at least two sub-rows, each of the sub-rows being parallel to each other and displaced relative to each other in a direction of intended movement of print media relative to the printhead.

655. A printer controller according to claim 646, wherein at least one row in each of the printhead modules prints an ink corresponding to at least one row on an adjacent printhead module, wherein the corresponding rows of at least two of the different printhead modules are offset from each other in a direction of intended movement of print media relative to the printhead, 656. A printer controller according to claim 646, the printhead being a pagewidth printhead.

657. A printer controller according to claim 652, the printhead being a pagewidth printhead.

658. A printer controller according to claim 657, the printhead being a pagewidth printhead.

659. A printer controller according to claim 646, for implementing a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier, the nozzles being disposed on the printhead module, the method comprising the steps of:
determining the rotational displacement;
determining at least one correction factor that at least partially compensates for the ink dot displacement; and using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

660. A printer controller according to claim 691 for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

661. A printer controller according to claim 646, for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:
providing a fire signal to nozzles at a first and nth position in each set of nozzles;
providing a fire signal to the next inward pair of nozzles in each set;
in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

662. A printer controller according to claim 646, manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.

663. A printer controller according to claim 646, for supplying data to a printhead module including:
at least one row of print nozzles;
at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

664. A printer controller according to claim 646, installed in a printer comprising:
a printhead comprising at least a first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

665. A printer controller according to claim 646, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

666. A printer controller according to claim 646, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

667. A printer controller according to claim 646, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

668. A printer controller according to claim 646, for supplying dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:
access a correction factor associated with the at least one printhead module;
determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

669. A printer controller according to claim 646, for supplying dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

670. A printer controller according to claim 646, for controlling a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

671. A printer controller according to claim 646, for outputting to a printhead module:
dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;
the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.

672. A printer controller according to claim 646, for supplying data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

673. A printer controller according to claim 646, for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:
a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;
wherein the printer controller is selectively configurable to supply dot data for the first and second modes.

674. A printer controller according to claim 646, for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:
a fire signal is provided to nozzles at a first and nth position in each set of nozzles;
a fire signal is provided to the next inward pair of nozzles in each set;
in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired; and in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

675. A printer controller according to claim 646, for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

676. A printer controller according to claim 646, for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

677. A printer controller according to claim 646, for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

678. A printer controller according to claim 646, for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

679. A printer controller according to claim 646, for supplying data to a printhead module including:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

680. A printer controller according to claim 646, for supplying data to a printhead capable of printing a maximum of n of channels of print data, the printhead being configurable into:
a first mode, in which the printhead is configured to receive print data for a first number of the channels; and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

681. A printer controller according to claim 646, for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

682. A printer controller according to claim 646, for supplying data to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

683. A printer controller according to claim 646, for supplying data to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:
in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

684. A printer controller according to claim 646, for supplying data to a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

685. A printer controller according to claim 646, for supplying data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

686. A printer controller according to claim 646, for supplying data to a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

687. A printer controller according to claim 646, for supplying data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

688. A printer controller according to claim 646, for providing data to a printhead module that includes:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

689. A printer controller according to claim 646, for supplying data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

690. A printer controller according to claim 646, for supplying data to a printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

691. A printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:
a fire signal is provided to nozzles at a first and nth position in each set of nozzles;
a fire signal is provided to the next inward pair of nozzles in each set;
in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired; and in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

692. A printer controller according to claim 691, wherein the printhead module includes a plurality of the rows of nozzles, the printer controller being configured to control the printhead module such that steps (a) to (d) are repeated for each of the rows of nozzles.

693. A printer controller according to claim 692, wherein the rows are disposed in pairs.

694. A printer controller according to claim 693, wherein the rows in each pair of rows are offset relative to each other.

695. A printer controller according to claim 694, wherein each pair of rows is configured to print the same color ink.

696. A printer controller according to claim 695, wherein each pair of rows is connected to a common ink source.

697. A printer controller according to claim 691, wherein the sets of nozzles are adjacent each other.

698. A printer controller according to claim 691, wherein the sets of nozzles are separated by an intermediate nozzle, the intermediate nozzle being fired either prior to the nozzle at position I in each set, or following the nozzle at position n.

699. A printer controller according to claim 691, wherein the printhead module is one of a plurality of printhead modules that form a pagewidth printhead, the printer controller being configure to supply the control signals to at least a plurality of the printhead modules.

700. A printer controller according to claim 691, for implementing a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier, the nozzles being disposed on the printhead module, the method comprising the steps of:
determining the rotational displacement;
determining at least one correction factor that at least partially compensates for the ink dot displacement; and using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

701. A printer controller according to claim 736 for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

702. A printer controller according to claim 691, for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:
(a) providing a fire signal to nozzles at a first and nth position in each set of nozzles;
(b) providing a fire signal to the next inward pair of nozzles in each set;
(c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and (d) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

748. A printer controller according to claim 691, manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.

704. A printer controller according to claim 691, for supplying data to a printhead module including:
at least one row of print nozzles;
at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

705. A printer controller according to claim 691, installed in a printer comprising:
a printhead comprising at least a first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

706. A printer controller according to claim 691, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

707. A printer controller according to claim 691, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

708. A printer controller according to claim 691, installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

709. A printer controller according to claim 691, for supplying dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:
access a correction factor associated with the at least one printhead module;
determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

710. A printer controller according to claim 691, for supplying dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

711. A printer controller according to claim 691, for controlling a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

712. A printer controller according to claim 691, for outputting to a printhead module:
dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;
the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.

713. A printer controller according to claim 691, for supplying data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

714. A printer controller according to claim 691, for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:
a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;
wherein the printer controller is selectively configurable to supply dot data for the first and second modes.

715. A printer controller according to claim 691, for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

716. A printer controller according to claim 691, for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

717. A printer controller according to claim 691, for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

718. A printer controller according to claim 691, for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

719. A printer controller according to claim 691, for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

720. A printer controller according to claim 691, for supplying data to a printhead module including:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

721. A printer controller according to claim 691, for supplying data to a printhead capable of printing a maximum of n of channels of print data, the printhead being configurable into:
a first mode, in which the printhead is configured to receive print data for a first number of the channels; and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

722. A printer controller according to claim 691, for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

723. A printer controller according to claim 691, for supplying data to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

724. A printer controller according to claim 691, for supplying data to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:
in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

725. A printer controller according to claim 691, for supplying data to a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

726. A printer controller according to claim 691, for supplying data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

727. A printer controller according to claim 691, for supplying data to a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

728. A printer controller according to claim 691, for supplying data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

729. A printer controller according to claim 691, for providing data to a printhead module that includes:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

730. A printer controller according to claim 691, for supplying data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

731. A printer controller according to claim 691, for supplying data to a printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

732. A printer controller according to claim 691, wherein the printhead module includes a plurality of the rows, the printer controller being configured to cause firing of each nozzle in each row simultaneously with the nozzle or nozzles at the same position in the other rows.

733. A printer controller according to claim 691, including a plurality of pairs of the rows, each pair of rows including an odd row and an even row, the odd and even rows in each pair being offset from each other in both x and y directions relative to an intended direction of print media movement relative to the printhead, the printer controller being configured to control the at least one printhead module to cause firing of at least a plurality of the odd rows prior to firing any of the even rows, or vice versa.

734. A printer controller according to claim 733, wherein all the odd rows are fired before any of the even rows are fired, or vice versa.

735. A printer controller according to claim 733, configured to control the printhead such that the odd rows, or the even rows, or both, are fired in a predetermined order.

736. A printer controller according to claim 735, configurable such that the predetermined order is selectable from a plurality of predetermined available orders.

737. A printer controller according to claim 733, wherein the predetermined order is sequential.

738. A printer controller according to claim 737, configurable such that the predetermined order can commence at any of a plurality of the rows.

739. A printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

740. A printer controller according to claim 739, configured to cause the nozzle at each given position within the set to be fired simultaneously with the nozzles in the other sets at respective corresponding positions.

741. A printer controller according to claim 739, wherein the printhead module includes a plurality of the rows of nozzles, the printer controller being configured to control the printhead module such that the steps are repeated for each of the rows of nozzles.

742. A printer controller according to claim 741, wherein the rows are disposed in pairs.

743. A printer controller according to claim 742, wherein the rows in each pair of rows are offset relative to each other.

744. A printer controller according to claim 743, wherein each pair of rows is configured to print the same color ink.

745. A printer controller according to claim 744, wherein each pair of rows is connected to a common ink source.

746. A printer controller according to claim 739, wherein the sets of nozzles are adjacent each other.

747. A printer controller according to claim 739, wherein the sets of nozzles are separated by an intermediate nozzle, the intermediate nozzle being fired either prior to the nozzle at position 1 in each set, or following the nozzle at position n.

748. A printer controller according to claim 739, wherein the printhead module is one of a plurality of printhead modules that form a pagewidth printhead, the printer controller being configure to supply the control signals to at least a plurality of the printhead modules.

749. A printer controller according to claim 739, for implementing a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier, the nozzles being disposed on the printhead module, the method comprising the steps of:
determining the rotational displacement;

determining at least one correction factor that at least partially compensates for the ink dot displacement; and using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

750. A printer controller according to claim 784 for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

751. A printer controller according to claim 739, for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:
providing a fire signal to nozzles at a first and nth position in each set of nozzles;
providing a fire signal to the next inward pair of nozzles in each set;
in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

752. A printer controller according to claim 739, manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.
753. A printer controller according to claim 739, for supplying data to a printhead module including:
at least one row of print nozzles;
at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

754. A printer controller according to claim 739, installed in a printer comprising:
a printhead comprising at least a first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

755. A printer controller according to claim 739, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

756. A printer controller according to claim 739, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

757. A printer controller according to claim 739, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

758. A printer controller according to claim 739, for supplying dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:
access a correction factor associated with the at least one printhead module;
determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

759. A printer controller according to claim 739, for supplying dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

760. A printer controller according to claim 739, for controlling a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

761. A printer controller according to claim 739, for outputting to a printhead module:
dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;
the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.
762. A printer controller according to claim 739, for supplying data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

763. A printer controller according to claim 739, for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:
a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;
wherein the printer controller is selectively configurable to supply dot data for the first and second modes.

764. A printer controller according to claim 739, for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

765. A printer controller according to claim 739, for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:
a fire signal is provided to nozzles at a first and nth position in each set of nozzles;
a fire signal is provided to the next inward pair of nozzles in each set;
in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired; and in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

766. A printer controller according to claim 739, for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

767. A printer controller according to claim 739, for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

768. A printer controller according to claim 739, for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

769. A printer controller according to claim 739, for supplying data to a printhead module including:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

770. A printer controller according to claim 739, for supplying data to a printhead capable of printing a maximum of n of channels of print data, the printhead being configurable into:
a first mode, in which the printhead is configured to receive print data for a first number of the channels; and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

771. A printer controller according to claim 739, for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.
772. A printer controller according to claim 739, for supplying data to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

773. A printer controller according to claim 739, for supplying data to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:
in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

774. A printer controller according to claim 739, for supplying data to a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

775. A printer controller according to claim 739, for supplying data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

776. A printer controller according to claim 739, for supplying data to a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

777. A printer controller according to claim 739, for supplying data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

778. A printer controller according to claim 739, for providing data to a printhead module that includes:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

779. A printer controller according to claim 739, for supplying data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

780. A printer controller according to claim 739, for supplying data to a printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

781. A printer controller according to claim 739, wherein the printhead module includes a plurality of the rows, the printer controller being configured to cause firing of each nozzle in each row simultaneously with the nozzle or nozzles at the same position in the other rows.

782. A printer controller according to claim 739, including a plurality of pairs of the rows, each pair of rows including an odd row and an even row, the odd and even rows in each pair being offset from each other in both x and y directions relative to an intended direction of print media movement relative to the printhead, the printer controller being configured to control the at least one printhead module to cause firing of at least a plurality of the odd rows prior to firing any of the even rows, or vice versa.

783. A printer controller according to claim 827 wherein all the odd rows are fired before any of the even rows are fired, or vice versa.

784. A printer controller according to claim 827 configured to control the printhead such that the odd rows, or the even rows, or both, are fired in a predetermined order.

785. A printer controller according to claim 784, configurable such that the predetermined order is selectable from a plurality of predetermined available orders.

786. A printer controller according to claim 827 wherein the predetermined order is sequential.

787. A printer controller according to claim 786, configurable such that the predetermined order can commence at any of a plurality of the rows.

788. A printer controller for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

789. A print engine comprising a printer controller according to claim 833 and the printhead module, wherein the printhead module is controllable such that either of the nozzles in each aligned pair of nozzles in the first and second rows can be selected to output ink for a selected dot to be printed on the print media.

790. A print engine according to claim 789, wherein, in the event a nozzle in the first row is faulty, the corresponding nozzle in the second row is selected to output ink for a dot for which the faulty nozzle would otherwise have output ink.

791. A print engine according to claim 789, including a plurality of sets of the first and second rows.

792. A print engine according to claim 791, wherein each of the sets of the first and second rows is configured to print in a single color or ink type.

793. A print engine according to claim 792, wherein the first and second rows in at least one of the sets are separated by one or more rows from the other set or sets.

794. A print engine according to claim 788, wherein each of the rows includes an odd sub-row and an even sub-row, the odd and even sub-rows being offset with respect to each other in a direction of intended print media travel relative to the printhead.

795. A print engine according to claim 794, wherein the odd and even sub-rows are transversely offset relative to each other.

796. A print engine according to claim 789, configured such that the first and second rows are fired alternately.

797. A print engine according to claim 789, comprising a plurality of the printhead modules.
798. A printer including a printer controller according to claim 833.

799. A printer including a print engine according to claim 834.

800. A printer controller according to claim 788, for implementing a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier, the nozzles being disposed on the printhead module, the method comprising the steps of:
determining the rotational displacement;
determining at least one correction factor that at least partially compensates for the ink dot displacement; and using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

801. A printer controller according to claim 833 for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

802. A printer controller according to claim 788, for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:
(a) providing a fire signal to nozzles at a first and nth position in each set of nozzles;
providing a fire signal to the next inward pair of nozzles in each set;
in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

803. A printer controller according to claim 788, manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.
804. A printer controller according to claim 788, for supplying data to a printhead module including:
at least one row of print nozzles;
at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

805. A printer controller according to claim 788, installed in a printer comprising:
a printhead comprising at least a first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

806. A printer controller according to claim 788, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

807. A printer controller according to claim 788, installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

808. A printer controller according to claim 788, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

809. A printer controller according to claim 788, for supplying dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:
access a correction factor associated with the at least one printhead module;
determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

810. A printer controller according to claim 788, for supplying dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

811. A printer controller according to claim 788, for controlling a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

812. A printer controller according to claim 788, for outputting to a printhead module:
dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;
the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.

813. A printer controller according to claim 788, for supplying data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

814. A printer controller according to claim 788, for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:
a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;
wherein the printer controller is selectively configurable to supply dot data for the first and second modes.

815. A printer controller according to claim 788, for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

816. A printer controller according to claim 788, for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:
a fire signal is provided to nozzles at a first and nth position in each set of nozzles;
a fire signal is provided to the next inward pair of nozzles in each set;
in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired; and in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

817. A printer controller according to claim 788, for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

818. A printer controller according to claim 788, for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

819. A printer controller according to claim 788, for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

820. A printer controller according to claim 788, for supplying data to a printhead module including:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

821. A printer controller according to claim 788, for supplying data to a printhead capable of printing a maximum of n of channels of print data, the printhead being configurable into:
a first mode, in which the printhead is configured to receive print data for a first number of the channels; and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

822. A printer controller according to claim 788, for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

823. A printer controller according to claim 788, for supplying data to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

824. A printer controller according to claim 788, for supplying data to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:
in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

825. A printer controller according to claim 788, for supplying data to a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

826. A printer controller according to claim 788, for supplying data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

827. A printer controller according to claim 788, for supplying data to a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

828. A printer controller according to claim 788, for supplying data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

829. A printer controller according to claim 788, for providing data to a printhead module that includes:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

830. A printer controller according to claim 788, for supplying data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

831. A printer controller according to claim 788, for supplying data to a printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

832. A printer controller for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

833. A print engine comprising a printer controller according to claim 877 and the at least one printhead module, wherein each nozzle in the first row is paired with a nozzle in the second row, such that each pair of nozzles is aligned in an intended direction of print media travel relative to the printhead module.

834. A print engine according to claim 833, including a plurality of sets of the first and second rows.

835. A print engine according to claim 834, wherein each of the sets of the first and second rows is configured to print in a single color or ink type.

836. A print engine according to claim 832, wherein each of the rows includes an odd and an even sub-row, the odd and even sub-rows being offset with respect to each other in a direction of print media travel relative to the printhead in use.

837. A print engine according to claim 836, wherein the odd and even sub-rows are transversely offset with respect to each other.

838. A printer including at least one printer controller according to claim 877.

839. A printer including at least one print engine according to claim 878.

840. A printer controller according to claim 832, for implementing a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier, the nozzles being disposed on the printhead module, the method comprising the steps of:
determining the rotational displacement;
determining at least one correction factor that at least partially compensates for the ink dot displacement; and using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

841. A printer controller according to claim 877 for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

842. A printer controller according to claim 832, for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:
(a) providing a fire signal to nozzles at a first and nth position in each set of nozzles;
(b) providing a fire signal to the next inward pair of nozzles in each set;
(c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and (d) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

843. A printer controller according to claim 832, manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.

844. A printer controller according to claim 832, for supplying data to a printhead module including:
at least one row of print nozzles;
at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

845. A printer controller according to claim 832, installed in a printer comprising:
a printhead comprising at least a first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

846. A printer controller according to claim 832, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

847. A printer controller according to claim 832, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

848. A printer controller according to claim 832, installed in a printer comprising:

a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

849. A printer controller according to claim 832, for supplying dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:
access a correction factor associated with the at least one printhead module;
determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

850. A printer controller according to claim 832, for supplying dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

851. A printer controller according to claim 832, for controlling a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

852. A printer controller according to claim 832, for outputting to a printhead module:
dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;
the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.

853. A printer controller according to claim 832, for supplying data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

854. A printer controller according to claim 832, for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:
a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;
wherein the printer controller is selectively configurable to supply dot data for the first and second modes.

855. A printer controller according to claim 832, for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

856. A printer controller according to claim 832, for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:
a fire signal is provided to nozzles at a first and nth position in each set of nozzles;
a fire signal is provided to the next inward pair of nozzles in each set;
in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired; and in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

857. A printer controller according to claim 832, for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

858. A printer controller according to claim 832, for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

859. A printer controller according to claim 832, for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

860. A printer controller according to claim 832, for supplying data to a printhead module including:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

861. A printer controller according to claim 832, for supplying data to a printhead capable of printing a maximum of n of channels of print data, the printhead being configurable into:
a first mode, in which the printhead is configured to receive print data for a first number of the channels; and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

862. A printer controller according to claim 832, for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

863. A printer controller according to claim 832, for supplying data to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

864. A printer controller according to claim 832, for supplying data to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:
in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

865. A printer controller according to claim 832, for supplying data to a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

866. A printer controller according to claim 832, for supplying data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

867. A printer controller according to claim 832, for supplying data to a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

868. A printer controller according to claim 832, for supplying data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

869. A printer controller according to claim 832, for providing data to a printhead module that includes:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

870. A printer controller according to claim 832, for supplying data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

871. A printer controller according to claim 832, for supplying data to a printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

872. A printer controller for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead, wherein each of the serial outputs is configured to supply dot data for at least two channels of the at least one printhead.

873. A printer controller according to claim 872, wherein the at least two channels include at least two color channels.

874. A printer controller according to claim 872, wherein the at least two channels include at least one fixative channel.

875. A printer controller according to claim 872, wherein the at least two channels include at least one infrared ink channel.

876. A printer controller according to claim 872, wherein the first data includes one or more instructions associated with production of the dot data from the first data, the print controller including processing means for producing the dot data from the first data on the basis of the one or more instructions.

877. A printer controller according to claim 872, wherein the printhead is a pagewidth printhead.

878. A printer controller according to claim 872, for implementing a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier, the nozzles being disposed on the printhead module, the method comprising the steps of:

determining the rotational displacement;
determining at least one correction factor that at least partially compensates for the ink dot displacement; and using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

879. A printer controller according to claim 917 for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

880. A printer controller according to claim 872, for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:
(a) providing a fire signal to nozzles at a first and nth position in each set of nozzles;
(b) providing a fire signal to the next inward pair of nozzles in each set;
(c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

881. A printer controller according to claim 872, manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.

882. A printer controller according to claim 872, for supplying data to a printhead module including:
at least one row of print nozzles;
at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

883. A printer controller according to claim 872, installed in a printer comprising:
a printhead comprising at least a first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

884. A printer controller according to claim 872, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

885. A printer controller according to claim 872, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

886. A printer controller according to claim 872, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

887. A printer controller according to claim 872, for supplying dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:
access a correction factor associated with the at least one printhead module;

determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

888. A printer controller according to claim 872, for supplying dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

889. A printer controller according to claim 872, for controlling a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

890. A printer controller according to claim 872, for outputting to a printhead module:
dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;
the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.

891. A printer controller according to claim 872, for supplying data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

892. A printer controller according to claim 872, for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:
a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;

wherein the printer controller is selectively configurable to supply dot data for the first and second modes.

893. A printer controller according to claim 872, for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

894. A printer controller according to claim 872, for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:
a fire signal is provided to nozzles at a first and nth position in each set of nozzles;
a fire signal is provided to the next inward pair of nozzles in each set;
in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired; and in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

895. A printer controller according to claim 872, for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

896. A printer controller according to claim 872, for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

897. A printer controller according to claim 872, for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

898. A printer controller according to claim 872, for supplying data to a printhead module including:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

899. A printer controller according to claim 872, for supplying data to a printhead capable of printing a maximum of n of channels of print data, the printhead being configurable into:
a first mode, in which the printhead is configured to receive print data for a first number of the channels; and second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

900. A printer controller according to claim 872, for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

901. A printer controller according to claim 872, for supplying data to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

902. A printer controller according to claim 872, for supplying data to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:
in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

903. A printer controller according to claim 872, for supplying data to a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

904. A printer controller according to claim 872, for supplying data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

905. A printer controller according to claim 872, for supplying data to a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

906. A printer controller according to claim 872, for supplying data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

907. A printer controller according to claim 872, for providing data to a printhead module that includes:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

908. A printer controller according to claim 872, for supplying data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

909. A printer controller according to claim 872, for supplying data to a printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

910. A printhead module including:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

911. A printhead module according to claim 910, wherein there is a one to one correspondence between the nozzles and respective elements of the first and second shift registers.

912. A printhead module according to claim 911, wherein each of the shift registers supplies dot data to about half of the nozzles in a row.

913. A printhead module according to claim 910, including at least one pair of rows of the nozzles, the rows in each pair being offset in a direction parallel to the rows by half the intra-row nozzle spacing.

914. A printhead module according to claim 914, wherein each of the at least two shift registers supplies dot data to at least some of the nozzles in at least the pair of rows.

915. A printhead module according claim 910, including a plurality of the rows configured to print using at least two ink channels, the nozzles for each of the ink channels being fed the dot data from at least one pair of first and second registers.

916. A printhead module according to claim 910, configured to receive dot data to which a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier has been applied, the nozzles being disposed on the printhead module, the method comprising the steps of:
determining the rotational displacement;
determining at least one correction factor that at least partially compensates for the ink dot displacement; and using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

917. A printhead module according to claim 910, configured to receive dot data to which a method of expelling ink has been applied, the method being applied to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

918. A printhead module according to claim 910, configured to receive dot data to which a method of expelling ink has been applied, the method being applied to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:
(a) providing a fire signal to nozzles at a first and nth position in each set of nozzles;
(b) providing a fire signal to the next inward pair of nozzles in each set;
(c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and (d) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

919. A printhead module according to claim 910, having been manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.

920. A printhead module according to claim 910, including:
at least one row of print nozzles;
at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

921. A printhead module according to claim 910, installed in a printer comprising:
a printhead comprising at least the first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

922. A printhead module according to claim 910, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

923. A printhead module according to claim 910, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

924. A printhead module according to claim 910, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

925. A printhead module according to claim 910, in communication with a printer controller for supplying dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:
access a correction factor associated with the at least one printhead module;
determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

926. A printhead module according to claim 910, in communication with a printer controller for supplying dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

927. A printhead module according to claim 910, in communication with a printer controller for controlling a head comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

928. A printhead module according to claim 910, in communication with a printer controller for outputting to a printhead module:
dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;
the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.

929. A printhead module according to claim 910, including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

930. A printhead module according to claim 910, in communication with a printer controller for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:
a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;
wherein the printer controller is selectively configurable to supply dot data for the first and second modes.

931. A printhead module according to claim 910, in communication with a printer controller for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

932. A printhead module according to claim 910, used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:
(a) a fire signal is provided to nozzles at a first and nth position in each set of nozzles;
(b) a fire signal is provided to the next inward pair of nozzles in each set;
(c) in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired;
and (d) in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

933. A printhead module according to claim 910, used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

934. A printhead module according to claim 910, in communication with a printer controller for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

935. A printhead module according to claim 910, in communication with a printer controller for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

936. A printhead module according to claim 910, in communication with a printer controller for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

937. A printhead module according to claim 910, including:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

938. A printhead module according to claim 955 being capable of printing a maximum of n of channels of print data, the printhead being configurable into:
a first mode, in which the printhead is configured to receive print data for a first number of the channels; and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

939. A printhead comprising a plurality of printhead modules according to claim 910, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

940. A printhead module according to claim 910, including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

941. A printhead module according to claim 910, including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:
in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

942. A printhead module according to claim 910, for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

943. A printhead module according to claim 910, including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

944. A printhead module according to claim 910, having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

945. A printhead module according to claim 910, comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

946. A printhead module according to claim 910, in communication with a printer controller for providing data to a printhead module that includes:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

947. A printhead module according to claim 910, having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

948. A printhead module according to claim 910, comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

949. A printhead module capable of printing a maximum of n of channels of print data, the printhead module being configurable into:
a first mode, in which the printhead module is configured to receive print data for a first number of the channels;
and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

950. A printhead module according to claim 949, wherein the first number is n.

951. A printhead module according to claim 949, wherein the first number is less than n.

952. A printhead module according to claim 949, configurable into at least one other mode, in which the printhead is configured to receive print data for a number of print channels other than the first and second numbers.

953. A printhead module according to claim 949, wherein n is 4 and the second number is less than 4.

954. A printhead module according to claim 949, wherein n is 5 and the second number is less than 5.

955. A printhead module according to claim 949, wherein n is 6 and the second number is less than 6.

956. A printhead module according to claim 955, wherein the second number is 3, 4 or 5.

957. A printhead module according to claim 949, wherein the selected mode is selected based on the contents of a memory associated with the printhead.

958. A printhead module according to claim 957, wherein the memory is a register.

959. A printhead module according to claim 957, wherein the register is on an integrated circuit, and wherein the integrated circuit and the printhead are mounted to a print engine.

960. A printhead according to claim 949, comprising a plurality of printhead modules.

961. A printhead according to claim 960, wherein the printhead is a pagewidth printhead.

962. A printhead module according to claim 949, configured to receive dot data to which a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier has been applied, the nozzles being disposed on the printhead module, the method comprising the steps of:
determining the rotational displacement;
determining at least one correction factor that at least partially compensates for the ink dot displacement; and using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

963. A printhead module according to claim 949, configured to receive dot data to which a method of expelling ink has been applied, the method being applied to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

964. A printhead module according to claim 949, configured to receive dot data to which a method of expelling ink has been applied, the method being applied to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:
providing a fire signal to nozzles at a first and nth position in each set of nozzles;
providing a fire signal to the next inward pair of nozzles in each set;
in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

965. A printhead module according to claim 949, having been manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.

966. A printhead module according to claim 949, including:
at least one row of print nozzles;
at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

967. A printhead module according to claim 949, installed in a printer comprising:
a printhead comprising at least the first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

968. A printhead module according to claim 949, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

969. A printhead module according to claim 949, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

970. A printhead module according to claim 949, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

971. A printhead module according to claim 949, in communication with a printer controller for supplying dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:
access a correction factor associated with the at least one printhead module;
determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

972. A printhead module according to claim 949, in communication with a printer controller for supplying dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

973. A printhead module according to claim 949, in communication with a printer controller for controlling a head comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

974. A printhead module according to claim 949, in communication with a printer controller for outputting to a printhead module:
dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;
the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.
975. A printhead module according to claim 949, including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

976. A printhead module according to claim 949, in communication with a printer controller for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:
a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;
wherein the printer controller is selectively configurable to supply dot data for the first and second modes.

977. A printhead module according to claim 949, in communication with a printer controller for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

978. A printhead module according to claim 949, used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:
(a) a fire signal is provided to nozzles at a first and nth position in each set of nozzles;
(b) a fire signal is provided to the next inward pair of nozzles in each set;
(c) in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired;
and (d) in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

979. A printhead module according to claim 949, used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

980. A printhead module according to claim 949, in communication with a printer controller for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

981. A printhead module according to claim 949, in communication with a printer controller for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

982. A printhead module according to claim 949, in communication with a printer controller for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

983. A printhead module according to claim 949, including:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

984. A printhead comprising a plurality of printhead modules according to claim 949, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

985. A printhead module according to claim 949, including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

986. A printhead module according to claim 949, including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:
in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

987. A printhead module according to claim 949, for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

988. A printhead module according to claim 949, including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

989. A printhead module according to claim 949, having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

990. A printhead module according to claim 949, comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

991. A printhead module according to claim 949, in communication with a printer controller for providing data to a printhead module that includes:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

992. A printhead module according to claim 949, having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

993. A printhead module according to claim 949, comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

994. A printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

995. A printhead according to claim 994, comprising a plurality of at least one of the types of module.

996. A printhead according to claim 995, comprising a plurality of each of at least two of the types of module.
997. A printhead according to claim 994, comprising two types of the module.

998. A printhead according to claim 997, wherein the two types of module alternate across a print width of the printhead.

999. A printhead according to claim 994, each of the modules including at least one row of print nozzles, wherein each of the at least one row of print nozzles includes at least a portion that extends at an acute angle to an intended relative direction of movement between the printhead and print media.

1000. A printhead according to claim 999, wherein the different types of modules are configured, and arranged relative to each other, such that there is substantially no growth in offset of each of the at least one row of print nozzles in a direction across an intended print width of the printhead.

1001. A printhead according to claim 994, wherein each of the printhead modules is a monolithic integrated circuit.

1002. A printhead according to claim 994, each of the modules including at least one row of print nozzles, wherein each of the at least one rows includes at least two sub-rows, each of the sub-rows being parallel to each other and displaced relative to each other in a direction of intended movement of print media relative to the printhead.

1003. A printhead according to claim 994, the printhead being a pagewidth printhead.
1004. A printhead according to claim 1000, the printhead being a pagewidth printhead.
1005. A printhead according to claim 1004, the printhead being a pagewidth printhead.

1006. A printhead according to claim 994, configured to receive dot data to which a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier has been applied, the nozzles being disposed on the printhead module, the method comprising the steps of:
determining the rotational displacement;
determining at least one correction factor that at least partially compensates for the ink dot displacement; and using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

1007. A printhead according to claim 994, configured to receive dot data to which a method of expelling ink has been applied, the method being applied to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

1008. A printhead according to claim 994, configured to receive dot data to which a method of expelling ink has been applied, the method being applied to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:
providing a fire signal to nozzles at a first and nth position in each set of nozzles;
providing a fire signal to the next inward pair of nozzles in each set;
in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

1009. A printhead according to claim 994, having been manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.

1010. A printhead according to claim 994, including:
at least one row of print nozzles;
at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

1011. A printhead according to claim 994, installed in a printer comprising:

a printhead comprising at least the first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

1012. A printhead according to claim 994, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

1013. A printhead according to claim 994, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

1014. A printhead according to claim 994, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

1015. A printhead according to claim 994, in communication with a printer controller for supplying dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:

access a correction factor associated with the at least one printhead module;
determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

1016. A printhead according to claim 994, in communication with a printer controller for supplying dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

1017. A printhead according to claim 994, in communication with a printer controller for controlling a head comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

1018. A printhead according to claim 994, in communication with a printer controller for outputting to a printhead module:
dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;
the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.

1019. A printhead according to claim 994, including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

1020. A printhead according to claim 994, in communication with a printer controller for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:
a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;
wherein the printer controller is selectively configurable to supply dot data for the first and second modes.

1021. A printhead according to claim 994, in communication with a printer controller for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

1022. A printhead according to claim 994, used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:
a fire signal is provided to nozzles at a first and nth position in each set of nozzles;
a fire signal is provided to the next inward pair of nozzles in each set;
in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired; and in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

1023. A printhead according to claim 994, used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

1024. A printhead according to claim 994, in communication with a printer controller for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

1025. A printhead according to claim 994, in communication with a printer controller for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

1026. A printhead according to claim 994, in communication with a printer controller for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

1027. A printhead according to claim 994, including:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

1028. A printhead according to claim 1039 being capable of printing a maximum of n of channels of print data, the printhead being configurable into:
a first mode, in which the printhead is configured to receive print data for a first number of the channels; and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

1029. A printhead according to claim 994, including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence:
[nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

1030. A printhead according to claim 994, including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:
in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

1031. A printhead according to claim 994, for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

1032. A printhead according to claim 994, including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

1033. A printhead according to claim 994, having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

1034. A printhead according to claim 994, comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

1035. A printhead according to claim 994, in communication with a printer controller for providing data to a printhead module that includes:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

1036. A printhead according to claim 994, having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

1037. A printhead according to claim 994, comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

1038. A printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

1039. A printhead module according to claim 1038, wherein the nozzle at each given position within the set is fired simultaneously with the nozzles in the other sets at respective corresponding positions.

1040. A printhead module according to claim 1038, wherein the printhead module includes a plurality of the rows of nozzles, the printhead module being configured to fire all the nozzles on each row prior to firing any nozzles from a subsequent row.

1041. A printhead module according to claim 1039, wherein the rows are disposed in pairs.

1042. A printhead module according to claim 1040, wherein the rows in each pair of rows are offset relative to each other.

1043. A printhead module according to claim 1041, wherein each pair of rows is configured to print the same color ink.

1044. A printhead module according to claim 1042, wherein each pair of rows is connected to a common ink source.

1045. A printhead module according to claim 1038, wherein the sets of nozzles are adjacent each other.

1046. A printhead module according to claim 1038, wherein the sets of nozzles are separated by an intermediate nozzle, the intermediate nozzle being fired either prior to the nozzle at position 1 in each set, or following the nozzle at position n.

1047. A printhead comprising a plurality of printhead modules according to claim 1083.

1048. A printhead according to claim 1047, wherein the printhead is a pagewidth printhead.

1049. A printhead module according to claim 1038, configured to receive dot data to which a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier has been applied, the nozzles being disposed on the printhead module, the method comprising the steps of:
determining the rotational displacement;
determining at least one correction factor that at least partially compensates for the ink dot displacement; and using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

1050. A printhead module according to claim 1038, configured to receive dot data to which a method of expelling ink has been applied, the method being applied to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

1051. A printhead module according to claim 1038, configured to receive dot data to which a method of expelling ink has been applied, the method being applied to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:
providing a fire signal to nozzles at a first and nth position in each set of nozzles;
providing a fire signal to the next inward pair of nozzles in each set;
in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

1052. A printhead module according to claim 1038, having been manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.

1053. A printhead module according to claim 1038, including:
at least one row of print nozzles;
at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

1054. A printhead module according to claim 1038, installed in a printer comprising:
a printhead comprising at least the first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

1055. A printhead module according to claim 1038, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

1056. A printhead module according to claim 1038, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

1057. A printhead module according to claim 1038, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

1058. A printhead module according to claim 1038, in communication with a printer controller for supplying dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:
access a correction factor associated with the at least one printhead module;
determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

1059. A printhead module according to claim 1038, in communication with a printer controller for supplying dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

1060. A printhead module according to claim 1038, in communication with a printer controller for controlling a head comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

1061. A printhead module according to claim 1038, in communication with a printer controller for outputting to a printhead module:
dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;
the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.

1062. A printhead module according to claim 1038, including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

1063. A printhead module according to claim 1038, in communication with a printer controller for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:
a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;
wherein the printer controller is selectively configurable to supply dot data for the first and second modes.

1064. A printhead module according to claim 1038, in communication with a printer controller for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

1065. A printhead module according to claim 1038, used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:
(a) a fire signal is provided to nozzles at a first and nth position in each set of nozzles;
(b) a fire signal is provided to the next inward pair of nozzles in each set;
(c) in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired;
and (d) in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

1066. A printhead module according to claim 1038, used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

1067. A printhead module according to claim 1038, in communication with a printer controller for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

1068. A printhead module according to claim 1038, in communication with a printer controller for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

1069. A printhead module according to claim 1038, in communication with a printer controller for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

1070. A printhead module according to claim 1038, including:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

1071. A printhead module according to claim 1083 being capable of printing a maximum of n of channels of print data, the printhead being configurable into:
a first mode, in which the printhead is configured to receive print data for a first number of the channels; and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

1072. A printhead comprising a plurality of printhead modules according to claim 1038, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

1073. A printhead module according to claim 1038, including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:
in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

1074. A printhead module according to claim 1038, for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

1075. A printhead module according to claim 1038, including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

1076. A printhead module according to claim 1038, having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

1077. A printhead module according to claim 1038, comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

1078. A printhead module according to claim 1038, in communication with a printer controller for providing data to a printhead module that includes:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

1079. A printhead module according to claim 1038, having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

1080. A printhead module according to claim 1038, comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

1081. A printhead module according to claim 1038, comprising a plurality of the rows, the printhead module being configured to fire each nozzle in each row simultaneously with the nozzle or nozzles at the same position in the other rows.

1082. A printhead module according to claim 1038, including a plurality of pairs of the rows, each pair of rows including an odd row and an even row, the odd and even rows in each pair being offset from each other in both x and y directions relative to an intended direction of print media movement relative to the printhead, the printhead module being configured to cause firing of at least a plurality of the odd rows prior to firing any of the even rows, or vice versa.

1083. A printhead module according to claim 1082, wherein all the odd rows are fired before any of the even rows are fired, or vice versa.

1084. A printhead module according to claim 1082, wherein all the odd rows, or the even rows, or both, are fired in a predetermined order.

1085. A printhead module according to claim 1084, configurable such that the predetermined order is selectable from a plurality of predetermined available orders.

1086. A printhead module according to claim 1082, wherein the predetermined order is sequential.
1087. A printhead module according to claim 1086, configurable such that the predetermined order can commence at any of a plurality of the rows.

1088. A printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:
in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

1089. A printhead module according to claim 1088, wherein the printhead module includes a plurality of the rows of nozzles, the printhead module being configured to fire all the nozzles on each row prior to firing any nozzles from a subsequent row.

1090. A printhead module according to claim 1089, wherein the rows are disposed in pairs.

1091. A printhead module according to claim 1090, wherein the rows in each pair of rows are offset relative to each other.

1092. A printhead module according to claim 1091, wherein each pair of rows is configured to print the same color ink.

1093. A printhead module according to claim 1092, wherein each pair of rows is connected to a common ink source.

1094. A printhead module according to claim 1088, wherein the sets of nozzles are adjacent each other.
1095. A printhead module according to claim 1088, wherein the sets of nozzles are separated by an intermediate nozzle, the intermediate nozzle being fired either prior to the nozzle at position 1 in each set, or following the nozzle at position n.

1096. A printhead module according to claim 1088, configured to receive dot data to which a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier has been applied, the nozzles being disposed on the printhead module, the method comprising the steps of:
determining the rotational displacement;
determining at least one correction factor that at least partially compensates for the ink dot displacement; and using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

1097. A printhead module according to claim 1088, configured to receive dot data to which a method of expelling ink has been applied, the method being applied to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

1098. A printhead module according to claim 1088, configured to receive dot data to which a method of expelling ink has been applied, the method being applied to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:
(a) providing a fire signal to nozzles at a first and nth position in each set of nozzles;
(b) providing a fire signal to the next inward pair of nozzles in each set;
(c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and (d) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

1099. A printhead module according to claim 1088, having been manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.

1100. A printhead module according to claim 1088, including:
at least one row of print nozzles;
at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

1101. A printhead module according to claim 1088, installed in a printer comprising:
a printhead comprising at least the first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

1102. A printhead module according to claim 1088, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

1103. A printhead module according to claim 1088, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

1104. A printhead module according to claim 1088, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

1105. A printhead module according to claim 1088, in communication with a printer controller for supplying dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:
access a correction factor associated with the at least one printhead module;
determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

1106. A printhead module according to claim 1088, in communication with a printer controller for supplying dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

1107. A printhead module according to claim 1088, in communication with a printer controller for controlling a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

1108. A printhead module according to claim 1088, in communication with a printer controller for outputting to a printhead module:
dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;
the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.
1109. A printhead module according to claim 1088, including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

1110. A printhead module according to claim 1088, in communication with a printer controller for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:
a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;
wherein the printer controller is selectively configurable to supply dot data for the first and second modes.
1111. A printhead module according to claim 1088, in communication with a printer controller for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

1112. A printhead module according to claim 1088, used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:
(a) a fire signal is provided to nozzles at a first and nth position in each set of nozzles;

(b) a fire signal is provided to the next inward pair of nozzles in each set;
(c) in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired;
and (d) in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

1113. A printhead module according to claim 1088, used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

1114. A printhead module according to claim 1088, in communication with a printer controller for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

1115. A printhead module according to claim 1088, in communication with a printer controller for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

1116. A printhead module according to claim 1088, in communication with a printer controller for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.
1117. A printhead module according to claim 1088, including:

at least one row of print nozzles;

at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

1118. A printhead module according to claim 1133 being capable of printing a maximum of n of channels of print data, the printhead being configurable into:
a first mode, in which the printhead is configured to receive print data for a first number of the channels; and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

1119. A printhead comprising a plurality of printhead modules according to claim 1088, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

1120. A printhead module according to claim 1088, including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

1121. A printhead module according to claim 1088, for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

1122. A printhead module according to claim 1088, including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

1123. A printhead module according to claim 1088, having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

1124. A printhead module according to claim 1088, comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

1125. A printhead module according to claim 1088, in communication with a printer controller for providing data to a printhead module that includes:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

1126. A printhead module according to claim 1088, having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

1127. A printhead module according to claim 1088, comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

1128. A printhead module according to claim 1088, comprising a plurality of the rows, the printhead module being configured to fire each nozzle in each row simultaneously with the nozzle or nozzles at the same position in the other rows.

1129. A printhead module according to claim 1088, including a plurality of pairs of the rows, each pair of rows including an odd row and an even row, the odd and even rows in each pair being offset from each other in both x and y directions relative to an intended direction of print media movement relative to the printhead, the printhead module being configured to cause firing of at least a plurality of the odd rows prior to firing any of the even rows, or vice versa.

1130. A printhead module according to claim 1129, wherein all the odd rows are fired before any of the even rows are fired, or vice versa.

1131. A printhead module according to claim 1129, wherein all the odd rows, or the even rows, or both, are fired in a predetermined order.

1132. A printhead module according to claim 1131, configurable such that the predetermined order is selectable from a plurality of predetermined available orders.

1133. A printhead module according to claim 1129, wherein the predetermined order is sequential.

1134. A printhead module according to claim 1133, configurable such that the predetermined order can commence at any of a plurality of the rows.

1135. A printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

1136. A printhead module according to claim 1135, wherein the communication input is configured to receive the dot data and control data serially.

1137. A printhead module according to claim 1135, further including a plurality of the communication inputs.

1138. A printhead module according to claim 1136, further including a plurality of the communication inputs.

1139. A printhead comprising a plurality of printhead modules according to claim 1135, the printhead modules being disposed end to end for printing a width exceeding that of any of the individual printhead modules, the communications input of each of the printhead modules being connected to a common dot data and control data bus.

1140. A printhead according to claim 1139, wherein each module is configured to respond to dot data and control data on the bus only when it is intended for that module.

1141. A printhead module according to claim 1135, configured to receive dot data to which a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier has been applied, the nozzles being disposed on the printhead module, the method comprising the steps of:
determining the rotational displacement;
determining at least one correction factor that at least partially compensates for the ink dot displacement; and using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

1142. A printhead module according to claim 1] 35, configured to receive dot data to which a method of expelling ink has been applied, the method being applied to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

1143. A printhead module according to claim 1135, configured to receive dot data to which a method of expelling ink has been applied, the method being applied to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:
providing a fire signal to nozzles at a first and nth position in each set of nozzles;
providing a fire signal to the next inward pair of nozzles in each set;
in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

1144. A printhead module according to claim 1135, having been manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.

1145. A printhead module according to claim 1135, including:
at least one row of print nozzles;
at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

1146. A printhead module according to claim 1135, installed in a printer comprising:
a printhead comprising at least the first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

1147. A printhead module according to claim 1135, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

1148. A printhead module according to claim 1135, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

1149. A printhead module according to claim 1135, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

1150. A printhead module according to claim 1135, in communication with a printer controller for supplying dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:
access a correction factor associated with the at least one printhead module;
determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

1151. A printhead module according to claim 1135, in communication with a printer controller for supplying dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

1152. A printhead module according to claim 1135, in communication with a printer controller for controlling a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

1153. A printhead module according to claim 1135, in communication with a printer controller for outputting to a printhead module:
dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;
the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.

1154. A printhead module according to claim 1135, including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

1155. A printhead module according to claim 1135, in communication with a printer controller for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:
a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;
wherein the printer controller is selectively configurable to supply dot data for the first and second modes.

1156. A printhead module according to claim 1135, in communication with a printer controller for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

1157. A printhead module according to claim 1135, used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:
(a) a fire signal is provided to nozzles at a first and nth position in each set of nozzles;
(b) a fire signal is provided to the next inward pair of nozzles in each set;
(c) in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired;
and (d) in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

1158. A printhead module according to claim 1135, used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

1159. A printhead module according to claim 1135, in communication with a printer controller for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

1160. A printhead module according to claim 1135, in communication with a printer controller for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

1161. A printhead module according to claim 1135, in communication with a printer controller for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

1162. A printhead module according to claim 1135, including:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

1163. A printhead module according to claim 1180 being capable of printing a maximum of n of channels of print data, the printhead being configurable into:
a first mode, in which the printhead is configured to receive print data for a first number of the channels; and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

1164. A printhead comprising a plurality of printhead modules according to claim 1135, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

1165. A printhead module according to claim 1135, including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

1166. A printhead module according to claim 1135, including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:
in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

1167. A printhead module according to claim 1135, including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

1168. A printhead module according to claim 1135, having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

1169. A printhead module according to claim 1135, comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

1170. A printhead module according to claim 1135, in communication with a printer controller for providing data to a printhead module that includes:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

1171. A printhead module according to claim 1135, having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

1172. A printhead module according to claim 1135, comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

1173. A printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

1174. A printhead module according to claim 1173, wherein the displaced row portion is disposed adjacent one end of the monolithic printhead module.

1175. A printhead module according to claim 1173, including a plurality of the rows, wherein each of at least a plurality of the rows includes one of the displaced row portions.

1176. A printhead module according to claim 1175, wherein the displaced row portions of at least some of the rows are different in length than the displaced row portions of at least some of the other rows.

1177. A printhead module according to claim 1176, wherein each of the rows has a displaced row portion, and the sizes of the respective displaced row portions increase from row to row in the direction normal to that of the pagewidth to be printed.

1178. A printhead module according to claim 1177, wherein the dropped rows together comprise a generally trapezoidal shape, in plan.

1179. A printhead module according to claim 1177, wherein the dropped rows together comprise a generally triangular shape, in plan.

1180. A printhead comprising a plurality of printhead modules, including at least one of the printhead modules according to claim 1218.

1181. A printhead comprising a plurality of printhead modules, including at least one the printhead modules according to claim 2, wherein the displaced row portion of at least one of the printhead modules is disposed adjacent another of the printhead modules.

1182. A printhead according to claim 1181, wherein the printhead modules are the same shape and configuration as each other, and are arranged end to end across the intended print width.

1183. A printhead according to claim 1180, the printhead being a pagewidth printhead.

1184. A printhead according to claim 1182, the printhead being a pagewidth printhead.

1185. A printhead module according to claim 1173, configured to receive dot data to which a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier has been applied, the nozzles being disposed on the printhead module, the method comprising the steps of:
determining the rotational displacement;
determining at least one correction factor that at least partially compensates for the ink dot displacement; and using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

1186. A printhead module according to claim 1173, configured to receive dot data to which a method of expelling ink has been applied, the method being applied to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

1187. A printhead module according to claim 1173, configured to receive dot data to which a method of expelling ink has been applied, the method being applied to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:
providing a fire signal to nozzles at a first and nth position in each set of nozzles;
providing a fire signal to the next inward pair of nozzles in each set;
in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

1188. A printhead module according to claim 1173, having been manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.

1189. A printhead module according to claim 1173, including:
at least one row of print nozzles;
at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

1190. A printhead module according to claim 1173, installed in a printer comprising:
a printhead comprising at least the first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

1191. A printhead module according to claim 1173, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

1192. A printhead module according to claim 1173, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

1193. A printhead module according to claim 1173, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

1194. A printhead module according to claim 1173, in communication with a printer controller for supplying dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:
access a correction factor associated with the at least one printhead module;
determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

1195. A printhead module according to claim 1173, in communication with a printer controller for supplying dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

1196. A printhead module according to claim 1173, in communication with a printer controller for controlling a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

1197. A printhead module according to claim 1173, in communication with a printer controller for outputting to a printhead module:
dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;
the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.

1198. A printhead module according to claim 1173, including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

1199. A printhead module according to claim 1173, in communication with a printer controller for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:
a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;
wherein the printer controller is selectively configurable to supply dot data for the first and second modes.

1200. A printhead module according to claim 1173, in communication with a printer controller for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

1201. A printhead module according to claim 1173, used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:
a fire signal is provided to nozzles at a first and nth position in each set of nozzles;
a fire signal is provided to the next inward pair of nozzles in each set;
in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired; and in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

1202. A printhead module according to claim 1173, used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

1203. A printhead module according to claim 1173, in communication with a printer controller for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

1204. A printhead module according to claim 1173, in communication with a printer controller for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

1205. A printhead module according to claim 1173, in communication with a printer controller for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

1206. A printhead module according to claim 1173, including:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

1207. A printhead module according to claim 1218 being capable of printing a maximum of n of channels of print data, the printhead being configurable into:
a first mode, in which the printhead is configured to receive print data for a first number of the channels; and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

1208. A printhead comprising a plurality of printhead modules according to claim 1173, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

1209. A printhead module according to claim 1173, including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

1210. A printhead module according to claim 1173, including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:
in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

1211. A printhead module according to claim 1173, for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

1212. A printhead module according to claim 1173, having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

1213. A printhead module according to claim 1173, comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

1214. A printhead module according to claim 1173, in communication with a printer controller for providing data to a printhead module that includes:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

1215. A printhead module according to claim 1173, having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

1216. A printhead module according to claim 1173, comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

1217. A printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

1218. A printhead module according to claim 1262 wherein the rows are disposed in pairs extending generally transverse to a direction media is to be moved relative to the printhead.

1219. A printhead module according to claim 1218, wherein the rows in each pair of rows are configured to print the same color ink as each other.

1220. A printhead module according to claim 1219, wherein the rows in each pair of rows share an ink supply.

1221. A printhead module according to claim 1217, wherein the rows in each pair of rows are offset with respect to each other.

1222. A printhead module according to claim 1262 configured to fire the nozzles such that at least some ink dots from one row land on top of dots previously deposited by one or more of the other rows.

1223. A printhead module according to claim 1262 operable in at least two fire modes, wherein at least some of the at least two fire modes define relatively different numbers of nozzles in each of the fire groups.

1224. A printhead module according to claim 1223, wherein at least some of the at least two fire groups define relatively different fire group sequences.

1225. A printhead comprising a plurality of printhead modules according to claim 1262.

1226. A printhead according to claim 1225, wherein the printhead is a pagewidth printhead.

1227. A printhead module according to claim 1262 configured to receive dot data to which a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier has been applied, the nozzles being disposed on the printhead module, the method comprising the steps of:
determining the rotational displacement;
determining at least one correction factor that at least partially compensates for the ink dot displacement; and using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

1228. A printhead module according to claim 1262 configured to receive dot data to which a method of expelling ink has been applied, the method being applied to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

1229. A printhead module according to claim 1262 configured to receive dot data to which a method of expelling ink has been applied, the method being applied to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:
providing a fire signal to nozzles at a first and nth position in each set of nozzles;
providing a fire signal to the next inward pair of nozzles in each set;
in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

1230. A printhead module according to claim 1262 having been manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.

1231. A printhead module according to claim 1262 including:
at least one row of print nozzles;
at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

1232. A printhead module according to claim 1262 installed in a printer comprising:
a printhead comprising at least the first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

1233. A printhead module according to claim 1262 installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

1234. A printhead module according to claim 1262 installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

1235. A printhead module according to claim 1262 installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

1236. A printhead module according to claim 1262 in communication with a printer controller for supplying dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:
access a correction factor associated with the at least one printhead module;
determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

1237. A printhead module according to claim 1262 in communication with a printer controller for supplying dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

1238. A printhead module according to claim 1262 in communication with a printer controller for controlling a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

1239. A printhead module according to claim 1262 in communication with a printer controller for outputting to a printhead module:
dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;
the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.

1240. A printhead module according to claim 1262 including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

1241. A printhead module according to claim 1262 in communication with a printer controller for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:
a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;
wherein the printer controller is selectively configurable to supply dot data for the first and second modes.

1242. A printhead module according to claim 1262 in communication with a printer controller for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

1243. A printhead module according to claim 1262 used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:
(a) a fire signal is provided to nozzles at a first and nth position in each set of nozzles;
(b) a fire signal is provided to the next inward pair of nozzles in each set;
(c) in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired;
and (d) in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

1244. A printhead module according to claim 1262 used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

1245. A printhead module according to claim 1262 in communication with a printer controller for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

1246. A printhead module according to claim 1262 in communication with a printer controller for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

1247. A printhead module according to claim 1262 in communication with a printer controller for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

1248. A printhead module according to claim 1262 including:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

1249. A printhead module according to claim 1 being capable of printing a maximum of n of channels of print data, the printhead being configurable into:
a first mode, in which the printhead is configured to receive print data for a first number of the channels; and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

1250. A printhead comprising a plurality of printhead modules according to claim 1262 the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

1251. A printhead module according to claim 1262 including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

1252. A printhead module according to claim 1262 including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:
in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

1253. A printhead module according to claim 1262 for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

1254. A printhead module according to claim 1262 including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

1255. A printhead module according to claim 1262 comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

1256. A printhead module according to claim 1262 in communication with a printer controller for providing data to a printhead module that includes:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

1257. A printhead module according to claim 1262 having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

1258. A printhead module according to claim 1262 comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

1259. A printhead module according to claim 1262 comprising a plurality of the rows, the printhead module being configured to fire each nozzle in each row simultaneously with the nozzle or nozzles at the same position in the other rows.

1260. A printhead module according to claim 1262 including a plurality of pairs of the rows, each pair of rows including an odd row and an even row, the odd and even rows in each pair being offset from each other in both x and y directions relative to an intended direction of print media movement relative to the printhead, the printhead module being configured to cause firing of at least a plurality of the odd rows prior to firing any of the even rows, or vice versa.

1261. A printhead module according to claim 1260, wherein all the odd rows are fired before any of the even rows are fired, or vice versa.

1262. A printhead module according to claim 1260, wherein all the odd rows, or the even rows, or both, are fired in a predetermined order.

1263. A printhead module according to claim 1262, configurable such that the predetermined order is selectable from a plurality of predetermined available orders.

1264. A printhead module according to claim 1260, wherein the predetermined order is sequential.

1265. A printhead module according to claim 1264, configurable such that the predetermined order can commence at any of a plurality of the rows.

1266. A printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second rows are fired such that some dots output to print media are printed to by nozzles from the first row and at least some other dots output to print media are printed to by nozzles from the second row.

1267. A printhead module according to claim 1266, controllable such that either of the nozzles in each aligned pair of nozzles in the first and second rows can be selected to output ink for a selected dot to be printed on the print media.

1268. A printhead module according to claim 1267, wherein, in the event a nozzle in the first row is faulty, the corresponding nozzle in the second row is selected to output ink for a dot for which the faulty nozzle would otherwise have output ink.

1269. A printhead module according to claim 1267, including a plurality of sets of the first and second rows.

1270. A printhead module according to claim 1269, wherein each of the sets of the first and second rows is configured to print in a single color or ink type.

1271. A printhead module according to claim 1270, wherein the first and second rows in at least one of the sets are separated by one or more rows from the other set or sets.

1272. A printhead module according to claim 1266, wherein each of the rows includes an odd sub-row and an even sub-row, the odd and even sub-rows being offset with respect to each other in a direction of intended print media travel relative to the printhead.

1273. A printhead module according to claim 1272, wherein the odd and even sub-rows are transversely offset relative to each other.

1274. A printhead module according to claim 1266, configured such that the first and second rows are fired alternately.

1275. A printhead comprising a plurality of printhead modules according to claim 1311.

1276. A printhead according to claim 1275, the printhead being a pagewidth printhead.

1277. A printhead module according to claim 1266, configured to receive dot data to which a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier has been applied, the nozzles being disposed on the printhead module, the method comprising the steps of:
determining the rotational displacement;
determining at least one correction factor that at least partially compensates for the ink dot displacement; and using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

1278. A printhead module according to claim 1266, configured to receive dot data to which a method of expelling ink has been applied, the method being applied to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

1279. A printhead module according to claim 1266, configured to receive dot data to which a method of expelling ink has been applied, the method being applied to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:
providing a fire signal to nozzles at a first and nth position in each set of nozzles;
providing a fire signal to the next inward pair of nozzles in each set;
in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

1280. A printhead module according to claim 1266, having been manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.

1281. A printhead module according to claim 1266, including:
at least one row of print nozzles;
at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

1282. A printhead module according to claim 1266, installed in a printer comprising:
a printhead comprising at least the first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

1283. A printhead module according to claim 1266, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

1284. A printhead module according to claim 1266, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

1285. A printhead module according to claim 1266, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

1286. A printhead module according to claim 1266, in communication with a printer controller for supplying dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:
access a correction factor associated with the at least one printhead module;
determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

1287. A printhead module according to claim 1266, in communication with a printer controller for supplying dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

1288. A printhead module according to claim 1266, in communication with a printer controller for controlling a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

1289. A printhead module according to claim 1266, in communication with a printer controller for outputting to a printhead module:
dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;
the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.

1290. A printhead module according to claim 1266, including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

1291. A printhead module according to claim 1266, in communication with a printer controller for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:
a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;
wherein the printer controller is selectively configurable to supply dot data for the first and second modes.

1292. A printhead module according to claim 1266, in communication with a printer controller for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

1293. A printhead module according to claim 1266, used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:
(a) a fire signal is provided to nozzles at a first and nth position in each set of nozzles;
(b) a fire signal is provided to the next inward pair of nozzles in each set;
(c) in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired;
and (d) in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

1294. A printhead module according to claim 1266, used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

1295. A printhead module according to claim 1266, in communication with a printer controller for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

1296. A printhead module according to claim 1266, in communication with a printer controller for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

1297. A printhead module according to claim 1266, in communication with a printer controller for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

1298. A printhead module according to claim 1266, including:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

1299. A printhead module according to claim 1 being capable of printing a maximum of n of channels of print data, the printhead being configurable into:
a first mode, in which the printhead is configured to receive print data for a first number of the channels; and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

1300. A printhead comprising a plurality of printhead modules according to claim 1266, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

1301. A printhead module according to claim 1266, including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

1302. A printhead module according to claim 1266, including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:
in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

1303. A printhead module according to claim 1266, for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

1304. A printhead module according to claim 1266, including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

1305. A printhead module according to claim 1266, having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

1306. A printhead module according to claim 1266, in communication with a printer controller for providing data to a printhead module that includes:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

1307. A printhead module according to claim 1266, having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

1308. A printhead module according to claim 1266, comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

1309. A printer controller for providing data to a printhead module that includes:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

1310. A printer controller according to claim 1309, wherein there is a one to one correspondence between the nozzles and respective elements of the first and second shift registers.

1311. A printer controller according to claim 13 10, wherein each of the shift registers supplies dot data to about half of the nozzles in a row.

1312. A printer controller according to claim 1309, including at least one pair of rows of the nozzles, the rows in each pair being offset in a direction parallel to the rows by half the intra-row nozzle spacing.

1313. A printer controller according to claim 1312, wherein each of the at least two shift registers supplies dot data to at least some of the nozzles in at least the pair of rows.

1314. A printer controller according claim 1309, including a plurality of the rows configured to print using at least two ink channels, the nozzles for each of the ink channels being fed the dot data from at least one pair of first and second registers.

1315. A printer controller according to claim 1314, wherein the printhead module forms part of a printhead.

1316. A printer controller according to claim 1314, wherein the printhead includes a plurality of the printhead modules and the printer controller is configured to supply data to a plurality of the modules.

1317. A printer controller according to claim 1315, wherein the printhead is a pagewidth printhead comprising a plurality of the printhead modules.

1318. A printer controller according to claim 1309, for implementing a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier, the nozzles being disposed on the printhead module, the method comprising the steps of:
determining the rotational displacement;

determining at least one correction factor that at least partially compensates for the ink dot displacement; and using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

1319. A printer controller according to claim 1354 for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

1320. A printer controller according to claim 1309, for implementing a method of expelling ink from a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:
providing a fire signal to nozzles at a first and nth position in each set of nozzles;
providing a fire signal to the next inward pair of nozzles in each set;
in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

1321. A printer controller according to claim 1309, manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.

1322. A printer controller according to claim 1309, for supplying data to a printhead module including:
at least one row of print nozzles;
at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

1323. A printer controller according to claim 1309, installed in a printer comprising:
a printhead comprising at least a first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

1324. A printer controller according to claim 1309, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

1325. A printer controller according to claim 1309, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

1326. A printer controller according to claim 1309, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

1327. A printer controller according to claim 1309, for supplying dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:
access a correction factor associated with the at least one printhead module;
determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

1328. A printer controller according to claim 1309, for supplying dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

1329. A printer controller according to claim 1309, for controlling a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

1330. A printer controller according to claim 1309, for outputting to a printhead module:
dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;
the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.

1331. A printer controller according to claim 1309, for supplying data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

1332. A printer controller according to claim 1309, for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:
a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;
wherein the printer controller is selectively configurable to supply dot data for the first and second modes.

1333. A printer controller according to claim 1309, for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

1334. A printer controller according to claim 1309, for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:
(a) a fire signal is provided to nozzles at a first and nth position in each set of nozzles;
(b) a fire signal is provided to the next inward pair of nozzles in each set;
(c) in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired;
and (d) in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

1335. A printer controller according to claim 1309, for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

1336. A printer controller according to claim 1309, for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

1337. A printer controller according to claim 1309, for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

1338. A printer controller according to claim 1309, for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

1339. A printer controller according to claim 1309, for supplying data to a printhead module including:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

1340. A printer controller according to claim 1309, for supplying data to a printhead capable of printing a maximum of n of channels of print data, the printhead being configurable into:
a first mode, in which the printhead is configured to receive print data for a first number of the channels; and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

1341. A printer controller according to claim 1309, for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

1342. A printer controller according to claim 1309, for supplying data to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

1343. A printer controller according to claim 1309, for supplying data to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:
in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

1344. A printer controller according to claim 1309, for supplying data to a printhead module for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

1345. A printer controller according to claim 1309, for supplying data to a printhead module including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

1346. A printer controller according to claim 1309, for supplying data to a printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

1347. A printer controller according to claim 1309, for supplying data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

1348. A printer controller according to claim 1309, for supplying data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

1349. A printer controller according to claim 1309, for supplying data to a printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

1350. A printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

1351. A printhead module according to claim 1350, configured to modify the operation of the nozzles at or adjacent the at least one thermal sensor, such that operation of nozzles not at or adjacent the at least one thermal sensor is not modified.

1352. A printhead module according to claim 1351, wherein each thermal sensor is associated with a predetermined group of the nozzles, the nozzles in the predetermined group being those for which the operation is modified.

1353. A printhead module according to claim 1352, wherein each thermal sensor is associated with a single nozzle.

1354. A printhead module according to claim 1353, wherein the modification includes preventing operation of the nozzle.

1355. A printhead module according to claim 1354, wherein the modification includes preventing operation of the nozzle for a predetermined period.

1356. A printhead module according to claim 1354, wherein the modification includes preventing operation of the nozzle until the temperature drops below a second threshold.

1357. A printhead module according to claim 1356, wherein the second threshold is lower than the first threshold.

1358. A printhead module according to claim 1357, wherein the second threshold is the same as the first threshold.

1359. A printhead module according to claim 1350, wherein the temperature is not determined explicitly by the at least one thermal sensor or the module.

1360. A printhead module according to claim 1350, wherein the printhead module is a thermal inkjet printhead module and each of the nozzles includes a thermal ink ejection mechanism.

1361. A printhead module according to claim 1360, wherein the thermal sensor comprises at least part of one of the thermal inkjet mechanisms.

1362. A printhead module according to claim 1361, wherein the thermal sensor comprises a heating element.
1363. A printhead module according to claim 1362, wherein the thermal sensor determines the temperature by determining a resistance of the heating element.

1364. A printhead module according to claim 1350, configured to:
output thermal information from the at least one thermal sensor to a controller; and receive control information back from the controller, the control information being indicative of the modification to make to the operation of the one or more nozzles.

1365. A printhead module according to claim 1350, further including a plurality of data latches, the data latches being configured to provide dot data to respective ones of the nozzles, at least some of the data latches being configured to receive thermal signals from respective ones of the thermal sensors during an acquisition period.
1366. A printhead module according to claim 1361, wherein the data latches are configured to form a shift register, the shift register being configured to:
shift the print data in during a print load phase;
sample the signals from the thermal sensors during a temperature load phase;
and shift the thermal signals out during an output phase.

1367. A printhead module according to claim 1366, wherein the output phase coincides with a subsequent print load phase.

1368. A printhead module according to claim 1363, further including logic circuitry configured to perform a bitwise operation on: each thermal signal as it is clocked out of the shift register; and each piece of dot data to be clocked into the shift register, such that when a thermal signal is indicative of a thermal problem with a nozzle, the logic circuitry prevents loading of data that would cause firing of that nozzle.

1369. A printhead module according to claim 1368, wherein the logic circuitry includes an AND circuit that receives as inputs the dot data and the thermal signal corresponding to the nozzle for which the dot data is intended, an output of the AND circuit being in communication with an input of the shift register.

1370. A printhead module according to claim 1350, configured to receive dot data to which a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier has been applied, the nozzles being disposed on the printhead module, the method comprising the steps of:
determining the rotational displacement;
determining at least one correction factor that at least partially compensates for the ink dot displacement; and using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

1371. A printhead module according to claim 1350, configured to receive dot data to which a method of expelling ink has been applied, the method being applied to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

1372. A printhead module according to claim 1350, configured to receive dot data to which a method of expelling ink has been applied, the method being applied to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:
providing a fire signal to nozzles at a first and nth position in each set of nozzles;
providing a fire signal to the next inward pair of nozzles in each set;
in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

1373. A printhead module according to claim 1350, having been manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.

1374. A printhead module according to claim 1350, including:
at least one row of print nozzles;
at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

1375. A printhead module according to claim 1350, installed in a printer comprising:

a printhead comprising at least the first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

1376. A printhead module according to claim 1350, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

1377. A printhead module according to claim 1350, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

1378. A printhead module according to claim 1350, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

1379. A printhead module according to claim 1350, in communication with a printer controller for supplying dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:

access a correction factor associated with the at least one printhead module;
determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

1380. A printhead module according to claim 1350, in communication with a printer controller for supplying dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

1381. A printhead module according to claim 1350, in communication with a printer controller for controlling a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

1382. A printhead module according to claim 1350, in communication with a printer controller for outputting to a printhead module:
dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;
the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.
1383. A printhead module according to claim 1350, including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

1384. A printhead module according to claim 1350, in communication with a printer controller for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:
a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;
wherein the printer controller is selectively configurable to supply dot data for the first and second modes.
1385. A printhead module according to claim 1350, in communication with a printer controller for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

1386. A printhead module according to claim 1350, used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:
(a) a fire signal is provided to nozzles at a first and nth position in each set of nozzles;
(b) a fire signal is provided to the next inward pair of nozzles in each set;
(c) in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired;
and (d) in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

1387. A printhead module according to claim 1350, used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

1388. A printhead module according to claim 1350, in communication with a printer controller for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

1389. A printhead module according to claim 1350, in communication with a printer controller for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

1435, A printhead module according to claim 1350, in communication with a printer controller for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

1391. A printhead module according to claim 1350, including:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

1392. A printhead module according to claim 1395 being capable of printing a maximum of n of channels of print data, the printhead being configurable into:
a first mode, in which the printhead is configured to receive print data for a first number of the channels; and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

1393. A printhead comprising a plurality of printhead modules according to claim 1350, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

1394. A printhead module according to claim 1350, including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.
1395. A printhead module according to claim 1350, including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:
in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

1396. A printhead module according to claim 1350, for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

1397. A printhead module according to claim 1350, including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

1398. A printhead module according to claim 1350, having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

1399. A printhead module according to claim 1350, comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

1400. A printhead module according to claim 1350, in communication with a printer controller for providing data to a printhead module that includes:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

1401. A printhead module according to claim 1350, comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

1402. A printhead module according to claim 1369, further including a logic circuit accepting as inputs a masking signal and the thermal signal corresponding to the nozzle for which the dot data is intended, the logic circuit outputting the thermal signal to the input of the AND circuit in reliance on a value of the masking signal.
1403. A printhead module according to claim 1402, wherein the value of the masking signal enables masking of the thermal signal for at least one nozzle position, including the nozzle for which the current dot data is intended.

1404. A printhead module according to claim 1402, wherein the value of the masking signal enables masking of the thermal signal for a plurality of nozzle positions corresponding to a region of the printhead associated the nozzle for which the current dot data is intended.

1405. A printhead module according to claim 1402, wherein the value of the masking signal enables masking of the thermal signal for all of the nozzle positions of the printhead.

1406. A printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, and being configured such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

1407. A printhead module according to claim 1406, wherein each nozzle in the first row is paired with a nozzle in the second row, such that each pair of nozzles is aligned in an intended direction of print media travel relative to the printhead module.

1408. A printhead module according to claim 1407, including a plurality of sets of the first and second rows.
1409. A printhead module according to claim 1408, wherein each of the sets of the first and second rows is configured to print in a single color or ink type.

1455. A printhead module according to claim 1406, wherein each of the rows includes an odd and an even sub-row, the odd and even sub-rows being offset with respect to each other in a direction of print media travel relative to the printhead in use.

1411. A printhead module according to claim 1410, wherein the odd and even sub-rows are transversely offset with respect to each other.

1412. A printhead comprising a plurality of printhead modules according to claim 1452.

1413. A printhead comprising a plurality of printhead modules according to claim 1454.

1414. A printhead according to claim 1412, the printhead being a pagewidth printhead.

1415. A printhead module according to claim 1406, configured to receive dot data to which a method of at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles due to erroneous rotational displacement of a printhead module relative to a carrier has been applied, the nozzles being disposed on the printhead module, the method comprising the steps of:
determining the rotational displacement;
determining at least one correction factor that at least partially compensates for the ink dot displacement; and using the correction factor to alter the output of the ink dots to at least partially compensate for the rotational displacement.

1416. A printhead module according to claim 1406, configured to receive dot data to which a method of expelling ink has been applied, the method being applied to a printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

1417. A printhead module according to claim 1406, configured to receive dot data to which a method of expelling ink has been applied, the method being applied to a printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising the steps of:
(a) providing a fire signal to nozzles at a first and nth position in each set of nozzles;
(b) providing a fire signal to the next inward pair of nozzles in each set;
(c) in the event n is an even number, repeating step (b) until all of the nozzles in each set has been fired; and (d) in the event n is an odd number, repeating step (b) until all of the nozzles but a central nozzle in each set have been fired, and then firing the central nozzle.

1418. A printhead module according to claim 1406, having been manufactured in accordance with a method of manufacturing a plurality of printhead modules, at least some of which are capable of being combined in pairs to form bilithic pagewidth printheads, the method comprising the step of laying out each of the plurality of printhead modules on a wafer substrate, wherein at least one of the printhead modules is right-handed and at least another is left-handed.

1419. A printhead module according to claim 1406, including:
at least one row of print nozzles;
at least two shift registers for shifting in dot data supplied from a data source to each of the at least one rows, wherein each print nozzle obtains dot data to be fired from an element of one of the shift registers.

1420. A printhead module according to claim 1406, installed in a printer comprising:
a printhead comprising at least the first elongate printhead module, the at least one printhead module including at least one row of print nozzles for expelling ink; and at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first and second printer controllers are connected to a common input of the printhead.

1421. A printhead module according to claim 1406, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein the first printer controller outputs dot data only to the first printhead module and the second printer controller outputs dot data only to the second printhead module, wherein the printhead modules are configured such that no dot data passes between them.

1422. A printhead module according to claim 1406, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data to the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second printhead module; and the second printer controller outputs dot data only to the second printhead module.

1423. A printhead module according to claim 1406, installed in a printer comprising:
a printhead comprising first and second elongate printhead modules, the printhead modules being parallel to each other and being disposed end to end on either side of a join region, wherein the first printhead module is longer than the second printhead module;
at least first and second printer controllers configured to receive print data and process the print data to output dot data for the printhead, wherein: the first printer controller outputs dot data to both the first printhead module and the second controller; and the second printer controller outputs dot data to the second printhead module, wherein the dot data output by the second printer controller includes dot data it generates and at least some of the dot data received from the first printer controller.

1424. A printhead module according to claim 1406, in communication with a printer controller for supplying dot data to at least one printhead module and at least partially compensating for errors in ink dot placement by at least one of a plurality of nozzles on the printhead module due to erroneous rotational displacement of the printhead module relative to a carrier, the printer being configured to:
access a correction factor associated with the at least one printhead module;
determine an order in which at least some of the dot data is supplied to at least one of the at least one printhead modules, the order being determined at least partly on the basis of the correction factor, thereby to at least partially compensate for the rotational displacement; and supply the dot data to the printhead module.

1425. A printhead module according to claim 1406, in communication with a printer controller for supplying dot data to a printhead module having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printer controller being configured to modify operation of at least some of the nozzles in response to the temperature rising above a first threshold.

1426. A printhead module according to claim 1406, in communication with a printer controller for controlling a printhead comprising at least one monolithic printhead module, the at least one printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth of the printhead, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row, wherein the printer controller is configured to provide one or more control signals that control the order of firing of the nozzles.

1427. A printhead module according to claim 1406, in communication with a printer controller for outputting to a printhead module:
dot data to be printed with at least two different inks; and control data for controlling printing of the dot data;
the printer controller including at least one communication output, each or the communication output being configured to output at least some of the control data and at least some of the dot data for the at least two inks.

1428. A printhead module according to claim 1406, including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

1429. A printhead module according to claim 1406, in communication with a printer controller for supplying print data to at least one printhead module capable of printing a maximum of n of channels of print data, the at least one printhead module being configurable into:
a first mode, in which the printhead module is configured to receive data for a first number of the channels; and a second mode, in which the printhead module is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number;
wherein the printer controller is selectively configurable to supply dot data for the first and second modes.

1430. A printhead module according to claim 1406, in communication with a printer controller for supplying data to a printhead comprising a plurality of printhead modules, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

1431. A printhead module according to claim 1406, used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that:
(a) a fire signal is provided to nozzles at a first and nth position in each set of nozzles;
(b) a fire signal is provided to the next inward pair of nozzles in each set;
(c) in the event n is an even number, step (b) is repeated until all of the nozzles in each set has been fired;
and (d) in the event n is an odd number, step (b) is repeated until all of the nozzles but a central nozzle in each set have been fired, and then the central nozzle is fired.

1432. A printhead module according to claim 1406, used in conjunction with a printer controller for supplying one or more control signals to a printhead module, the printhead module including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, the method comprising providing, for each set of nozzles, a fire signal in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

1433. A printhead module according to claim 1406, in communication with a printer controller for supplying dot data to a printhead module comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows, the printer controller being configurable to supply dot data to the printhead module for printing.

1434. A printhead module according to claim 1406, in communication with a printer controller for supplying dot data to at least one printhead module, the at least one printhead module comprising a plurality of rows, each of the rows comprising a plurality of nozzles for ejecting ink, wherein the printhead module includes at least first and second rows configured to print ink of a similar type or color, the printer controller being configured to supply the dot data to the at least one printhead module such that, in the event a nozzle in the first row is faulty, a corresponding nozzle in the second row prints an ink dot at a position on print media at or adjacent a position where the faulty nozzle would otherwise have printed it.

1435. A printhead module according to claim 1406, in communication with a printer controller for receiving first data and manipulating the first data to produce dot data to be printed, the print controller including at least two serial outputs for supplying the dot data to at least one printhead.

1436. A printhead module according to claim 1406, including:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

1437. A printhead module according to claim 1451 being capable of printing a maximum of n of channels of print data, the printhead being configurable into:
a first mode, in which the printhead is configured to receive print data for a first number of the channels; and a second mode, in which the printhead is configured to receive print data for a second number of the channels, wherein the first number is greater than the second number.

1438. A printhead comprising a plurality of printhead modules according to claim 1406, the printhead being wider than a reticle step used in forming the modules, the printhead comprising at least two types of the modules, wherein each type is determined by its geometric shape in plan.

1439. A printhead module according to claim 1406, including at least one row that comprises a plurality of sets of n adjacent nozzles, each of the nozzles being configured to expel ink in response to a fire signal, such that, for each set of nozzles, a fire signal is provided in accordance with the sequence: [nozzle position 1, nozzle position n, nozzle position 2, nozzle position (n-1), ... , nozzle position x], wherein nozzle position x is at or adjacent the centre of the set of nozzles.

1440. A printhead module according to claim 1406, including at least one row that comprises a plurality of adjacent sets of n adjacent nozzles, each of the nozzles being configured to expel the ink in response to a fire signal, the printhead being configured to output ink from nozzles at a first and nth position in each set of nozzles, and then each next inward pair of nozzles in each set, until:
in the event n is an even number, all of the nozzles in each set has been fired; and in the event n is an odd number, all of the nozzles but a central nozzle in each set have been fired, and then to fire the central nozzle.

1441. A printhead module according to claim 1406, for receiving dot data to be printed using at least two different inks and control data for controlling printing of the dot data, the printhead module including a communication input for receiving the dot data for the at least two colors and the control data.

1442. A printhead module according to claim 1406, including at least one row of printhead nozzles, at least one row including at least one displaced row portion, the displacement of the row portion including a component in a direction normal to that of a pagewidth to be printed.

1443. A printhead module according to claim 1406, having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, the nozzles in each row being grouped into at least first and second fire groups, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein the nozzles are fired row by row such that the nozzles of each row are all fired before the nozzles of each subsequent row.

1444. A printhead module according to claim 1406, comprising at least first and second rows configured to print ink of a similar type or color, at least some nozzles in the first row being aligned with respective corresponding nozzles in the second row in a direction of intended media travel relative to the printhead, the printhead module being configurable such that the nozzles in the first and second pairs of rows are fired such that some dots output to print media are printed to by nozzles from the first pair of rows and at least some other dots output to print media are printed to by nozzles from the second pair of rows.

1445. A printhead module according to claim 1406, in communication with a printer controller for providing data to a printhead module that includes:
at least one row of print nozzles;
at least first and second shift registers for shifting in dot data supplied from a data source, wherein each shift register feeds dot data to a group of nozzles, and wherein each of the groups of the nozzles is interleaved with at least one of the other groups of the nozzles.

1446. A printhead module according to claim 1406, having a plurality of nozzles for expelling ink, the printhead module including a plurality of thermal sensors, each of the thermal sensors being configured to respond to a temperature at or adjacent at least one of the nozzles, the printhead module being configured to modify operation of the nozzles in response to the temperature rising above a first threshold.

1447. A first entity configured to authenticate a digital signature supplied by a second entity, wherein one of the entities includes a base key and the other of the entities includes a variant key and a bit-pattern, the variant key being based on the result of applying a one way function to the base key and the bit-pattern, the digital signature having been generated by the second entity using its key to digitally signing at least part of data to be authenticated, the first entity being configured to:
(a) receive the digital signature from the second entity;
(b) receive the data; and (c) authenticate the digital signature based on the received data and the first entity's key.

1448. A first entity according to claim 1447,including the base key, the first entity being configured to receive, from the second entity, the bit-pattern, wherein (c) includes:
generating the variant key from the bit-pattern and the base key; and authenticating the digital signature using the generated variant key.

1449. A first entity according to claim 1448,the first entity storing information, wherein the data is indicative of a request to be performed on the information.

1450. A first entity according to claim 1449,wherein the information is a value.

1451. A first entity according to claim 1448,wherein the data is indicative of a read instruction.

1452. A first entity according to claim 1448,wherein the data is indicate of a write instruction, the data being indicative of new information to be written.

1453. A first entity according to claim 1448,wherein the data is indicative of a function to be applied to the information.

1454. A first entity according to claim 1453,wherein the function is a decrement or increment function.

1455. A first entity according to claim 1448,wherein the data is indicative of a value stored in the second entity.

1456. A first entity according to claim 1448,the first entity being configured to send a request to the second entity, the data being returned in response to the request.

1457. A first entity according to claim 1456,wherein the data is indicative of a value stored in the second entity.

1458. A first entity according to claim 1456,the first entity being configured to digitally sign at least some of the request with the base key.

1459. A first entity according to claim 1447,wherein the first entity has the base key.

1460. A first entity according to claim 1458,the first entity storing information, wherein the data is indicative of a request to be performed on the information.

1461. A first entity according to claim 1459,wherein the information is a value.

1462. A first entity according to claim 1458,wherein the data is indicative of a read instruction.

1463. A first entity according to claim 1458,wherein the data is indicate of a write instruction, the data being indicative of new information to be written.

1464. A first entity according to claim 1458,wherein the data is indicative of a function to be applied to the information.

1465. A first entity according to claim 1463,wherein the function is a decrement or increment function.

1466. A first entity according to claim 1458,wherein the data is indicative of a value stored in the second entity.

1467. A first entity according to claim 1465,the first entity being configured to send a read request to the second entity, the data being returned in response to the request.

1468. A first entity according to claim 1466,wherein the data is indicative of a value stored in the second entity.

1469. A first entity according to claim 1466,the first entity being configured to digitally sign at least some of the request with the base key.

1470. A first entity according to claim 1447,including:
a first bit-pattern a non-volatile memory storing resource data, a first base key for use with at least a first variant key;
a second variant key for use with a second base key, the second variant key being the result of a one way function applied to: the second base key; and the first bit-pattern or a modified bit-pattern based on the first bit-pattern.

1471. A first entity according to claim 1447,configured for use in a method of enabling or disabling a verification process of a first entity in response to a predetermined event, the first entity having at least one associated bit-pattern and at least one variant key, each of the variant keys having been generated by applying a one way function to: a base key; and one or more of the at least one bit-patterns, respectively; or one or more alternative bit patterns, each of the alternative bit-patterns being based on one or the at least one bit-patterns, the method including the method including:
(a) determining that the predetermined event has happened; and (b) enabling or disabling at least one of the first variant keys in response the predetermined event.

1472. A first entity according to claim 1447,for use in a system for enabling authenticated communication between a first entity and at least one other entity, the system including a second entity, wherein:
the first entity and the second entity share transport keys; and the second entity includes at least one authentication key configured to be transported from the second entity to the first entity using the transport keys, the authentication key being usable to enable the authenticated communication by the first entity.

1473. A first entity according to claim 1447,configured for use in a method of storing a first bit-pattern in non-volatile memory of a device, the method comprising:

(a) applying a one way function to a second bit-pattern associated with the device, thereby to generate a first result;
(b) applying a second function to the first result and the first bit-pattern, thereby to generate a second result;
and (c) storing the second result in the memory, thereby indirectly storing the first bit-pattern.

1474. A first entity according to claim 1447,configured for use in a method of storing a bit-pattern in each of a plurality of devices, each of the devices having a memory, the method comprising, for each device:
determining a first memory location; and storing the bit-pattern at the first memory location; wherein the first memory locations are different in at least a plurality of the respective devices.

1475. A first entity according to claim 1447,configured for use in a method of storing at least one functionally identical code segment in each of a plurality of devices, each of the devices having a memory, the method comprising, for each device:
determining a first memory location; and storing a first of the at least one code segments in the memory at the first memory location; wherein the first memory location is different in at least a plurality of the respective devices.

1476. A first entity according to claim 1447,configured for implementing a method for providing a sequence of nonces (R0, R1, R2, ... ) commencing with a current seed of a sequence of seeds (x1, x2, x3,...), the method comprising:
(a) applying a one-way function to the current seed, thereby to generate a current nonce; (b) outputting the current nonce;
(b) using the current seed to generate a next seed in a sequence of seeds, the seed so generated becoming the current seed; and (c) repeating steps (a) to (c) as required to generate further nonces in the sequence of nonces.

1477. A first entity according to claim 1447,configured for implementing a method of storing multiple first bit-patterns in non-volatile memory of a device, the method comprising, for each of the first bit-patterns to be stored:
(a) applying a one way function to a third bit-pattern based on a second bit-pattern associated with the device, thereby to generate a first result;
(b) applying a second function to the first result and the first bit-pattern, thereby to generate a second result;
and (c) storing the second result in the memory, thereby indirectly storing the first bit-pattern;wherein the third bit-patterns used for the respective first bit-patterns are relatively unique compared to each other.

1478. A first entity including:
a first bit-pattern a non-volatile memory storing resource data, a first base key for use with at least a first variant key;
a second variant key for use with a second base key, the second variant key being the result of a one way function applied to: the second base key; and the first bit-pattern or a modified bit-pattern based on the first bit-pattern.

1479. A first entity according to claim 1478,wherein the first variant key is stored in a second entity.

1480. A first entity according to claim 1478,wherein the second base key is stored in a third entity.

1481. A first entity according to claim 1478,configured to receive a request from any of a plurality of second entities, the request being indicative of at least one operation to be performed on the resource data, each of the second entities having an associated bit-pattern and one of the first variant keys, the first variant key in each of second entities being based on the result of applying a one way function to the first base key and the associated bit-pattern of that second entity, the first entity being configured to:
(a) receive the request from one of the second entities;
(b) perform the at least one operation in the request, thereby to generate a response;
(c) use the first base key to digitally sign at least part of the response, thereby to generate a digital signature;
and (d) send the response and the digital signature to the second entity from which the request was received, such that the second entity can verify the at least part of the response using its variant key.

1482. A first entity according to claim 1481,configured to, prior to (b), receive the associated bit-pattern from the second entity that makes the request in (a), wherein (c) includes:
(i) using the first base key and the associated bit-pattern received from the second entity to generate the first variant key of the second entity making the request in (a); and (ii) using the first variant key generated in (i) to perform the signing of at least part of the response the response.

1483. A first entity according to claim 1478,configured to receive a request from any of one or more third entities, the request being indicative of at least one operation to be performed on the resource data, each of the one or more third entities having the second base key, the first entity being configured to:
(a) receive the request from the one of the third entities;
(b) perform the at least one operation in the request, thereby to generate a response;
(c) use the second variant key to digitally sign at least part of the response, thereby to generate a digital signature; and (d) send the response and the digital signature to the third entity from which the request was received, such that the third entity can verify the at least part of the response using its base key.

1484. A first entity according to claim 1483,configured to send the first bit-pattern to the third entity that makes the request in (e), such that the third entity can:
(i) use the second base key and the bit-pattern received from the first entity to generate the second variant key; and (ii) use the second variant key generated in (i) to perform the verification.

1485. A first entity according to claim 1481,configured to receive a request from any of one or more third entities, the request being indicative of at least one operation to be performed on the resource data, each of the one or more third entities having the second base key, the first entity being configured to:
(a) receive the request from the one of the third entities;
(b) perform the at least one operation in the request, thereby to generate a response;
(c) use the first variant key to digitally sign at least part of at least the response, thereby to generate a digital signature; and (d) send the response and the digital signature to the third entity from which the request was received, such that the third entity can verify at least part of the response using its base key.

1486. A first entity according to claim 1485,configured to send the first bit-pattern the third entity that makes the request in (a), such that the third entity can:
(i) use the second base key and the bit-pattern received from the first entity to generate the second variant key; and (ii) use the second variant key generated in (i) to perform the verification.

1487. A first entity according to claim 1485,wherein the second and third entities have different permissions in relation to the operations they can perform on the resource data, the permissions being defined based which of the first and second base key and variant key combinations is used for the verification.

1488. A first entity according to claim 1487,wherein the first base and variant key combination provides a higher permission to perform an operation on the resource data than the second base key and variant key combination.

1489. A first entity according to claim 1486,wherein the second and third entities have different permissions in relation to the operations they can perform on the resource data, the permissions being defined based which of the first and second base key and variant key combinations is used for the verification.

1490. A first entity according to claim 1489, wherein the first base and variant key combination provides a higher permission to perform an operation on the resource data than the second base key and variant key combination.

1491. A first entity according to claim 1478, configured to receive a request from any of a plurality of second entities, the request being indicative of at least one operation to be performed on the resource data, each of the second entities having an associated bit-pattern and one of the first variant keys, the first variant key in each of second entities being based on the result of applying a one way function to the first base key and the associated bit-pattern of that second entity, the first entity being configured to:
(a) receive the request from one of the second entities;
(b) receive the bit-pattern associated with the entity from which the request was received;
(c) receive a digital signature from the entity from which the request was received, the digital signature having been generated by digitally signing at least part of the request using the variant key;
(d) generate the variant key of the entity from which the request sent, by applying the one way function to the first base key and the received bit pattern; and (e) verify the request by digitally signing at least part of the request using the variant key generated in (d) and comparing the produced signature against the signature received in (d).

1492. A first entity according to claim 1478,configured to receive a request from any of one or more third entities, the request being indicative of at least one operation to be performed on the resource data, each of the one or more third entities having the second base key, the first entity being configured to:
(a) receive the request from the one of the third entities;
(b) receive a digital signature from the third entity from which the request was received, the digital signature having been generated by the third entity signing at least part of the request using the second variant key;
(c) verify the at least part of the request by digitally signing at least part of the request using the second variant key and comparing the produced signature against the signature received in (g).

1493. A first entity according to claim 1492, configured to send the first bit-pattern to the third entity that makes the request in (f), such that the third entity can:
use the second base key and the bit-pattern received from the first entity to generate the second variant key; and use the second variant key generated in (i) to digitally sign at least part of the request; and send the request for receipt by the first entity in (a).

1494. A first entity according to claim 1491, configured to receive a request from any of one or more third entities, the request being indicative of at least one operation to be performed on the resource data, each of the one or more third entities having the second base key, the first entity being configured to:

(a) receive the request from the one of the third entities;
(b) receive a digital signature from the third entity from which the request was received, the digital signature having been generated by the third entity signing at least part of the request using the second variant key;
(c) verify the at least part of the request by digitally signing at least part of the request using the second variant key and comparing the produced signature against the signature received in (g).

1495. A first entity according to claim 1494, wherein the second and third entities have different permissions in relation to the operations they can perform on the resource data, the permissions being defined based which of the first and second base key and variant key combinations is used for the verification.

1496. A first entity according to claim 1495, wherein the first base and variant key combination provides a higher permission to perform an operation on the resource data than the second base key and variant key combination.

1497. A first entity according to claim 1478,wherein the resource data represents a physical property.

1498. A first entity according to claim 1497, wherein the physical property is a remaining amount of a physical resource.

1499. A first entity according to claim 1498, wherein the resource is a consumable resource.

1500. A first entity according to claim 1499, wherein the resource entity is physically attached to a reservoir or magazine that holds the consumable resource.

1501. A first entity according to claim 1500, wherein the resource is a fluid.

1502. A first entity according to claim 1501, wherein the fluid is ink.

1503. A first entity according to claim 1485,wherein the operation includes a read, in which the resource data is read by the entity making the request.

1504. A first entity according to claim 1478,wherein the operation includes write, in which the resource data is modified by the entity making the request.

1505. A first entity according to claim 1478,wherein the operation includes decrementing, in which the resource is decremented by the entity making the request.

1506. A first entity according to claim 1478,wherein the one way function is a hash function.

1507. A first entity according to claim 1506, wherein the one way function is SHA1.

1508. A second entity configured for use with the first entity of claim 1523.

1509. A second entity configured for use with the first entity of claim 1526.

1510. A second entity configured for use with the first entity of claim 1536.

1511. A third entity configured for use with the first entity of claim 1528.

1512. A third entity configured for use with the first entity of claim 1530.

1513. A third entity configured for use with the first entity of claim 1537.

1514. A first entity according to claim 1478,configured to authenticate a digital signature supplied by a second entity, wherein one of the entities includes a base key and the other of the entities includes a variant key and a bit-pattern, the variant key being based on the result of applying a one way function to the base key and the bit-pattern, the digital signature having been generated by the second entity using its key to digitally signing at least part of data to be authenticated, the first entity being configured to:
(a) receive the digital signature from the second entity;
(b) receive the data; and (c) authenticate the digital signature based on the received data and the first entity's key.

1515. A first entity according to claim 1478,configured to implement a method of enabling or disabling a verification process of a first entity in response to a predetermined event, the first entity having at least one associated bit-pattern and at least one variant key, each of the variant keys having been generated by applying a one way function to: a base key; and one or more of the at least one bit-patterns, respectively; or one or more alternative bit patterns, each of the alternative bit-patterns being based on one or the at least one bit-patterns, the method including the method including:
(a) determining that the predetermined event has happened; and (b) enabling or disabling at least one of the first variant keys in response the predetermined event.

1516. A first entity according to claim 1478,configured for usein a system for enabling authenticated communication between a first entity and at least one other entity, the system including a second entity, wherein:
the first entity and the second entity share transport keys; and the second entity includes at least one authentication key configured to be transported from the second entity to the first entity using the transport keys, the authentication key being usable to enable the authenticated communication by the first entity.

1517. A first entity according to claim 1478,configured to implement a method of storing a first bit-pattern in non-volatile memory of a device, the method comprising:
(a) applying a one way function to a second bit-pattern associated with the device, thereby to generate a first result;
(b) applying a second function to the first result and the first bit-pattern, thereby to generate a second result;
and (c) storing the second result in the memory, thereby indirectly storing the first bit-pattern.

1518. A first entity according to claim 1478,configured to implement a method of storing a bit-pattern in each of a plurality of devices, each of the devices having a memory, the method comprising, for each device:
(a) determining a first memory location; and (b) storing the bit-pattern at the first memory location; wherein the first memory locations are different in at least a plurality of the respective devices.

1519. A first entity according to claim 1478,configured to implement a method of storing at least one functionally identical code segment in each of a plurality of devices, each of the devices having a memory, the method comprising, for each device:
(a) determining a first memory location; and (b) storing a first of the at least one code segments in the memory at the first memory location; wherein the first memory location is different in at least a plurality of the respective devices.

1520. A first entity according to claim 1478,configured to implement a method for providing a sequence of nonces (R0, R1, R2, ... ) commencing with a current seed of a sequence of seeds (x1, x2, x3,...), the method comprising:
(a) applying a one-way function to the current seed, thereby to generate a current nonce; (b) outputting the current nonce;

(b) using the current seed to generate a next seed in a sequence of seeds, the seed so generated becoming the current seed; and (c) repeating steps (a) to (c) as required to generate further nonces in the sequence of nonces.

1521. A first entity according to claim 1478,configured to implement a method of storing multiple first bit-patterns in non-volatile memory of a device, the method comprising, for each of the first bit-patterns to be stored:
(a) applying a one way function to a third bit-pattern based on a second bit-pattern associated with the device, thereby to generate a first result;
(b) applying a second function to the first result and the first bit-pattern, thereby to generate a second result;
and (c) storing the second result in the memory, thereby indirectly storing the first bit-pattern; wherein the third bit-patterns used for the respective first bit-patterns are relatively unique compared to each other.

1522. A method of enabling or disabling a verification process of a first entity in response to a predetermined event, the first entity having at least one associated bit-pattern and at least one variant key, each of the variant keys having been generated by applying a one way function to: a base key; and one or more of the at least one bit-patterns, respectively; or one or more alternative bit patterns, each of the alternative bit-patterns being based on one or the at least one bit-patterns, the method including the method including:
(a) determining that the predetermined event has happened; and (b) enabling or disabling at least one of the first variant keys in response the predetermined event.

1523. A method according to claim 1522, wherein step (a) includes disabling at least one of the variant keys, such that the disabled at least one variant key can no longer be used to digitally sign information in that entity.

1524. A method according to claim 1522, wherein step (a) includes disabling at least one of the variant keys, such that the disabled at least one variant key can no longer be used to verify information signed by one or more respective base keys related to the disabled at least one variant key in that entity.

1525. A method according to claim 1522, wherein the step of disabling the at least one variant key includes modifying a status of a flag associated with that at least one variant key.

1526. A method according to claim 1522, wherein the step of disabling the at least one variant key includes deleting that at least one variant key.

1527. A method according to claim 1522, wherein the step of disabling the at least one variant key includes modifying that at least one variant key 1528. A method according to claim 1522, wherein the event is a predetermined point in time being reached or passed.

1529. A method according to claim 1522, wherein the first entity includes a plurality of the variant keys, the plurality of variant keys being based on the result of a one way function applied to: a respective one of a corresponding plurality of base keys; and one of the at least one bit-patterns or one of the at least one alternative bit-patterns, the method including the steps of:
determining that a predetermined event related to one of the variant keys has happened; and enabling or disabling at least one of the plurality of variant keys with which the predetermined event is associated.

1530. A method according to claim 1522, wherein the plurality of base keys has a corresponding sequence of predetermined events associated with them, the method including the steps of:
(a) determining that one of the predetermined event has happened; and (b) enabling or disabling the variant key in the sequence corresponding to predetermined event that is determined to have happened.

1531. A method according to claim 1530, wherein the variant keys are disabled in the order of the sequence of predetermined events.

1532. A method according to claim 1531, wherein the sequence of events is chronological.

1533. A method according to claim 1532, wherein each of the events includes a time being reached.

1534. A method according to claim 1533, wherein the step of determining that one of the events has happened includes receiving a time from a trusted source.

1535. A method according to claim 1534, wherein the time is a date.

1536. A method according to claim 1535, wherein the date is determined with a resolution of a month.

1537. A method according to claim 1523, wherein the predetermined event includes detection of compromise of one or more of the keys, the method including disabling the one or more variant keys corresponding to the one or more keys that were compromised.

1538. A method according to claim to claim 1523, wherein the predetermined event includes suspect compromise of one or more of the keys, the method including disabling the one or more variant keys corresponding to the one or more keys that were suspected of being compromised.

1539. A method of manufacturing second entities for use in the verification process with the first entity of claim 1522, each of the first entities including at least first and second variant key, the first variant key having been generated by applying a one way function to a first base key and a first bit-pattern, and the second variant key having been generated by applying a one way function to a second base key and a second bit-pattern, the method comprising the steps of:
manufacturing a plurality of second entities for use with the first entities, each of the second entities including at least the first base key; and upon the first variant key being disabled in response to one of the predetermined event, manufacturing a plurality of third entities for use with the first entities, each of the third entities including at least the second base key.

1540. A method according to claim 1522, wherein the first variant key is automatically disabled in response to a predetermined event.

1541. A method according to claim 1540, further including the step of causing the first variant key to be disabled.

1542. A method according to claim 1541, wherein the first variant key is disabled in response to a time being reached.

1543. A method according to claim 1537, wherein at least some of the first entities have one or more further variant keys, each of the respective further variant keys having been generated by applying a one way function to respective further base keys and bit-patterns, each of the variant keys being enabled or disabled in response to respective predetermined events, the method comprising the step of manufacturing a sequence of sets of second entities, each set of the second entities being manufactured such that the variant key corresponding to its base key is enabled for the verification process during the life of that set.

1544. A method according to claim 1543, wherein the predetermined events are selected such that the variant keys corresponding with the base keys of more than one of the sets are enabled at once.

1545. A method according to claim 1522, using a first entity configured to authenticate a digital signature supplied by a second entity, wherein one of the entities includes a base key and the other of the entities includes a variant key and a bit-pattern, the variant key being based on the result of applying a one way function to the base
CA002639307A 2004-05-27 2004-05-27 Method for at least partially compensating for errors in ink dot placement due to erroneous rotational displacement Abandoned CA2639307A1 (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
CA2716065A CA2716065A1 (en) 2004-05-27 2004-05-27 Method for at least partially compensating for erros in ink dot placement due to erroneous rotational displacement
CA2716810A CA2716810A1 (en) 2004-05-27 2004-05-27 Method for at least partially compensating for errors in ink dot placement due to erroneous rotational displacement
CA2716778A CA2716778A1 (en) 2004-05-27 2004-05-27 A printer comprising two uneven printhead modules
CA2716853A CA2716853A1 (en) 2004-05-27 2004-05-27 Method for at least partially compensating for errors in ink dot placement due to erroneous rotational displacement
CA002639307A CA2639307A1 (en) 2004-05-27 2004-05-27 Method for at least partially compensating for errors in ink dot placement due to erroneous rotational displacement

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CA002567724A CA2567724A1 (en) 2004-05-27 2004-05-27 Method for at least partially compensating for errors in ink dot placement due to erroneous rotational displacement
CA002639307A CA2639307A1 (en) 2004-05-27 2004-05-27 Method for at least partially compensating for errors in ink dot placement due to erroneous rotational displacement

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CA002567724A Division CA2567724A1 (en) 2004-05-27 2004-05-27 Method for at least partially compensating for errors in ink dot placement due to erroneous rotational displacement

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CA2716853A Division CA2716853A1 (en) 2004-05-27 2004-05-27 Method for at least partially compensating for errors in ink dot placement due to erroneous rotational displacement
CA2716778A Division CA2716778A1 (en) 2004-05-27 2004-05-27 A printer comprising two uneven printhead modules
CA2716065A Division CA2716065A1 (en) 2004-05-27 2004-05-27 Method for at least partially compensating for erros in ink dot placement due to erroneous rotational displacement
CA2716810A Division CA2716810A1 (en) 2004-05-27 2004-05-27 Method for at least partially compensating for errors in ink dot placement due to erroneous rotational displacement

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CA002639307A Abandoned CA2639307A1 (en) 2004-05-27 2004-05-27 Method for at least partially compensating for errors in ink dot placement due to erroneous rotational displacement
CA2716778A Abandoned CA2716778A1 (en) 2004-05-27 2004-05-27 A printer comprising two uneven printhead modules
CA2716065A Abandoned CA2716065A1 (en) 2004-05-27 2004-05-27 Method for at least partially compensating for erros in ink dot placement due to erroneous rotational displacement
CA2716810A Withdrawn CA2716810A1 (en) 2004-05-27 2004-05-27 Method for at least partially compensating for errors in ink dot placement due to erroneous rotational displacement
CA2716853A Abandoned CA2716853A1 (en) 2004-05-27 2004-05-27 Method for at least partially compensating for errors in ink dot placement due to erroneous rotational displacement

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CA2716778A Abandoned CA2716778A1 (en) 2004-05-27 2004-05-27 A printer comprising two uneven printhead modules
CA2716065A Abandoned CA2716065A1 (en) 2004-05-27 2004-05-27 Method for at least partially compensating for erros in ink dot placement due to erroneous rotational displacement
CA2716810A Withdrawn CA2716810A1 (en) 2004-05-27 2004-05-27 Method for at least partially compensating for errors in ink dot placement due to erroneous rotational displacement
CA2716853A Abandoned CA2716853A1 (en) 2004-05-27 2004-05-27 Method for at least partially compensating for errors in ink dot placement due to erroneous rotational displacement

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