WO2016020926A1

WO2016020926A1 - System and method for variable incrementing of printer carriage movement

Info

Publication number: WO2016020926A1
Application number: PCT/IL2015/050811
Authority: WO
Inventors: Ophir Shlomo CHERNIN; Jonathan STEIN; Tuvia Elbaum; Leon ROSENGARTEN; Moshe Zuckerman
Original assignee: Zuta Labs Ltd.
Priority date: 2014-08-08
Filing date: 2015-08-09
Publication date: 2016-02-11

Abstract

A system and method for determining a placement of an autonomous printing device on a substrate to be printed and for varying an incrementing distance of an autonomous printing device upon a detection that a newly estimated location of the device is different than a prior estimated location of the device. An incrementing may be varied to accommodate one or more printing positions on a swath to be printed in light of the newly estimated location. An incrementing may be varied on one or more of an x-axis or y-axis movement. Further disclosed are a system and method for inserting a print head cartridge into an aperture on a ventral side of a printing device, where upon such insertion, the cartridge is held in a cavity located dorsally from the aperture, and the print nozzles of the cartridge are directed toward the substrate.

Description

SYSTEM AND METHOD FOR VARIABLE INCREMENTING OF PRINTER CARRIAGE MOVEMENT

BACKGROUND OF THE INVENTION [001] The apparatus or structure that carries or moves a print-head along or above a substrate to be printed is generally moved in fixed increments. For example, when printing a page of graphics or text, a print carriage may advance a print-head in fixed increments on the y-axis in, for example, a print swath height (height of print-head nozzle array). An error in an increment of advancing the page to be printed may, therefore, not correctable in the course of printing the page since the advancement increments are dictated by the print-head geometry. Similarly, movement of a print-head carriage along an x-axis is typically included in the print instructions so that errors in x-axis advancing or in skew (rotational movement of the print-head relative to the substrate) may not be correctable in a given print swath.

SUMMARY OF THE INVENTION

[002] Embodiments of the present invention comprise a system and method for determining a placement of an autonomous printing device on a substrate to be printed and for varying an incrementing distance of an autonomous printing device upon a detection that a newly estimated location of the device is different than a prior estimated location of the device. An incrementing may be varied to accommodate one or more printing positions on a swath to be printed in light of the newly estimated location. An incrementing may be varied on one or more of an x-axis or y-axis movement. Further disclosed are a system and method for inserting a print head cartridge into an aperture on a ventral side of a printing device, where upon such insertion, the cartridge is held in a cavity located dorsally from the aperture, and the print nozzles of the cartridge are directed toward the substrate.

[003] According to one embodiment, an autonomous print carriage system according to the present invention may comprise: a print head; at least one sensor; a processor; an actuator; and at least one wheel. The sensor may be configured to detect a location of the autonomous print carriage on a substrate to be printed. The processor may be configured to calculate a location on the substrate for printing of a mark by the print head; and to issue a signal to the actuator to vary an increment of an advance of the at least one wheel so that upon the wheel executing of the varied increment, the print head may be above the location for the printing of the mark.

[004] According to some embodiments, the processor may be configured to calculate the varied increment by comparing the location on the substrate for printing of the mark to an expected location of the print head after an unvaried increment of the at least one wheel. The processor may be configured to calculate a size of a plurality of varied increments for advancing the at least one wheel, the size determined by interpolating a number of unvaried increments into a number of characters remaining to be printed on a line on the substrate to be printed. According to one embodiment, the increments may be along an x axis. According to another embodiment, the increments may be along a y axis.

[005] According to some embodiments, the processor may be configured to calculate the location on the substrate for printing the mark relative to the location of the autonomous print carriage on the substrate. The processor may further be configured to compare a stored coordinate of the location of the carriage on the substrate, to a corrected location of the carriage on the substrate. According to some embodiments, the processor may be configured to calculate the corrected location from inputs received from a plurality of the at least one sensors. The processor, according to some embodiments, may be configured to vary a size of the mark to be printed from a size of the mark that was transmitted to the system.

[006] An autonomous printing carriage, according to some embodiments may comprise at least one indicator visible from outside of the autonomous printing carriage, the indicator may be aligned with a position of a print head of the autonomous printing carriage. According to some embodiments, the at least one indicator may comprise a first indicator, and a second indicator, the first indicator on a first side of the autonomous printing carriage, and the second indicator on a second side of the autonomous printing carriage, wherein an imaginary line intersecting the first and the second indicators indicates the position of the print head. According to other embodiments, at least one indicator comprises a light to illuminate a position on a substrate to be printed, the position aligned with the printing head.

1007] According to one embodiment, the at least one indicator may comprise a first indicator, and a second indicator, the first indicator on a first side of the autonomous printing carriage, and the second indicator on a second side of the autonomous printing carriage, wherein an imaginary line connecting the first indicator and the second indicator align a lateral position of the print head. According to another embodiment, an imaginary line connecting the first indicator and the second indicator align a vertical position of the starting point of the printing.

[008] An autonomous printing device according to some embodiments may comprise an aperture on a ventral side of the device through which a print cartridge is insertable into the autonomous printing device. The aperture is configured to accommodate said print cartridge held by a print head carrier. The printing device may comprise a print cartridge carrier configured to be held in a cavity located dorsally to the aperture, the carrier may be configured to hold the print cartridge upon its insertion through the aperture. The printing device may comprise an openable cover of the aperture.

[009] According to some embodiments, the printing device may comprise a cavity dorsal to the aperture, the cavity configured to contain the print cartridge upon the insertion, an underside of the cavity including a cover configured to cover the cartridge upon its insertion into the device. According to some embodiments, the print nozzles of the print cartridge may protrude through the aperture into which the cartridge is insertable. [010] A method of varying a width of an incrementing movement of an autonomous printer according to some embodiments, may comprising: altering by a processor, an estimate of a current position on a substrate to be printed of a print head of an autonomous printer from a first current estimated position to a second current estimated position; calculating by the processor a width of a fixed number of printing positions using the first current estimated position; calculating by the processor a width of the number of printing positions using the second estimated position; and varying a distance of an incrementing movement of the printer on the substrate from the first width to the second width. According to some embodiments the method may further comprise varying a dimension of a character to be printed in a first of the fixed number of printing positions. According to some embodiments the method may further comprise interpolating a number of unvaried increments into a number of printing positions that remain to be printed on a line. According to one embodiment the incrementing movement may comprise a movement along an x-axis of the substrate to be printed.

[011] According to some embodiments a method for correcting a rotational misalignment of a printing by an autonomous printing device may comprise: incrementing a first movement of an autonomous printing device along a y-axis of a substrate to be printed by a first distance; detecting a rotational misalignment of a printing by the autonomous printing device of a swath; and incrementing a second movement of the autonomous printing device along the y-axis of the substrate to be printed by a second distance. According to some embodiments, the second distance is less than the first distance, the method may further comprise, following the second incrementing, aligning a print head of the autonomous printing device over a portion of the swath. The method, according to some embodiments may comprise following the second incrementing, printing on at least one printing position of the swath that is offset from a printing on said printing position of said swath prior to said second incrementing. Some embodiments of the method may further comprise repeating a printing in at least one printing position on the swath following the second incrementing; and, offsetting in the repeating of the printing on the at least one printing position an alignment of the repeated printing. The swath, according to some embodiments, may comprise a first swath printed before the second movement and the method according to some embodiments may comprise offsetting a printing on at least one printing position of second swath relative to the at least one position of the first swath.

[012] A method of selecting a placement on a substrate of an autonomous printing carriage, may comprise, according to some embodiments, aligning an indicator of the carriage, the indicator visible on an outside of the autonomous printing carriage, with a position on the substrate to be printed at a start of a printing task. The indicator may comprise, according to some embodiments, a first indicator, and embodiments of the method may comprise aligning the position on the substrate with an imaginary intersecting line of the first indicator and a second visible indicator on the autonomous printing carriage. According to another embodiment, the indicator may comprise a first indicator, and the method may comprise aligning of the position on the substrate with an imaginary connecting line from the first indicator to a second visible indicator on the autonomous printing carriage. Aligning the indicator may comprise aligning a light emitted from the indicator with the position on the substrate.

[013] According to one embodiment, a method of inserting a print cartridge into an autonomous printing device may comprise inserting the print cartridge through a ventral aperture in the autonomous printing device. The method may further comprise inserting the print cartridge into a print cartridge carrier, the print cartridge carrier held in a cavity of the autonomous device, the cavity dorsal to the aperture. According to one embodiment, the method may further comprise opening a cover of the aperture, the opening to expose a print nozzle of the print cartridge. According to some embodiments the method may comprise closing the cover, the cover configured to retract the print nozzle upon the closure. In yet another embodiment, the method may further comprise compressing a spring in a cavity of the autonomous printing device, upon the insertion of the print cartridge; and decompressing the spring upon an extraction of the print cartridge from the cavity. According to some embodiments the method may further comprise opening a cover of the aperture upon an initiation of a printing by the autonomous printing device; and closing the cover upon a completion of the printing.

BRIEF DESCRIPTION OF THE DRAWINGS

[014] The subject matter regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, both as to organization and method of operation, together with objects, features, and advantages thereof, may best be understood by reference to the following detailed description when read with the accompanying drawings in which:

Fig. 1A is a schematic drawing of an autonomous print carriage in accordance with an embodiment of the invention;

Fig IB is a diagram of position increments and partial increments in accordance with an embodiment of the invention;

Fig. 2 is a flow diagram of a method in accordance with an embodiment of the invention;

Fig. 3 is a flow diagram of a method in accordance with an embodiment of the invention;

Figs. 4A and 4B are illustrations of an alignment of a printing carriage on a substrate to be printed in accordance with embodiments of the invention;

Fig. 5 is a flow diagram of a method in accordance with an embodiment of the invention;

Figs. 6 is a schematic view of a print head and print head carrier unit of an autonomous printing device in accordance with an embodiment of the invention;

Fig. 7 is a schematic diagram of a cover of an aperture in a ventral side of a printing carriage in accordance with an embodiment of the invention;;

Fig. 8 is a cut-away top view of a printing device with a recessing holder to hold a carrier or cartridge in the printing carriage, in accordance with an embodiment of the invention; and

Fig. 9 is a flow diagram in accordance with an embodiment of the invention. [015] It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE PRESENT INVENTION

[016] In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. In other instances, well- known methods, procedures, and components have not been described in detail so as not to obscure the present invention.

[017] Although embodiments of the invention are not limited in this regard, discussions utilizing terms such as, for example, "processing," "computing," "calculating," "determining," "establishing", "analyzing", "checking", or the like, may refer to operation(s) and/or process(es) of a computer, a computing platform, a computing system, or other electronic computing device, that manipulates and/or transforms data represented as physical (e.g., electronic) quantities within the computer's registers and/or memories into other data similarly represented as physical quantities within the computer's registers and/or memories or other information non-transitory storage medium that may store instructions to perform operations and/or processes. Although embodiments of the invention are not limited in this regard, the terms "plurality" and "a plurality" as used herein may include, for example, "multiple" or "two or more". The terms "plurality" or "a plurality" may be used throughout the specification to describe two or more components, devices, elements, units, parameters, or the like. The term set when used herein may include one or more items. Unless explicitly stated, the method embodiments described herein are not constrained to a particular order or sequence. Additionally, some of the described method embodiments or elements thereof can occur or be performed simultaneously, at the same point in time, or concurrently.

[018] As used in this application and in addition to the regular meanings, the following terms may include the attributes and definitions listed below: "increment" may mean the advancing or retreating of a wheel or other propulsion mechanism of a device either over a given period or rate, or in an absolute measure. In some embodiments, an incrementing of a wheel and propulsion of a carriage may by default proceed or move along an axis at fixed increments. In some embodiments a signal may instruct a wheel or propulsion system to move in such fixed increments along an axis until a stop signal is received. A varied increment may, in addition to its regular meaning, mean a change in a width or size of an increment along an axis. The term "swath" may refer to a pass or movement of a printer such as an autonomous printing device over an area such as a line on a substrate to be printed. In some embodiments, a printer may make one or more passes over some or all parts of a swath, or may make an overlapped pass over one or more swaths so that a print head passes over a portion of a first swath and a portion of a second swath. The term "dither" may refer to a process of varying dot colors, such as black and white dots over different areas of a mark to be printed. For example a first area of a mark to be printed may have a first concentration of black and white dots, while a second area of a mark to be printed may have a second concentration of black and white dots. In some embodiments, a dithered area may have blurred or less defined edges than an undithered mark.

[019] Some embodiments of the invention may include a system and method for varying an incrementing rate, spacing or movement of a print carriage. Reference is made to Fig. 1, an open, top- view, schematic drawing of an autonomous print carriage system 100 in accordance with an embodiment of the invention. Autonomous print carriage system 100 may include a print carriage such as a self-propelled carriage 102 that is not fixed to a standing structure and that is not wired (i.e. wireless) or connected by wire to an external power source or data source (i.e. is free from any wire connection to an external power or data source). Carriage 102 may include one or more print heads 104, one or more actuators 106 such as electric motors that may drive one or more wheels 118 or sets of wheels configured to propel, locomote or move carriage 102 over a substrate to be printed such a sheet of paper 108, one or more onboard optical or other sensors 110 and/or stationary sensors 120 such as may detect a presence of a paper 108, an edge of paper 108, a paper- edge indicator or holder, or a printed (or otherwise attached - such as a sticker) mark 112, such as text, graphics or other items to be printed, on paper 108. Carriage 102 may also include for example, a power source 114, a wireless communication unit 115 and other components. Carriage 102 may also include one or more processors 116, power sources 101 and memory units 117. In some embodiments, carriage 102 may be propelled by one or more sets of wheels 118, such as for example a set of wheels 118 that may propel carriage along an x-axis, and a set of wheels 118 that may propel carriage along a y-axis. Carriage 102 may include one, two, three or more visible indicators 119A, 119B, 119C and 119D that may be located for example on opposing sides of carriage 102.

[020] In operation of some embodiments, carriage 102 may receive a signal such as a wireless signal from a remote device that includes an instruction to print one or more marks 112 at one or more locations on paper 108. Carriage 102 may proceed to move along paper 108 to print marks 112. For example, for printing text, carriage 102 may move along x-axis swaths to be printed in increments of ink dot diameters or half ink dot diameters. Upon printing a line on an x-axis, or at other times, carriage 102 may move from line-to-line (y-axis) in increments of single swath, fractional swath, etc. A row may include a swath of length x or a fraction of length x. Sensor 110 may detect and, for example, track a position of one or more of marks 112 on paper 108 as such marks 112 are printed, and may, for example, track an edge of paper 108 or other locations that may be used in location sensing of the carriage on paper 108. Sensor 110 may also detect relative motion along the substrate to be printed (such as paper 108), without actually tracking the position of actual marks. In some embodiments, such tracking may detect an uneven or inaccurate placement of mark 112 on a particular location of paper 108, a mis-alignment of a movement or positioning of head 104 over a desired location or coordinate on paper 108, a skewed movement of paper 108 or of carriage 102 on paper 108 or a miscalculation of a position of carriage 102 on for example an x length to be printed.

(021] For example, carriage 102 may include two or more movement, position or location sensors 110 and 111. At certain times, the location calculations produced by one or more of such sensors 110 may be determined, compared and reconciled, in for example multi-sensor fusion decision process. A determined location of carriage 102 after such reconciliation may differ from a determined position before such reconciliation. Carriage 102, or a processor 116 may issue a signal to propel carriage 102 in a distance equal to the difference between the determined position before such reconciliation, and the determined position after such reconciliation (such distance, the "reconciliation distance"). The reconciliation distance may in some cases be more than or less than a typical x-axis increment of carriage 102. In some embodiments, the reconciliation distance may be added to or subtracted from a typical x-axis increment 120 so that the reconciliation distance is accounted for as part of an upcoming x-axis increment rather than as a separate increment. In some embodiments, a partial or variable increment 122 may allow implementation of the reconciliation distance in the course of a printing swath, and without stopping the movement of carriage 102. In some embodiments, an increment 120 may be less than the width of a letter or mark to be printed such that there may be several or many increments 120 or printing positions in the space occupied by a single printed letter or mark.

[022] By way of example, in some embodiments, in the course of a printing pass on an x-axis, processor 116, may wrongly believe or determine that there are five character spaces or printing positions remaining on a line to be printed and five characters remaining to be printed on such line. A reconciliation of one or more sensors 110 may be performed, and may indicate that there are four spaces or position increments rather than five spaces left on the line to be printed. In some embodiments, processor 116 may interpolate the space required for printing such five characters into the actually-remaining four spaces that are available on such line. The length (on the x-axis) of one or more of such five characters may be shortened to fit into the remaining four spaces, and the increments of carriage 102 may be varied or reduced in one or more of such remaining spaces so that carriage 102 is incremented five time in such four spaces. In some embodiments, the height of the characters may be retained, even though the length of the characters may be reduced to fit into the shrunken character spaces. A reverse interpolation and lengthening of characters may be implemented if the reconciled location indicates that there are more, rather than fewer, printing positions remaining on a line to be printed. In such case, rather than skip a printing position, processor 116 may recalculate and increase a width of one or more remaining printing positions. [023] In some embodiments, a varied increment may be implemented for a movement of carriage 102 along a y-axis. For example, carriage 102 may advance a total of 3 mm on a y-axis between each line to be printed, and such advance may be implemented in three increments 124 of 1 mm each. At one or more periods during an advancing of carriage 102 on the y-axis (e.g. advancing in the vertical direction), one or more sensors 110 may indicate that there was a misalignment of one or more of the distance or pitch of a prior line that was printed, or that one or more prior increments was more or less than 1 mm. In response, processor 116 may instruct one or more wheels 118 to move in increments 125 of more or less than 1 mm so that the actual advancing of carriage 102 along the y-axis is the desired 3 mm.

[024] In some embodiments, such as when an adjustment is required in a pitch or angle of carriage 102 to a page or to the lines that were already printed, a partial increment along an x-axis may be made at or near a time of an increment along a y-axis, so that carriage 102 partially pivots around its own vertical axis 126 to adjust or reorient its position and angle relative to the angle of previously printed lines.

[025] In one or more increments of movements of carriage 102 on paper 108, a position of head 104 may be moved so that there is an overlap of some or all of a current position or coordinate of head 104 with a past, previous or prior position or coordinate of head 104 on paper 108. In some embodiments, an overlap of a current position of head 104 with a prior position may be programed or signaled on a periodic basis. In some embodiments, an overlap may be executed upon a signal from for example sensor 110 that there has been or will be for example an error or inaccurate placement of a mark 112 on paper 108, or that a movement of carriage 102 or paper 108 has resulted in a skewed orientation of paper 108 relative to a movement of carriage 102.

[026] In some embodiments, a size or extent of an overlap of a placement of head 104 in a current position relative to a prior position may be varied in response for example to a detected mis-location of a mark 112, or in response to a detected skew or misalignment in paper 108 relative to carriage 102. In some embodiments, an initiation of an overlap or an extent of an overlap may be dictated or signaled not (or not only) by an instruction from a print-file, but by carriage 102 or sensor 110, that detected or indicates that one or more marks 112 has been or will be misplaced or that there has been a skew in an orientation of carriage 102 relative to paper 108.

[027] In some embodiments, an overlap of a printed mark 112 may allow a re-alignment of the printed mark 112 or of a portion of the printed mark 112 so that at least a portion of the misprint may be corrected. In some embodiments, the overlap may be on a movement along an x-axis. In some embodiments, the overlap may be along a y-axis.

[028] The position information from one or more sensors 110 may be used by processor(s) 116 to calculate a misalignment, and update a next or subsequent print instruction. In some instances, this may be within the current swath; in others, it may be in a following swath(s). Processor(s) 116 may calculate misalignment correction (rotation and/or translation) to the rasterization of the information to be printed. In some embodiments, this correction may be updated prior to firing of the print-head nozzles. The system may have a threshold below which the error is not compensated. The system may have a threshold above which the error is dealt with in a different manner (for example, a gap in printing and realignment of the rasterization) if the error is too large to correct.

[029] In some embodiments, carriage 102 and print head 104 do not advance a full line or increment on the y-axis, but rather allow some overlap between a line printed and the increment to a next line. In such case, for example, head 104 may not print the top row of dots on the incremented line, to align the current and the prior line.

[030] In some embodiments, a bottom line or lines of dots or marks of a printing swath may be dithered, half-toned or set off in a second printing on the swath so that such bottom line of dots are reprinted in the second pass of the printer over the swath at a slightly offset position from the printing in the first pass of the printer over the swath. In some embodiments, a top line a next swath may also be dithered so that two dithered set of dots are mated to produce a relatively clean line and to blur the border between the swaths.

[031] In some embodiments, a printing of a line may be repeated with a slight offset on the overprinting between the repeated swaths. In some cases carriage 102 may make a tiny (such as for example .1 to .5 mm) increment along a y-axis and repeat a movement over a swath, without actually reprinting over such repeated swath.

[032] In some embodiments, processor or processors 116 may calculate the dimensions, width or distance of the varied increment by comparing the location on the substrate of the mark to be printed, to an expected location that print head 104 will be after an unvaried increment of wheel(s) 118.

[033] In some embodiments, processor(s) 116 may calculate a size of two or more varied increments for advancing wheel 118, where the size of one or more of the varied increments is determined by interpolating a number of unvaried increments into a number of printing positions that remain to be printed on a line or swath of the substrate.

[034] In some embodiments, processor(s) 116 may calculate a location on the substrate for printing mark 112 relative to the location of print head 104 or print carriage 102 on the page 108 to be printed.

[035] In some embodiments, processor 116 may compare a stored coordinate of the location of carriage 102 on the substrate that may have been determined by a first sensor 110, to a corrected location of carriage 102 on the substrate that may have been determined by a second sensor 110 or by a combination or other calculation of information from sensors 110 and/or 120.

[036] In some embodiments, processor or processors 116 may calculate a size of mark 112 to be printed, and such size may be varied from a size of mark 112 that was transmitted to carriage 102, so that the size to be printed is different than the size of other characters or marks to be printed. The varied size of the character or mark 112 may accommodate the varied size of the increment or the space in which mark 112 is to be printed. [037] In some embodiments, an increment may move carriage 102 along a y-axis of the substrate to be printed.

[038] Reference is made to Fig. 2, a flow diagram in accordance with an embodiment of the invention. In block 200, embodiments of a method may include altering an estimate of a current position on a substrate to be printed of a print head of an autonomous printer from a first current estimated position to a second current estimated position. In block 202, an embodiment of the method may calculate a width of a fixed number of characters or printing positions, such as a number of printing positions remained on a line being printed using the first current estimated position. In block 204, an embodiment of the method may calculate a width of the number of characters or printing positions using the second estimated position. In block 206, an embodiment of the method may vary a distance, length, width or size of an incrementing movement of the printer on the substrate from the first width to the second width. In some embodiments, varied increments may be applied to a movement of the printed along an x-axis of the substrate to be printed.

[039] In some embodiments, a dimension of one or more characters, such as a width, height or other dimensions of the character to be printed may be varied so that the character's dimensions match or conform to the varied size of the printed position into which it is to be printed.

[040] In some embodiments, a number of unvaried increments may be interpolated into a number of varied increments as part of determining a width of the varied increments.

[041] Reference is made to Fig. 3, a flow diagram in accordance with an embodiment of the invention. In some embodiments a method may correct a rotational misalignment of a printing by an autonomous printing device . In block 300, a processor may issue a signal to increment by a first distance a position of an autonomous printing device along a y-axis of a substrate to be printed. In block 302, there may be detected a misalignment of a printing by the printing device. In some embodiments, the misalignment may be between a swath that was printed after the first incrementing and a swath that was or is to be printed after the second incrementing. In block 304, the position of the printing device may be incremented along the y-axis by a second distance.

[042] In some embodiments the distance of the first incrementing may be less than, or alternatively, more than, the distance of the second incrementing. In some embodiments, after the second incrementing, a print head of the printing device may be aligned so that it is over a portion, some or all of the swath that was printed before the second incrementing. In some embodiments, after the second incrementing, the printing device may print on at least a portion of a printing position of the swath on which it had already printed prior to the second incrementing, but where in such repeated printing the position of the print head or of dots or marks made on such position is offset from the marks made prior to the second incrementing.

[043] Reference is made to Figs. 4A, an illustration of an alignment of a printing carriage 102 on a substrate to be printed in accordance with an embodiment of the invention. In operation, a user may align a position of carriage 102 for a start point of a print task at an imaginary line or intersection of indicators 119A and 119B. Indicators 119 may be or may include one or more of edges, indentations, grooves, bumps, lines or other visible indicators at or on an outside of carriage 102 that may be visible on an outside of carriage 102 to a user who is placing carriage 102 onto a substrate such as paper 108 to be printed. Indicators 119 may be aligned with a position of print head 104 (such as, for example, a specific predefined edge of print head 104, a corner of print head 104 or the like) that may not be visible from an outside of carriage 102 when carriage 102 is positioned for printing on a substrate to be printed. By imagining or estimating an intersection point of indicators 119A and 119B which may be located on opposing sides of carriage 102, a user may estimate a desired start-point of print head 104 for the upcoming print task. In some embodiments, indicator 119B may be used in conjunction with indicator 119C to find or estimate for example a lateral (i.e. along the x-axis) position of a start point for a printing task, and/or of a portion of print head 104, such as, for example, a lateral edge of head 104, and indicators 119B and 119D may be used to estimate or find a vertical (i.e. along the y-axis) start point for a printing task and/or of a portion of print head 104, such as, for example, a vertical edge of head 104 . In some embodiments, a user may for example align indicator 119B with for example a payee line of a check as a start position for a printing of the check. Aligning, in the context of the present invention may refer to bringing an indicator 119 (such as indicator 119B) or a portion of print head 104 to coincide with a start point for a printing task (e.g. to be placed substantially above the start point). Aligning may further refer to coinciding an imaginary line connecting two indicators located on opposite sides of carriage 102, such as indicators 119A and 119D (in Fig. 4A), with a start point for a printing task in a first axis (e.g. in the vertical axis) and coinciding an imaginary line connecting another pair of opposite indicators, such as indicators 119B and 119C, with a start point for a printing task in a second axis (e,g. in the lateral axis).

[044] Reference is made to Fig. 4B, a schematic view of an autonomous print carriage in accordance with an embodiment of the invention. In some embodiments, one or more lights such as for example light emitting diodes (LED) 502A, 502B, 502C, 502D which may illuminate for example a position for placement of carriage 102 at a start of a printing job, where such position is aligned with a position of head 104. An LED 502 may be positioned on a side or under carriage 102 so that for example a point or line of light is visible which may project outward from carriage 102 at a point next to LED 502. The imaginary intersection of the lines or points of light created by LED 502B and 502D may allow a user to estimate a starting lateral position of print head 104, and an imaginary intersection of the points or lines of LED's 502A and 502C may allow a user to estimate a starting vertical position of print head 104.

[045] Reference is made to Fig. 5, a flow diagram in accordance with an embodiment of the invention. Embodiments of a method of the invention may include selecting a placement location or position on a substrate of an autonomous printing carriage. In block 600, an indicator that may be visible from an outside of the carriage may be aligned with a position on a substrate to be printed at a start of a printing task. The position may correspond to a location of a print head on the underside of the carriage. In some embodiments, a position of a print head may be located at an underside of the carriage that is below an intersection of an imaginary line connecting a first visible indicator and a second visible indicator on an opposite side of the carriage. The intersecting points of the opposing indicators may be used to estimate a lateral starting point of a printing job or a vertical starting point of a printing job.

[046] Reference is made to Figs. 6, a schematic view of a print head and print head carrier unit of an autonomous printing device in accordance with an embodiment of the invention. In some embodiments, a print head cartridge 700 may be fitted into a print head carrier 702 when the cartridge and carrier are still outside of the printing carriage, and the print head cartridge 700 as so fitted into the cartridge 702 may be inserted into the printing carriage from the ventral or underside of the printing device. It should be understood that all references to ventral, dorsal, underside, top, bottom and sides of the printer refers to when the printer is in operational position. For example, the ventral side of the printer is the side directed towards paper 108 when the printer is in operation, while the dorsal side of the printer is the side of the printer distant from paper 108 when the printer is in use. The carrier 702 and cartridge 700 may be held inside a cavity 705 that is located dorsally to the aperture 706 through which they are inserted into the printing carriage 102. The carrier 702 and cartridge 700 as so combined may be snapped into place and held in position inside the printing carriage 102 by a bracket 708 that may be fixed within the carriage 102.

[047] Reference is made to Fig 7, a schematic diagram of a cover cavity of a printing carriage in accordance with an embodiment of the invention. In some embodiments, the underside of the carriage 102 may include a cover 704, door or flap that may slide aside or be swung out to expose the cavity 705 within the carriage 102 that may contain carrier 702 and cartridge 700. The cover 704, door or flap may include a further aperture 710 that may leave exposed the print nozzles 703 of the print head 104, while still protecting the remainder of the cavity 705. In some embodiments, the cover 704, door or flap may cover and protect the print nozzles 703 when the device is not printing. The cover 704, door or flap may be swing or slid aside or otherwise opened, either automatically or manually by a user, to expose the print nozzles 703 for a printing task. In some embodiments, carrier 702, cartridge 700 or bracket 708 that holds the carrier 702 may retract upwards (dorsally) when the cover 704, door or flap is closed or by the closing of the door or flap, and may advance downward when cover 704, door or flap is opened so allow exposure to the paper or printing substrate to nozzles 703. In some embodiments, a spring 712 may be compressed when cover 704 is closed and may force cartridge 700 and nozzles 703 down through aperture 710 towards the ventral underside of the carriage 102 during a printing job, or that may present carrier 702 and cartridge 700 when cover 704 is opened. An inside or internal face 714 of cover 704 may include a raised outline or ridge 716 to support an area of the cartridge 700 around nozzles 703 so that the nozzles 703 protrude through cover 704 when it is open, but are not in contact with the cover 704. Cover 704 may also include a rubber or other seal which prevents leakage from the print nozzles 703 from exiting the cavity when the device is not printing.

[048] Reference is made to Fig. 8, a cut-away top view of a printing device with recessing holders or retracting bracket 900 to hold one or more of a carrier 702 or cartridge 700 in printing carriage 102. In some embodiments, one or more side of a bracket or holder of carrier 702 may recess or retract slightly during an insertion of carrier 702 or cartridge 700 to fit snugly around cartridge 700, and advance against or around cartridge 700 when insertion is complete to hold carrier 702 and cartridge 700 in a desired position. One or more springs or flexible fasteners 902 may allow such recessing and advancing. Once carrier 702 and cartridge 700 are clicked into position, recessed or retracting bracket or other object may advance into place to maintain or hold cartridge 700 in a desired position for printing.

[049] Reference is made to Fig. 9, a flow diagram of a method in accordance with an embodiment of the invention. In block 900, a method of an embodiment of the invention may include inserting a print cartridge into an autonomous printing device, by inserting the print cartridge through an aperture on the ventral side of the autonomous printing device. In some embodiments, during and following such insertion, the top or dorsal side of the cartridge is directed towards the top or dorsal side of the carriage and the nozzles of the print cartridge are pointed towards a ventral side of the carriage. In some embodiments, the print cartridge is held in a cavity of the printing device, there the cavity is located dorsally to the ventral aperture. In some embodiments, the ventral aperture may be configured with a door that may swing, slide or otherwise close over the aperture, for example to protect the nozzles of the cartridge when the device is not in use, and to open the aperture and expose the nozzles for printing. In some embodiments, an inside of the cover may include one or more ridges or elevated portions against which a portion of the cartridge may be pressed when the cover is closed, so that the cartridge is slightly retracted when the cover closes. One or more ridges on the inside of the cover may push against the ventral side of the cartridge to retract the nozzles into the cavity, while keeping a space between the cover and the nozzles of the cartridge so that the nozzles are held away from the closed cover. In some embodiments, the elevated portion of the cover may create a gasket to prevent ink from escaping from the device if ink leaks out of the cartridge. The nozzles may be slightly extended out of the aperture when the cover is open to present the nozzles to the substrate to be printed.

[050] In some embodiments, when the cartridge is pushed through the aperture into the cavity, a spring may be compressed, and the spring may decompress when the cartridge is removed to present the cartridge outside of the aperture.

[051] According to some embodiments, the method may comprise closing cover 704, cover 704 may be configured to retract print nozzle 703 upon closure.

[052] While certain features of the invention have been illustrated and described herein, many modifications, substitutions, changes, and equivalents will now occur to those of ordinary skill in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.

[053] Various embodiments have been presented. Each of these embodiments may of course include features from other embodiments presented, and embodiments not specifically described may include various features described herein.

Claims

1. An autonomous print carriage system comprising:

a print head;

at least one sensor;

a processor;

an actuator; and

at least one wheel;

wherein

said sensor is configured to detect a location of said autonomous print carriage on a substrate to be printed;

said processor is configured to calculate a location on said substrate for printing of a mark by said print head; and

said processor is configured to issue a signal to said actuator to vary an increment of an advance of said at least one wheel so that upon said wheel executing of said varied increment, said print head is above said location for said printing of said mark.

2. The system as in claim 1, wherein said processor is configured to calculate said varied increment by comparing said location on said substrate for printing of said mark to an expected location of said print head after an unvaried increment of said at least one wheel.

3. The system as in any one of claims 1 and 2, wherein said processor is configured to calculate a size of a plurality of varied increments for advancing said at least one wheel, said size determined by interpolating a number of unvaried increments into a number of characters remaining to be printed on a line on said substrate to be printed.

4. The system as in any one of the preceding claims, wherein said processor is configured to calculate said location on said substrate for printing said mark relative to said location of said autonomous print carriage on said substrate.

5. The system as in any one of the preceding claims, wherein said processor is configured to compare a stored coordinate of said location of said carriage on said substrate, to a corrected location of said carriage on said substrate.

6. The system as in claim 5, wherein said processor is configured to calculate said corrected location from inputs received from a plurality of said at least one sensors.

7. The system as in any one of the preceding claims, wherein said processor is configured to vary a size of said mark to be printed from a size of said mark that was transmitted to said system.

8. The system as in any one of the preceding claims, wherein said increment is along a y-axis of said substrate to be printed.

9. The system as in any one of claims 1-7, wherein said increment is along an x-axis of said substrate to be printed.

10. A method of varying a width of an incrementing movement of an autonomous printer, comprising:

Altering by a processor, an estimate of a current position on a substrate to be printed of a print head of an autonomous printer from a first current estimated position to a second current estimated position;

Calculating by said processor a width of a fixed number of printing positions using said first current estimated position;

Calculating by said processor a width of said number of printing positions using said second estimated position; and

varying a distance of an incrementing movement of said printer on said substrate from said first width to said second width.

11. The method as in claim 10, wherein said method comprises varying a dimension of a character to be printed in a first of said fixed number of printing positions.

12. The method as in any one of claims 10 and 11, comprising interpolating a number of unvaried increments into a number of printing positions that remain to be printed on a line.

13. The method as in any one of claims 10 - 12, wherein said incrementing movement comprises a movement along an x-axis of said substrate to be printed.

14. A method for correcting a rotational misalignment of a printing by an autonomous printing device comprising:

incrementing a first movement of an autonomous printing device along a y-axis of a substrate to be printed by a first distance;

detecting a rotational misalignment of a printing by said autonomous printing device of a swath; and incrementing a second movement of said autonomous printing device along said y-axis of the substrate to be printed by a second distance.

15. The method as in claim 14, wherein said second distance is less than said first distance, and further comprising, following said second incrementing, aligning a print head of said autonomous printing device over a portion of said swath.

16. The method as in claim 15, comprising, following said second incrementing, printing on at least one printing position of said swath that is offset from a printing on said printing position of said swath prior to said second incrementing.

17. The method as in any one of claims 14 - 16, further comprising:

repeating a printing in at least one printing position on said swath following said second incrementing; and,

offsetting in said repeating of said printing on said at least one printing position an alignment of said repeated printing.

18. The method as in any one of claims 14-17, wherein said swath comprises a first swath printed before said second movement, and comprising offsetting a printing on at least one printing position of second swath relative to said at least one position of said first swath.

19. An autonomous printing carriage comprising at least one indicator, said indicator visible from outside of said autonomous printing carriage, said indicator aligned with a position of a print head of said autonomous printing carriage.

20. An autonomous printing carriage as in claim 19, wherein said at least one indicator comprises a first indicator, and comprising a second indicator, said first indicator on a first side of said autonomous printing carriage, and said second indicator on a second side of said autonomous printing carriage, wherein an imaginary line intersecting said first and said second indicators indicates said position of said print head.

21. An autonomous printing carriage as in any one of claims 19 and 20, wherein said at least one indicator comprises a light, said light to illuminate a position on a substrate to be printed, said position aligned with said printing head.

22. An autonomous printing carriage as in any one of claims 19 - 21, wherein said at least one indicator comprises a first indicator, and comprising a second indicator, said first indicator on a first side of said autonomous printing carriage, and said second indicator on a second side of said autonomous printing carriage, wherein an imaginary line connecting said first indicator and said second indicator align a lateral position of said print head.

23. An autonomous printing carriage as in claim 19, wherein said at least one indicator comprises a first indicator, and comprising a second indicator, said first indicator on a first side of said autonomous printing carriage, and said second indicator on a second side of said autonomous printing carriage, wherein in imaginary line connecting said first indicator and said second indicator align a vertical position of said starting point of said printing.

24. A method of selecting a placement on a substrate of an autonomous printing carriage, comprising, aligning an indicator of said carriage, said indicator visible on an outside of said autonomous printing carriage, with a position on said substrate to be printed at a start of a printing task.

25. The method as in claim 24, wherein said indicator comprises a first indicator, and comprising aligning said position on said substrate with an imaginary intersecting line of said first indicator and a second visible indicator on said autonomous printing carriage.

26. The method as in claim 24, wherein said indicator comprises a first indicator, and comprising aligning said position on said substrate with an imaginary connecting line from said first indicator to a second visible indicator on said autonomous printing carriage.

27. The method as in claim 24, wherein said aligning said indicator comprises aligning a light emitted from said indicator.

28. An autonomous printing device comprising an aperture on a ventral side of the device through which a print cartridge is insertable into said autonomous printing device.

29. The printing device as in claim 28, wherein said aperture is configured to accommodate said print cartridge held by a print head carrier.

30. The printing device as in any one of claims 28 and 29, comprising a print cartridge carrier configured to be held in a cavity located dorsally to said aperture, said carrier configured to hold said print cartridge upon its insertion through said aperture.

31. The printing device as in any one of claims 28 and 29, comprising a cavity dorsal to said aperture, said cavity configured to contain said print cartridge upon said insertion, an underside of said cavity including a cover configured to cover said cartridge upon its insertion into said device.

32. The printing device as in any one of claims 28 and 29, comprising an openable cover of said aperture.

33. The device as in any one of claims 28 - 32, wherein print nozzles of said print cartridge protrude through said aperture into which said cartridge is insertable.

34. A method of inserting a print cartridge into an autonomous printing device, said method comprising inserting said print cartridge through a ventral aperture in said autonomous printing device.

35. The method as in claim 34 comprising inserting said print cartridge into a print cartridge carrier, said print cartridge carrier held in a cavity of said autonomous device, said cavity dorsal to said aperture.

36. The method as in any one of claims 34 and 35, comprising opening a cover of said aperture, said opening to expose a print nozzle of said print cartridge.

37. The method as in claim 36, comprising closing said cover, said cover configured to retract said print nozzle upon said closure.

38. The method as in claim 34, comprising: compressing a spring in a cavity of said autonomous printing device, said compressing upon said insertion of said print cartridge; and decompressing said spring upon an extraction of said print cartridge from said cavity.

39. The method as in claim 33, comprising opening a cover of said aperture upon an initiation of a printing by said autonomous printing device; and closing said cover upon a completion of said printing.