EP1238814B1 - Imprimante à jet d'encre équipée pour aligner ses têtes d'impression - Google Patents

Imprimante à jet d'encre équipée pour aligner ses têtes d'impression Download PDF

Info

Publication number
EP1238814B1
EP1238814B1 EP20020100131 EP02100131A EP1238814B1 EP 1238814 B1 EP1238814 B1 EP 1238814B1 EP 20020100131 EP20020100131 EP 20020100131 EP 02100131 A EP02100131 A EP 02100131A EP 1238814 B1 EP1238814 B1 EP 1238814B1
Authority
EP
European Patent Office
Prior art keywords
frame
printhead
nozzles
image receiving
receiving substrate
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.)
Expired - Lifetime
Application number
EP20020100131
Other languages
German (de)
English (en)
Other versions
EP1238814A1 (fr
Inventor
Hilbrand Vanden Wyngaert
Bart Verhoest
Dirk De Ruijter
Bart Verlinden
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.)
Agfa Gevaert NV
Agfa Gevaert AG
Original Assignee
Agfa Gevaert NV
Agfa Gevaert AG
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
Priority claimed from EP01000045A external-priority patent/EP1238813A1/fr
Application filed by Agfa Gevaert NV, Agfa Gevaert AG filed Critical Agfa Gevaert NV
Priority to EP20020100131 priority Critical patent/EP1238814B1/fr
Publication of EP1238814A1 publication Critical patent/EP1238814A1/fr
Application granted granted Critical
Publication of EP1238814B1 publication Critical patent/EP1238814B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

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
    • B41J25/00—Actions or mechanisms not otherwise provided for
    • B41J25/001—Mechanisms for bodily moving print heads or carriages parallel to the paper surface
    • B41J25/005—Mechanisms for bodily moving print heads or carriages parallel to the paper surface for serial printing movements superimposed to character- or line-spacing movements
    • 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
    • B41J2/135—Nozzles
    • B41J2/145—Arrangement thereof
    • B41J2/155—Arrangement thereof for line printing
    • 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
    • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/485—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by the process of building-up characters or image elements applicable to two or more kinds of printing or marking processes
    • B41J2/505—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by the process of building-up characters or image elements applicable to two or more kinds of printing or marking processes from an assembly of identical printing elements
    • B41J2/515—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by the process of building-up characters or image elements applicable to two or more kinds of printing or marking processes from an assembly of identical printing elements line printer type
    • 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

Definitions

  • This invention relates to an ink-jet printer with at least page-wide printhead structures and especially to a system for aligning these printhead structures with respect to each other and the image receiving substrate.
  • Ink-jet printing has become a widely used printing technique especially in the digitally controlled electronic printing business.
  • ink-jet printing mechanisms have been invented. These can be categorised as either continuous inkjet (CIJ) or drop on demand (DOD) ink-jet.
  • CIJ continuous inkjet
  • DOD drop on demand
  • colour printers have been designed, wherein from multiple printhead structures different colours are printed. Properly controlling the arrangement of various droplets of ink of different colours will result in a wide spectrum of perceivable colours. The clarity and quality of the resultant image is affected by the accuracy of the placement of the ink droplets on the medium.
  • Printers which use multiple printhead structures to co-operatively form a single image usually require mechanical or electronic adjustment so that ink droplets printed by one printhead align at precise locations on the receiving medium relative to those printed by another printhead in the printer.
  • Several methods to achieve the accurate alignment of the rows of droplets ejected by the different printhead structures have been proposed,
  • the ink-jet printer is equipped with a source of illumination that is passed across a test pattern having features indicative of printhead structure alignment and discernible under the illumination.
  • the source of illumination is connected to circuitry that determines the variation in light intensity of the test pattern.
  • a value indicative of the misalignment is calculated and used to correct the timing of firing signals between the sequentially fired banks of nozzles of a printbar.
  • US-A-5 751 305 it is disclosed to place a referencing mechanism on the printer and a detector on the printhead in order to dynamically align one or more printheads in a printer.
  • the printhead structure is moved at a known speed past two spaced apart reference indicia of the referencing mechanism.
  • the passing of a first of the spaced apart reference indicia is detected and the passing of a second of the spaced apart reference indicia is detected.
  • the time between the detection of the first reference indicia passage and the detection of the second reference indicia passage is measured and a delay time, related to the measured period of time, is created. Energization of an ink drop ejection is delayed for the duration of the delay time.
  • the pagewidth printhead structure would include a reference plate, a linear array of ink jet sub-units affixed to the reference plate, and a plurality of alignment sub-units affixed on opposite ends of the planar surface of said reference plate.
  • the ink jet printer would also include alignment or reference points for engaging the alignment sub-units and thereby aligning the pagewidth printhead structure with respect to the frame. However once the printhead structure is aligned in the frame no further fine tuning of the alignment is foreseen.
  • a bi-directional print position alignment system for automatically aligning bi-directional printing position of a printhead structure in a serial printer as a function of high sensor accuracy and clock frequency of a CPU controlling the sensor.
  • the alignment system includes a sensing section for sensing a position of a printhead structure for vertical alignment, a misalignment detecting section for detecting mechanical misalignment of the printhead structure, and a printing section for correcting said mechanical misalignment of the printhead structure and printing information on a printable medium after said mechanical misalignment of the printhead structure is corrected.
  • test patterns are disclosed that are useful for printhead structure alignment.
  • the test patterns are optically sensed and the sensed patterns are used to electronically adjust the alignment, either by adjusting the firing time of the nozzles, or by shifting the pattern of ink-jet nozzles from which the ink is ejected.
  • the present invention is a method for aligning printhead structures in an ink-jet printer as claimed in independent claim 6, and a system in which the method is implemented as claimed in independent claim 1. Preferred embodiments of the invention are set out in the dependent claims.
  • any ink jet printer comprising more than one printhead structure desirable to have means and ways of aligning the printhead structures with respect to each other and to the edge of the image receiving member.
  • classical (e.g. offset) printing by digital printing techniques e.g. electrostatic printing or ink jet printing
  • SOHO small office/home office
  • digital printing techniques e.g. electrostatic printing or ink jet printing
  • each of the printhead structures is coupled to at least one mechanical means for aligning the nozzles of said at least two different printhead structures in at least one of the x- and y-direction.
  • a mechanical alignment of the nozzles in the print direction forgoes the adaptation of the firing time of each individual nozzle to the degree of parallelism between the nozzles of two different print heads and/or to the difference in distance between the nozzle arrays.
  • This mechanical alignment has the advantage that the computing power during printing can be lower. This advantage is most pronounced in a printer that comprises multiple printhead structures, e.g., six - four for the YMCK printing and two for further supporting colours - because in such printer the alignment of the nozzles of the six different printhead structures based on adjustment of the firing time demands very much of the computing power and on the electronics of the printhead. Even if the computing power can be provided, it can be impossible to adjust the firing time of each individual nozzle due to limitations in the electronics of the printhead.
  • a mechanical alignment in the x-direction i.e. the possibility of mechanically displacing the nozzles of the different printhead structures in a direction perpendicular to the print direction has the advantage that mechanical means can be introduced so that the displacement of the nozzles can be effected over a fraction of the nozzle pitch, whereas in prior art embodiment for alignment in the x-direction, a "displacement" was always disclosed to go over an integer number of nozzle pitches.
  • each of the printhead structures is coupled to at least one mechanical means for aligning the nozzles of said at least two different printhead structures in both said y- and x-direction.
  • FIG 1 a first embodiment of an ink jet printer according to this invention is schematically shown.
  • An image receiving substrate (100) with an x-edge (100x) and a y-edge (100y) is guided by a guiding means (123) past printhead structure (104) with an array of nozzles (105).
  • the guiding means and the image receiving substrate are shown as being transparent for sake of clarity.
  • the printhead structure (104) is mounted in an y-frame (103) so that the array of nozzles defines an x-direction, perpendicular to the print direction, that defines an y-direction.
  • the y-frame (103) is mounted in an x-frame (102) by attachments (110) so that it can be moved in a direction parallel to the print direction (arrows A) and/or that it can get an angular movement (arrows B) with respect to the x-frame. Therefore on both ends of the end of the y-frame a linear actuator (106) coupled to a stepping motor (106') is mounted in contact with the y-frame and the x-frame. Opposite to each of the actuators (106) a play spring (109) is present to avoid play of the printhead structure in the y-direction, once it is aligned.
  • the x-frame (102) is mounted in a master frame (101) by fastening means (111), that allow for sliding movement in the x-direction.
  • a linear actuator (107) coupled to a stepping motor (107') is mounted in contact with the x-frame (102) and the master frame (101).
  • a play spring (108) is mounted opposite to the linear actuator (107) to avoid play of the printhead structure in the x-direction, once it is aligned.
  • FIG 2 a second embodiment of an ink jet printer according to this invention is very schematically shown.
  • the schematically shown ink jet printer comprises only one printhead structure, it is however clear that it is possible to include any desired number of printhead structures in a printer according to this invention.
  • An image receiving substrate (100) with an x-edge (100x) and a y-edge (100y) is guided by a guiding means (123) past printhead structure (104) with an array of nozzles (105).
  • the guiding means and the image receiving substrate are shown as being transparent for sake of clarity.
  • the printhead structure (104) is mounted in an y-frame (103) so that the array of nozzles defines an x-direction, perpendicular to the print direction, that defines an y direction.
  • the y-frame (103) is mounted in an x-frame (102) so that it can rotate around an axis (110) located at one end of the printhead structure (104).
  • a linear actuator (106) coupled to a stepping motor (106') is mounted in contact with the y-frame and the x-frame. Actuation of the actuator 106 causes the y-frame to rotate around axis 110 and thus to move in the direction of arrow B.
  • a play spring (109) is present to avoid play of the printhead structure in the y-direction, once it is aligned.
  • the x-frame (102) is mounted in a master frame (101) by fastening means (111), that allow for a sliding movement in the x-direction.
  • a linear actuator (107) coupled to a stepping motor (107') is mounted in contact with the x-frame (102) and the master frame (101).
  • a play spring (108) is mounted opposite to the linear actuator (107) to avoid play of the printhead structure in the x-direction, once it is aligned.
  • the mechanical alignment of the nozzles in the print direction is only an alignment wherein the parallelism of different printhead structures with respect to each other and/or with respect to the x-edge (100x) of the image receiving substrate is changed.
  • the possibility of y-alignment in this second embodiment forgoes the need for adapting the firing time of each individual nozzle to the degree of parallelism between the nozzles of two different printhead structures.
  • An ink jet printer can beneficially further include spacing means for keeping the distance between the printhead structures and the image receiving substrate constant (i.e. for keeping the distance in the z-direction constant).
  • these spacing means can include movable parts coupled to means for adjusting the distance in the z-direction. In that case it is possible to adjust the distance in the z-direction according to the thickness of the image receiving substrate, so that a printer can be built wherein image receiving substrates showing a large variety of thickness can be used and the printer can be adjusted to the thickness of the substrate used, so as to have an optimal "throw distance" (i.e. the distance between the nozzle array and the image receiving substrate) for every substrate thickness.
  • FIG. 3 A possible placement of the spacing means for keeping the distance between the printhead structures and the image receiving substrate constant (i.e. for keeping the distance in the z-direction constant) is schematically shown in figure 3.
  • This figure is a view of the printer in figure 2 along arrow C.
  • the y-frame (102) is shown together with the printhead structure (104) with nozzles (105) coupled to it.
  • the axis 110 around which the y-frame can rotate upon actuation of actuator (106) by a stepping motor (106') is also shown.
  • the y-frame carries on the side of it facing the guiding means (123) for guiding an image receiving substrate past the printhead structure (104) a number of spacers (e.g.
  • the movable part (113) of the spacing means is in contact with the guiding means (123) and keeps thus the distance, DIS, between y-frame and guiding means constant.
  • the distance, DIS can be changed so as to keep an optimum "throw distance" when the thickness of the image receiving substrate is changed.
  • the spacing means (112) for keeping the distance between the printhead structures and the image receiving substrate constant are shown as being present on the side of the y-frame (102) facing the guiding means (123) and as including a movable part (113). It is clear that the purpose of the spacing means for keeping the distance between the printhead structures and the image receiving substrate constant can be achieved in other configurations. E.g., it is possible to have spacing means, not including a movable part, between the master frame (101) and the guiding means (123)for the image receiving substrate. Then the y-frame is coupled to the x-frame in such a way that it not only can be moved for adjusting the y-position of it, but also for adjusting the z-position. When the y-frame is coupled to the x-frame in this way, mechanical means, e.g., linear actuators, for moving the y-frame in the z-direction can be incorporated between the x- and y-frame.
  • mechanical means e.g., linear actuators
  • a printer of this invention with spacing means, not including a movable part, between the master frame (101) and the guiding means (123)for the image receiving substrate. Then the x-frame is coupled to the master frame in such a way that it not only can be moved for adjusting the x-position of it, but also for adjusting the z-position.
  • mechanical means e.g., linear actuators , for moving the x-frame in the z-direction can be incorporated between the master frame and the x-frame.
  • the mechanical means for adjusting the printhead structures in the y-, x- and, if so desired, in the z-direction are linear actuators.
  • the linear actuators are preferably adjusted so as to be able to displace the printhead structures over a distance between about 1 pm and about 10 mm.
  • the linear actuators are preferably construed so as to allow for an alignment that is adapted to the nozzle pitch of the nozzle arrays in the printhead.
  • the linear actuators are preferably designed so as to allow an alignment - i.e. a displacement of the printheads - in steps as small as 1/20th of the nozzle pitch.
  • Linear actuators allowing for a displacement in steps as small as 1/10th of the nozzle pitch can however also be beneficially used when high accuracy of the alignment is desired.
  • linear actuators allowing for a displacement of the printheads in steps between 1 to 100 ⁇ m (both limits included)can beneficially be used.
  • linear actuators allowing for a displacement (alignment) in steps between 2 and 50 ⁇ m are used.
  • a 720 dpi printer has a nozzle pitch of 35 ⁇ m.
  • the actuators can be manually driven, e.g. they can be micrometer screws or can, preferably, be powered by stepping motors. In the latter case the linear actuators are preferably the spindles of the stepping motors.
  • micrometer screws are used for the displacement (alignment) of the printheads
  • micrometer screws allowing for a displacement (alignment) accuracy between 2 and 50 ⁇ m are used.
  • stepping motors for use in an ink jet printer of this invention have preferably a combination of motor step and spindel pitch so that a linear displacement in steps between 1 ⁇ m and 100 ⁇ m (both limits included),more preferably in steps between 2 ⁇ m and 50 ⁇ m (both limits included) is possible.
  • the displacement can proceed in steps between 1 ⁇ m and 100 ⁇ m (both limits included), more preferably in steps between 2 ⁇ m and 50 ⁇ m (both limits included).
  • Possible misalignment of the printheads can be detected offline.
  • a template of a test image can be provided with the printer.
  • the operator of the printer can then compare an actual print of the test image on the printer with the target output as shown in a template of the test image. If the operator detects misalignment - i.e. differences between the print of the test image and the template of it - he can either manually adjusts the micrometer screws to align the printheads so as to have an actual output corresponding to the target output or he can activate the stepping motors to align the printheads.
  • an ink jet printer according to this invention is preferably further equipped with means for sensing the relative position of the printhead structures with respect to each other.
  • an ink jet printer according to this invention is equipped with means for sensing the relative position of the printhead structures not only with respect to each other, but also with respect to one or more edges of the image receiving substrate.
  • the means for sensing the relative position of the printhead structures and/or the edge(s) of the image receiving member can beneficially be optical means, e.g.
  • CCD-cameras that are placed in the printer such as to read a printed test image and/or the edges of the images receiving substrate. In this way possible misalignments between the nozzles of the different printhead structures and/or the edge of the paper are detected.
  • the means for sensing the position of the printhead structures can be coupled to a computer so as to compare the actual data of the test image with the target data and to display the degree of misalignment on the computer screen. An operator of the printer then reads this information and actuates the linear actuators for aligning the printhead structures.
  • the computer wherein the target positions and tolerances thereon in the y-, x- and, if so desired, the z-direction, are stored and compared with the actual values sensed by the sensing means, is further coupled to stepping motors for actuating the linear actuators automatically to a degree depending on the difference between actual positions sensed by the means for sensing the position of the printhead structures and the target positions. In this way the alignment can proceed automatically.
  • the invention further encompasses a method for aligning printhead structures in an ink jet printer comprising the steps of :
  • a further step of sensing the actual data of the test image with optical sensors is inserted.
  • a y-edge and/or an x-edge of said image receiving substrate is sensed.
  • a step of sensing the edge of the image receiving substrate that is substantially orthogonal to the print direction herein after called "x-edge”
  • a step of sensing one of the edges of the image receiving substrate that is substantially parallel to the print direction herein after called "y-edge”
  • said actual data of the test image sensed with optical sensors are sent to a computer memory and said step of comparing the actual data with target data is executed in said computer memory.
  • said computer wherein the actual data are compared with target data is also coupled to the mechanical actuators and when in said computer a difference between the actual data and the target data of the test image is found, the computer automatically executes the step of actuating the mechanical actuators.
  • a printer according to this invention incorporating optical sensors for sensing a test image together with a first stage of a possible implementation of a method for aligning the printhead structures is shown in figure 4.
  • two printhead structures (104 and 104a) are schematically shown.
  • the same numericals as in figure 1 to 3 are used for designating the same parts of the printhead structure, the numericals of the second printhead structure have been provided with the letter "a”.
  • the printer, shown in figure 1, is further schematised in this figure 4.
  • the master frame and the x- and y-frames and the spacers are omitted for clarity and the figure 4 shows two printhead structures (104, 104a) each with an array of nozzles (105, 105a), the array of nozzles (105) in the printhead (104) has a number of nozzles n 1 to n x , the array of nozzles (105a) in the printhead (104a) has a number of nozzles n 1 a to n x a.
  • Both printhead structures are coupled to linear actuators (106, 106a, 107, 107a) for aligning them in the y- and x-direction respectively.
  • Play springs (108, 108a, 109, 109a) are placed in the printer so as to press the printhead structures firmly against the linear actuators.
  • the printhead structures can rotate around an axis (110, 110a) and are supported in the x-direction by fastening means (111, 111a) leaving the possibility for sliding the printhead structures in the x-direction.
  • the printhead structures are shown as deviating from the target position, in the x-direction the deviation is half the nozzle pitch (NP, NPa) and in the y-direction the non-parallelism of the printhead structures is exaggerated for sake of clarity.
  • An image receiving substrate (100) with y- edge (100y) and an x-edge (100x) passes the printhead structures in the y-direction.
  • a sensor (114) senses the arrival of the image receiving substrate in the printing zone and signals the arrival of the image receiving substrate so as to start the printing.
  • Two lines (120a, 120'a) substantially parallel to the y-edge of the image receiving substrate are printed using the first nozzle (n 1 a) and the last nozzle (n x a) of printhead 104a. Then the image receiving substrate passes image sensors (115 and 116) so that the lines 120a and 120'a, printed by the first printhead structure (104a) are sensed and a distance, w, between both lines is detected.
  • this distance, w equals (n x a - 1)NPa, the target value for distance, w tar .
  • the actual distance w is then compared with the target distance , w tar .
  • the mechanical actuator 106a is actuated so as to displace the printhead 104a perpendicular to the y-direction.
  • printhead 104a is placed perpendicular to the y-direction
  • both printhead structures (104, 104a) print a line (121, 121a) substantially parallel to the x-edge of the image receiving substrate and a line (120, 120a) substantially parallel to the y-edge of the image receiving substrate.
  • the image receiving substrate passes again image sensors (115 and 116) so that the line 121a, printed by the first printhead structure (104a) is sensed first and the line 121 printed by the second printhead structure (104) is sensed secondly.
  • the lines 120 and 120a are sensed by the sensor 118, and it is determined if both lines are in line, if a difference, d is found, then the actuators, 107 and 107a are actuated for bringing both lines, 120 and 120a in line.
  • the alignment proceeds first to bring the printhead structures parallel to each other (y-alignment) and that then the printhead structures are aligned in the x-direction.
  • y-alignment the method has been explained with only 2 printhead structures, it is clear that the method can be used for aligning more than two printhead structures, e.g., when the first two printhead structures are aligned, then the third is aligned with reference to the already aligned printhead structures and so on until all printhead structures are aligned with respect to each other.
  • figure 6 a further implementation of the method of this invention is shown, wherein the printhead structures are aligned with respect to the edges of the image receiving substrate.
  • the figure is basically the same as figures 4 and 5, both printhead structures (104, 104a) print a line (121, 121a) substantially parallel to the x-edge of the image receiving substrate and a line (120, 120a) substantially parallel to the y-edge of the image receiving substrate.
  • the image receiving substrate passes image sensors (115 and 116) so that de x-edge of the image receiving substrate is sensed (see dashed line 100'x).
  • the sensors 115 and 116 sense the line 121a, printed by the first printhead structure (104a).
  • the lines 120 and 120a are sensed by the sensor 118, and it is determined if both lines are at the same distance from the y-edge of the image receiving substrate. If d' ⁇ d, then the actuators, 107 and 107a are actuated for bringing both lines, 120 and 120a in line. It is preferred that the alignment proceeds first to bring the printhead structures parallel to each other (y-alignment) and that then the printhead structures are aligned in the x-direction.
  • the method has been explained with only 2 printhead structures, it is clear that the method can be used for aligning more than two printhead structures, e.g., when the first two printhead structures are aligned with respect of the edges of the image receiving substrate, then the third is aligned with reference to the already aligned printhead structures and so on until all printhead structures are aligned with respect to each other and with respect to the edges of the image receiving substrate.
  • the method according to this invention has been explained with the use of 3 sensors (figures 4 and 5), 4 sensors (figure 6), the number of optical sensors is basically determined by the quality of alignment of the printhead structures that is desired.
  • the method of this invention can be executed with only two sensors, e.g., sensors 115 and 116.
  • the sensors as shown in figures 4, 5 and 6 have a certain range so as to be able to sense lines that are a number of nozzle pitches apart and have a resolution as to be able to sense a misalignment of at least one tenth of the nozzle pitch NP. It is however possible to execute a method according to this invention using smaller sensors that , e.g., are designed to sense over the width of a nozzle pitch when these are placed in close proximity.

Landscapes

  • Engineering & Computer Science (AREA)
  • Quality & Reliability (AREA)
  • Ink Jet (AREA)

Claims (8)

  1. Imprimante à jet d'encre pour imprimer sur un substrat de réception d'une image (100), l'imprimante à jet d'encre comprenant :
    un moyen de guidage (123) pour guider ledit substrat de réception d'une image (100) dans une direction selon y ;
    un premier carter selon x (102), monté à translation dans une première direction selon x ;
    un premier carter selon y (103), monté dans ledit premier carter selon x (102) et rotatif autour d'un premier axe (110) perpendiculaire à ladite première direction selon x et perpendiculaire à ladite direction selon y ;
    une première structure de tête d'impression (104), montée dans ledit premier carter selon y (103) et dotée d'un premier groupement de buses (105) définissant ladite première direction selon x ;
    un deuxième carter selon x, monté à translation dans une deuxième direction selon x ;
    un deuxième carter selon y, monté dans ledit deuxième carter selon x et rotatif autour d'un deuxième axe (110a) perpendiculaire à ladite deuxième direction selon x et perpendiculaire à ladite direction selon y ;
    une deuxième structure de tête d'impression (104a), montée dans ledit carter selon y et dotée d'un deuxième groupement de buses (105a) définissant ladite deuxième direction selon ;
    un moyen de réglage d'un temps d'excitation d'au moins une parmi ledit premier groupement de buses (105) et ledit deuxième groupement de buses (105a).
  2. Imprimante selon la revendication 1, comprenant en outre :
    un premier moyen d'actionnement (106) pour entraíner en rotation ledit premier carter selon y (103) autour dudit premier axe (110) ;
    un deuxième moyen d'actionnement (106a) pour entraíner en rotation ledit deuxième carter selon y autour dudit deuxième axe (110a) ;
    un troisième moyen d'actionnement (107) pour entraíner en translation ledit premier carter selon x (102) dans ladite première direction selon x ;
    un quatrième moyen d'actionnement (107) pour entraíner en translation ledit deuxième carter selon x dans ladite deuxième direction selon x.
  3. Imprimante à jet d'encre selon la revendication 2, dans laquelle lesdits troisième (107) et quatrième (107) moyens d'actionnement permettent un déplacement par pas compris entre 2 µm et 50 µm, ces deux limites incluses.
  4. Imprimante à jet d'encre selon l'une quelconque des revendications précédentes, comprenant en outre :
    des moyens de détection (114 - 119) d'un premier motif de contrôle (120a, 120'a, 121, 121a) imprimé sur ledit substrat de réception d'une image par lesdits premier (105) et deuxième (105a) groupements de buses.
  5. Imprimante à jet d'encre selon la revendication 4, dans lequel lesdits moyens de détection (114 - 119) sont couplés à un ordinateur pour détecter une différence entre une position détectée et une position cible, stockée dans une mémoire dudit ordinateur, de ladite première structure de tête d'impression (104) par rapport à ladite deuxième structure de tête d'impression (104a).
  6. Procédé d'alignement d'une première (104) et d'une deuxième (104a) structure de tête d'impression dans une imprimante à jet d'encre, ladite première structure de tête d'imprimante (104) comprenant un premier groupement de buses (105) et ladite structure de tête d'impression (104a) comprenant un deuxième groupement de buses (105a), le procédé comprenant les étapes de :
    guidage d'un substrat de réception d'une image (100) dans une direction selon y ;
    impression d'un motif de contrôle (120a, 120'a, 121, 121a) par lesdits premier et deuxième groupements de buses (105, 105a) sur ledit substrat de récention d'une image (100) :
    détection dudit motif de contrôle (120a, 120'a, 121, 121a), pour obtenir ainsi des données d'alignement effectif desdites première (104) et deuxième (104a) structures de tête d'impression ;
    comparaison desdites données d'alignement effectif à des données d'alignement cible ;
    en fonction de ladite comparaison, exécution des étapes suivantes :
    entraínement en translation d'un premier carter selon x (102) dans une première direction selon x définie par ledit premier groupement de buses (105) ;
    entraínement en rotation d'un premier carter selon y (103) autour d'un premier axe (110) perpendiculaire à ladite première direction selon x et perpendiculaire à ladite direction en y, ladite première structure de tête d'impression (104) étant montée dans ledit premier carter selon y (103), et ledit premier carter selon y (103) étant monté dans ledit premier carter selon x (102) ;
    entraínement en translation d'un deuxième carter selon x dans une deuxième direction selon x définie par ledit deuxième groupement de buses (105a) ;
    entraínement en rotation d'un deuxième carter selon y autour d'un deuxième axe (110a) perpendiculaire à ladite deuxième direction selon x et perpendiculaire à ladite direction selon y, ladite deuxième structure de tête d'impression (104a) étant montée dans ledit deuxième carter selon y, et ledit deuxième carter selon y étant monté dans ledit deuxième carter selon x ;
    réglage d'un temps d'excitation d'au moins une parmi ledit premier groupement de buses (105) et ledit deuxième groupement de buses (105a).
  7. Procédé selon la revendication 6, comprenant en outre l'étape de :
    détection d'un bord (100x, 100y) dudit substrat de réception d'une image (100).
  8. Procédé selon la revendication 7, comprenant en outre l'étape de :
    alignement desdites première (104) et deuxième (104a) structures de tête d'impression par rapport audit bord (100x, 100y) dudit substrat de réception d'une image (100).
EP20020100131 2001-03-08 2002-02-13 Imprimante à jet d'encre équipée pour aligner ses têtes d'impression Expired - Lifetime EP1238814B1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP20020100131 EP1238814B1 (fr) 2001-03-08 2002-02-13 Imprimante à jet d'encre équipée pour aligner ses têtes d'impression

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
EP01000045 2001-03-08
EP01000045A EP1238813A1 (fr) 2001-03-08 2001-03-08 Imprimante jet d'encre équipée pour aligner les têtes d'impression
EP20020100131 EP1238814B1 (fr) 2001-03-08 2002-02-13 Imprimante à jet d'encre équipée pour aligner ses têtes d'impression

Publications (2)

Publication Number Publication Date
EP1238814A1 EP1238814A1 (fr) 2002-09-11
EP1238814B1 true EP1238814B1 (fr) 2003-12-03

Family

ID=26076404

Family Applications (1)

Application Number Title Priority Date Filing Date
EP20020100131 Expired - Lifetime EP1238814B1 (fr) 2001-03-08 2002-02-13 Imprimante à jet d'encre équipée pour aligner ses têtes d'impression

Country Status (1)

Country Link
EP (1) EP1238814B1 (fr)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7434927B2 (en) 2002-11-26 2008-10-14 Ricoh Company, Ltd. Inkjet recording device
WO2007039444A1 (fr) * 2005-09-20 2007-04-12 Agfa Graphics Nv Procede et appareil pour aligner automatiquement des reseaux d'elements d'impression
EP1764996A1 (fr) * 2005-09-20 2007-03-21 Agfa Graphics N.V. Procédé et appareil pour l'alignement automatique de matrices d'éléments d'impression
GB2448695B (en) * 2007-04-23 2012-07-11 Inca Digital Printers Ltd Large-scale inkjet printer
US8075086B2 (en) * 2009-07-31 2011-12-13 Xerox Corporation Paper skew detection system

Family Cites Families (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US541990A (en) 1895-07-02 Hot-gas valve
US5297017A (en) 1991-10-31 1994-03-22 Hewlett-Packard Company Print cartridge alignment in paper axis
US5241325A (en) * 1991-10-31 1993-08-31 Hewlett-Packard Company Print cartridge cam actuator linkage
US5250956A (en) 1991-10-31 1993-10-05 Hewlett-Packard Company Print cartridge bidirectional alignment in carriage axis
US5276467A (en) 1992-05-04 1994-01-04 Hewlett-Packard Company Alignment system for multiple color pen cartridges
US5428375A (en) * 1992-05-29 1995-06-27 Simon; Robert J. Multiple print head ink jet printer
US5404020A (en) 1993-04-30 1995-04-04 Hewlett-Packard Company Phase plate design for aligning multiple inkjet cartridges by scanning a reference pattern
US5448269A (en) 1993-04-30 1995-09-05 Hewlett-Packard Company Multiple inkjet cartridge alignment for bidirectional printing by scanning a reference pattern
EP0622239B1 (fr) 1993-04-30 1998-08-26 Hewlett-Packard Company Système pour l'alignement de cartouches d'impression par jet d'encre multiples
US5534895A (en) 1994-06-30 1996-07-09 Xerox Corporation Electronic auto-correction of misaligned segmented printbars
US5751305A (en) * 1995-09-29 1998-05-12 Hewlett-Packard Company Method and apparatus for dynamically aligning a printer printhead
US6106094A (en) * 1996-01-30 2000-08-22 Neopt Corporation Printer apparatus and printed matter inspecting apparatus
DE69707204T2 (de) * 1996-06-18 2002-05-16 Scitex Digital Printing, Inc. Modular elektronische Druckerarchitektur
JPH10109458A (ja) * 1996-08-14 1998-04-28 Seiko Epson Corp インクジェット記録装置における記録ヘッドの位置調整機構
JPH11240204A (ja) * 1998-02-25 1999-09-07 Canon Aptex Inc 記録装置
US6213580B1 (en) * 1998-02-25 2001-04-10 Xerox Corporation Apparatus and method for automatically aligning print heads
US6189991B1 (en) * 1998-08-14 2001-02-20 Eastman Kodak Company Compensating for receiver skew and changing resolution in ink jet printer

Also Published As

Publication number Publication date
EP1238814A1 (fr) 2002-09-11

Similar Documents

Publication Publication Date Title
US6554398B2 (en) Ink-jet printer equipped for aligning the printheads
US5835108A (en) Calibration technique for mis-directed inkjet printhead nozzles
EP1764226B1 (fr) Dispostif et méthode d'alignement automatique de rangés d'éléments d'impression
EP0791472B1 (fr) Impression à jet d'encre
EP0571804B1 (fr) Imprimante par jet d'encre multi-têtes
EP0693382B1 (fr) Imprimante avec une tête d'impression mobile
US6568782B1 (en) Calibration system to correct printhead misalignments
EP1238813A1 (fr) Imprimante jet d'encre équipée pour aligner les têtes d'impression
US5451990A (en) Reference pattern for use in aligning multiple inkjet cartridges
EP0622237B1 (fr) Concept de lame de phase pour l'alignement de cartouches à jet d'encre utilisant le balayage d'un motif de référence
JP3483614B2 (ja) インクジェット・カートリッジの整列用装置
EP0540243B1 (fr) Alignement d'une cassette d'impression dans l'axe du papier
JP3319492B2 (ja) インクジェットプリンタにおけるヘッド位置調整機構及びヘッド位置調整方法
EP1764996A1 (fr) Procédé et appareil pour l'alignement automatique de matrices d'éléments d'impression
KR101703534B1 (ko) 프린트 헤드 조정장치
EP1764224A1 (fr) Méthode et appareil pour l'impression numérique en maintenant l'alignement de points imprimés sous de conditions d'impression variées
JP7518678B2 (ja) インクジェット記録装置及びその制御方法
US6382752B1 (en) Adjustable chassis for automated writing instrument carriage
JPH11263029A (ja) ペ―ジ幅インクジェットプリンタ及びその製造方法
EP1238814B1 (fr) Imprimante à jet d'encre équipée pour aligner ses têtes d'impression
WO2007039444A1 (fr) Procede et appareil pour aligner automatiquement des reseaux d'elements d'impression
US7891757B2 (en) Marking element registration
EP1201432A1 (fr) Appareil et méthode pour améliorer la qualité d'impression
CN101037056A (zh) 打印系统及其校正喷墨位置的方法
CN1676333A (zh) 打印系统及其校正喷墨位置的方法

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR

AX Request for extension of the european patent

Free format text: AL;LT;LV;MK;RO;SI

17P Request for examination filed

Effective date: 20030311

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

AKX Designation fees paid

Designated state(s): DE FR GB

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE FR GB

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

REF Corresponds to:

Ref document number: 60200107

Country of ref document: DE

Date of ref document: 20040115

Kind code of ref document: P

ET Fr: translation filed
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

REG Reference to a national code

Ref country code: IE

Ref legal event code: MM4A

26N No opposition filed

Effective date: 20040906

REG Reference to a national code

Ref country code: GB

Ref legal event code: 732E

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20080116

Year of fee payment: 7

Ref country code: GB

Payment date: 20080117

Year of fee payment: 7

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20080128

Year of fee payment: 7

REG Reference to a national code

Ref country code: FR

Ref legal event code: TP

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20090213

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

Effective date: 20091030

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20090901

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20090302

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20090213