Patent ID: 12257829

DESCRIPTION OF EXEMPLARY EMBODIMENTS

FIG.1andFIG.2are diagrams illustrating a schematic configuration of a printing apparatus10.FIG.1is a diagram illustrating the printing apparatus10as viewed from the +X direction.FIG.2is a diagram illustrating the printing apparatus10as viewed from the +Z direction. The printing apparatus10performs printing on a printing medium M fed from a medium roll R1. The printing apparatus10corresponds to an example of a recording apparatus. The printing medium M corresponds to an example of a medium.

Some diagrams includingFIG.1illustrate an XYZ coordinate system. The X axis, the Y axis, and the Z axis are orthogonal to each other. The X axis is parallel to the installation surface of the printing apparatus10. The X axis is an axis that is parallel to the rotation axis of a medium roll R1placed in the printing apparatus10. The rotation axis is a virtual rotation central axis when the medium roll R1rotates. The direction from the far side toward the near side inFIG.1is the +X direction. The direction from the near side toward the far side inFIG.1is the −X direction. The Y axis is parallel to the installation surface of the printing apparatus10. The Y axis is an axis orthogonal to the rotation axis. The direction from right to left of the printing apparatus10illustrated inFIG.1is the +Y direction. The direction from left to right of the printing apparatus10illustrated inFIG.1is the −Y direction. The Z axis is an axis perpendicular to the installation surface of the printing apparatus10. The upward direction from the installation surface is the +Z direction. The direction toward the installation surface from above is the −Z direction.

FIG.1andFIG.2illustrate units disposed along the printing medium M. The printing apparatus10illustrated inFIG.1andFIG.2includes a feed shaft11, a feed roller pair13, a reading sensor15, a printing mechanism16, a conveyance roller pair25, and a winding shaft27.

The feed shaft11supports the medium roll R1composed of the printing medium M wound in a roll form. The feed shaft11is supported in a rotatable manner. The feed shaft11may be connected to a rotation driving mechanism not illustrated in the drawing. The rotation driving mechanism rotates the feed shaft11. The rotated feed shaft11feeds the printing medium M wound around the medium roll R1.

The feed roller pair13feeds the printing medium M toward the printing mechanism16. The direction in which the printing medium M is conveyed at the position facing the printing mechanism16is hereinafter referred to as conveyance direction TD. The feed roller pair13sandwiches the printing medium M. The feed roller pair13includes a first feed roller13A and a second feed roller13B. The first feed roller13A is disposed at a position on the +Z direction side of the second feed roller13B. The first feed roller13A makes contact with the +Z direction side surface of the printing medium M. The second feed roller13B makes contact with the −Z direction side surface of the printing medium M. The first feed roller13A and the second feed roller13B sandwich the printing medium M. One of the first feed roller13A and the second feed roller13B is connected to a driving mechanism not illustrated in the drawing. One of the first feed roller13A and the second feed roller13B is rotated by the driving force of the driving mechanism. The other of the first feed roller13A and the second feed roller13B is rotated to follow. With the driving force of the driving mechanism, the feed roller pair13feeds the printing medium M toward the printing mechanism16. The feed roller pair13conveys the printing medium M in the direction opposite to the conveyance direction TD.

The reading sensor15reads the surface of the printing medium M. The reading sensor15is composed of an image sensor such as a charge coupled device (CCD). The reading sensor15illustrated inFIG.1reads the entire width parallel to the X axis of the printing medium M. In the printing apparatus10illustrated inFIG.1andFIG.2, the reading sensor15reads the printing medium M located between the feed roller pair13and the printing mechanism16. The printing apparatus10illustrated inFIG.1andFIG.2conveys the printing medium M in the direction opposite to the conveyance direction TD. The reading sensor15reads the printing medium M conveyed in the direction opposite to the conveyance direction TD. The reading sensor15reads an image printed by the printing mechanism16on the printing medium M. The position of the reading sensor15is not limited to the position between the feed roller pair13and the printing mechanism16. The reading sensor15may be disposed at a position between the printing mechanism16and the conveyance roller pair25on the conveyance path of the printing medium M. The reading sensor15corresponds to an example of a detection unit.

The printing mechanism16prints images on the printing medium M. The printing mechanism16is of an ink-jet type. The printing mechanism16forms images by ejecting ink to the printing medium M. The printing mechanism16includes a carriage17and a printing head18as illustrated inFIG.1. The printing head18includes a plurality of ink nozzles20. The printing mechanism16is supported by a carriage support shaft19illustrated inFIG.2. The printing mechanism16illustrated inFIG.1andFIG.2moves the carriage17, but this is not limitative. The printing mechanism16may be of a line head type that fixes the printing head18with respect to the printing medium M at the time of printing. The printing mechanism16corresponds to an example of a liquid ejection unit. The ink corresponds to an example of liquid.

The carriage17supports the printing head18. The carriage17moves in a movement direction MD along the carriage support shaft19illustrated inFIG.2. When the carriage17moves, the printing mechanism16moves with respect to the printing medium M. The carriage support shaft19illustrated inFIG.2is parallel to or approximately parallel to the X axis. The carriage17moves in the +X direction and the −X direction with respect to the printing medium M. When the carriage17moves, the printing mechanism16causes the ink nozzle20to perform scanning with respect to the printing medium M. As illustrated inFIG.2, the +X direction is the movement direction MD, and corresponds to an example of a first direction. The movement direction MD may be the −X direction. The carriage17is moved by the driving force of the carriage driving mechanism not illustrated in the drawing. The carriage17corresponds to an example of an ejection unit driving mechanism. In the printing apparatus10illustrated inFIG.1andFIG.2, the printing mechanism16moves with respect to the printing medium M, but this is not limitative. The printing medium M may move in the +X direction and the −X direction with respect to the printing mechanism16. The printing mechanism16moves relative to the printing medium M.

The printing head18is supported by the carriage17. The printing head18includes the plurality of ink nozzles20at a surface that faces the printing medium M. The ink nozzle20can eject the ink to the printing medium M. The ink nozzle20corresponds to an example of a nozzle. The configuration of the ink nozzle20will be described later. Ink of a plurality of colors is supplied to the printing head18from an ink tank or an ink cartridge not illustrated in the drawing.

The carriage support shaft19supports the carriage17in a movable manner. As illustrated inFIG.2, the carriage support shaft19is supported by a first side plate101and a second side plate103. The first side plate101is disposed at a position on the −X direction side of the printing medium M that is being conveyed. The second side plate103is disposed at a position on the +X direction side of the printing medium M that is being conveyed. The carriage support shaft19is supported along the axis intersecting the Y axis. The carriage support shaft19illustrated inFIG.2is supported in parallel to or approximately parallel to the X axis. The first side plate101and the second side plate103may support the feed roller pair13, the reading sensor15, and the conveyance roller pair25.

The conveyance roller pair25conveys the printing medium M printed by the printing mechanism16. The conveyance roller pair25sandwiches the printing medium M. The conveyance roller pair25includes a first conveyance roller25A and a second conveyance roller25B. The first conveyance roller25A is disposed at a position on the +Z direction side of the second conveyance roller25B. The first conveyance roller25A makes contact with the +Z direction side surface of the printing medium M. The second conveyance roller25B makes contact with the −Z direction side surface of the printing medium M. The first conveyance roller25A and the second conveyance roller25B sandwich the printing medium M. One of the first conveyance roller25A and the second conveyance roller25B may be connected to a driving mechanism not illustrated in the drawing. One of the first conveyance roller25A and the second conveyance roller25B is rotated by the driving force of the driving mechanism when connected to the driving mechanism. The other of the first conveyance roller25A and the second conveyance roller25B is rotated to follow. The conveyance roller pair25guides the printing medium M to a winding roll R2. The conveyance roller pair25may convey the printing medium M in the direction opposite to the conveyance direction TD.

The winding shaft27winds, around the winding roll R2, the printing medium M printed by the printing mechanism16. The winding shaft27supports the winding roll R2. The winding shaft27is supported in a rotatable manner. The winding shaft27may be connected to a rotation driving mechanism not illustrated in the drawing. The rotation driving mechanism rotates the winding shaft27. The rotated winding shaft27winds the printing medium M around the winding roll R2. The winding shaft27may wind the printing medium M through a roll core not illustrated in the drawing.

The printing apparatus10illustrated inFIG.1andFIG.2uses the printing medium M wound around the medium roll R1, but this is not limitative. The printing apparatus10may use a cut sheet cut into a predetermined size. In the case where the printing apparatus10uses the cut sheet, the feed shaft11and the winding shaft27are changed to a sheet feeding cassette and a paper tray, respectively.

FIG.3illustrates a relationship between the printing medium M and the printing head18. InFIG.3, the carriage17and the carriage support shaft19are omitted. The printing head18illustrated inFIG.3prints an image on the printing medium M by moving in the movement direction MD. The movement direction MD corresponds to an example of a first direction. The movement direction MD illustrated inFIG.3corresponds to the +X direction. The plurality of ink nozzles20are disposed in the surface of the printing head18that faces the printing medium M. The plurality of ink nozzles20form a plurality of nozzle rows. The ink nozzles20illustrated inFIG.3form a cyan ink nozzle row20C, a light cyan ink nozzle row20LC, a magenta ink nozzle row20M, a light magenta ink nozzle row20LM, a yellow ink nozzle row20Y, and a black ink nozzle row20K.

The cyan ink nozzle row20C includes the plurality of ink nozzles20arranged along the nozzle arrangement direction PD illustrated inFIG.3. The nozzle arrangement direction PD illustrated inFIG.3is the same as the conveyance direction TD, but this is not limitative. The nozzle arrangement direction PD is a direction different from the movement direction MD. The ink nozzle20included in the cyan ink nozzle row20C can eject cyan ink. The cyan ink is supplied to the printing head18from the ink tank or the ink cartridge not illustrated in the drawing. The cyan ink supplied to the printing head18is ejected by the ink nozzle20included in the cyan ink nozzle row20C.

The light cyan ink nozzle row20LC includes the plurality of ink nozzles20arranged along the nozzle arrangement direction PD. The ink nozzle20included in the light cyan ink nozzle row20LC can eject light cyan ink. The light cyan ink is supplied to the printing head18from the ink tank or the ink cartridge not illustrated in the drawing. The light cyan ink supplied to the printing head18is ejected by the ink nozzle20included in the light cyan ink nozzle row20LC.

The magenta ink nozzle row20M includes the plurality of ink nozzles20arranged along a nozzle arrangement direction PD. The ink nozzle20included in the magenta ink nozzle row20M can eject magenta ink. The magenta ink is supplied to the printing head18from the ink tank or the ink cartridge not illustrated in the drawing. The magenta ink supplied to the printing head18is ejected by the ink nozzle20included in the magenta ink nozzle row20M.

The light magenta ink nozzle row20LM includes the plurality of ink nozzles20arranged along the nozzle arrangement direction PD. The ink nozzle20included in the light magenta ink nozzle row20LM can eject light magenta ink. The light magenta ink is supplied to the printing head18from the ink tank or the ink cartridge not illustrated in the drawing. The light magenta ink supplied to the printing head18is ejected by the ink nozzle20included in the light magenta ink nozzle row20LM.

The yellow ink nozzle row20Y includes the plurality of ink nozzles20arranged along the nozzle arrangement direction PD. The ink nozzle20included in the yellow ink nozzle row20Y can eject yellow ink. The yellow ink is supplied to the printing head18from the ink tank or the ink cartridge not illustrated in the drawing. The yellow ink supplied to the printing head18is ejected by the ink nozzle20included in the yellow ink nozzle row20Y.

The black ink nozzle row20K includes the plurality of ink nozzles20arranged along the nozzle arrangement direction PD. The ink nozzle20included in the black ink nozzle row20K can eject black ink. The black ink is supplied to the printing head18from the ink tank or the ink cartridge not illustrated in the drawing. The black ink supplied to the printing head18is ejected by the ink nozzle20included in the black ink nozzle row20K.

The printing head18illustrated inFIG.3can eject six types of ink, but this is not limitative. The printing head18may be configured to eject five or less types of ink, or seven or more types of ink. The number of the ink nozzles20included in each nozzle row illustrated inFIG.3is 14, but this is not limitative. The number of the ink nozzles20included in each nozzle row may be smaller than14, or may be greater than14. The number of the ink nozzles20included in each nozzle row may be appropriately set.

FIG.4is a diagram illustrating a block configuration of the printing apparatus10. The printing apparatus10includes a control unit30, a display unit40, a communication interface50, a conveyance mechanism60, a printing driving mechanism70, a printing head driving mechanism80, and a detection mechanism90.FIG.4illustrates interface as I/F.

The control unit30is a controller that controls each unit of the printing apparatus10. The control unit30includes a control processor such as central processing unit (CPU), a random access memory (RAM), a read only memory (ROM) and the like. The control unit30operates as a functional unit by executing a program using the control processor. The RAM and the ROM function as work areas. The control unit30corresponds to an example of a control unit.

The control unit30includes a storage unit37. The storage unit37stores various programs operated by the control unit30, and various data. The storage unit37stores a test pattern image and correction data described later and the like in the form of data. The RAM and the ROM may operate as the storage unit37, or a magnetic storage device such as a hard disk drive (HDD), a semiconductor memory and the like may be provided.

The control unit30functions as a printing control unit31, a read control unit33, and a data processing unit35by executing the program. The printing control unit31, the read control unit33, and the data processing unit35are functional units.

The printing control unit31controls the printing driving mechanism70and the printing head driving mechanism80. The printing control unit31can control the printing mechanism16by controlling the printing driving mechanism70and the printing head driving mechanism80. The printing control unit31prints an image on the printing medium M. The printing control unit31acquires printing data. The printing data is stored in the storage unit37. Alternatively, the printing data is acquired from the external apparatus through the communication interface50. The printing control unit31controls the printing driving mechanism70and the printing head driving mechanism80so as to print an image on the printing medium M on the basis of the printing data.

The read control unit33controls the reading sensor15included in the detection mechanism90. The read control unit33controls the reading sensor15so as to read the image printed on the printing medium M. The read image is the test pattern image and the like. With the reading sensor15, the read control unit33receives the read read data from the reading sensor15. The received read data is transmitted to the data processing unit35.

The data processing unit35executes a computation of various data on the basis of the data detected by the detection mechanism90. The data processing unit35receives the read data read by the reading sensor15, and performs the computation using the data. When the received read data is the read data of the test pattern image, the data processing unit35performs generation of correction data, determination of the defective nozzle and the like on the basis of the read data. The data processing unit35corresponds to an example of a computation unit.

The display unit40displays various indications under the control of the control unit30. The display unit40includes a display. The display is composed of a liquid crystal display, an organic electro-luminescence (EL) or the like. The display may have a touch input function. The display unit40displays a setting screen for various settings such as printing conditions, an instruction screen for instructing printing, and the like.

The communication interface50is communicatively connected to an external apparatus. The communication interface50connects to the external apparatus in a wired or wireless manner in accordance with a predetermined communication protocol. The communication interface50receives printing data, a printing setting condition, a program and the like from the external apparatus. The communication interface50transmits the printing result, the maintenance data and the like of the printing apparatus10to the external apparatus.

The conveyance mechanism60conveys the printing medium M in the conveyance direction TD, or the direction opposite to the conveyance direction TD. The conveyance mechanism60includes the feed shaft11, the feed roller pair13, the conveyance roller pair25, and the winding shaft27. The conveyance mechanism60conveys the printing medium M under the control of the printing control unit31or the read control unit33. When the printing apparatus10performs printing on the printing medium M, the conveyance mechanism60conveys the printing medium M in the conveyance direction TD under the control of the printing control unit31. When the reading sensor15reads the test pattern image printed on the printing medium M, the conveyance mechanism60conveys the printing medium M in the direction opposite to the conveyance direction TD under the control of the read control unit33.

The printing driving mechanism70drives the printing mechanism16. The printing driving mechanism70includes the carriage17, a carriage driving mechanism, and the carriage support shaft19. The printing driving mechanism70moves the carriage17in the movement direction MD. With the carriage17moving in the movement direction MD, the plurality of ink nozzles20included in the printing head18scan the printing medium M. With the carriage17, the printing mechanism16scans the plurality of ink nozzles20. The scanning ink nozzle20forms an image on the printing medium M by ejecting ink. In the case where the printing mechanism16is a line head, the printing driving mechanism70may operate as a correction mechanism for correcting skew of the printing medium M.

The printing head driving mechanism80controls the ink ejection of the ink nozzle20under the control of the printing control unit31. The printing head driving mechanism80includes a driving element such as a piezoelectric element disposed in the printing head18. Each ink nozzle20ejects ink through the driving of the printing head driving mechanism80. The printing head driving mechanism80performs printing on the printing medium M by driving the plurality of ink nozzles20. The printing head driving mechanism80may drive a predetermined ink nozzle20of the plurality of ink nozzles20as a test pattern nozzle. The test pattern nozzle is used when printing a test pattern image. The test pattern nozzle is not driven when printing an image other than the test pattern image. The test pattern nozzle is a nozzle dedicated to printing of the test pattern image. The test pattern nozzle corresponds to an example of an inspection nozzle. The ejection characteristics of the test pattern nozzle are acquired in advance at the time of factory shipment and the like. The acquired ejection characteristics are stored in the storage unit37. The ejection characteristics correspond to the condition of the test pattern nozzle. One or more test pattern nozzles may be disposed for each nozzle row.

The detection mechanism90detects various operations of the printing apparatus10, the presence/absence of the printing medium M and the like. The detection mechanism90includes various sensors such as the reading sensor15, and a paper detection sensor and an ink residual quantity sensor not illustrated in the drawing. The detection mechanism90is driven under the control of the control unit30. The reading sensor15reads the image printed on the printing medium M on the basis of the instruction of the read control unit33in the control unit30. The reading operation of the reading sensor15corresponds to the detection operation. The detection mechanism90transmits detection data detected by various sensors to the control unit30. The reading sensor15transmits the read data to the control unit30.

FIG.5schematically illustrates a test pattern image. The test pattern image is printed on the printing medium M under the control of the printing control unit31. The test pattern image is printed by the printing mechanism16, and thus formed on the printing medium M. The test pattern image is printed on the printing medium M when inspecting the ink ejection defect of the ink nozzle20. The test pattern image is printed at the time of power on of the printing apparatus10, at a predetermined time or time interval set in advance, at the time of receiving an instruction from the user, or the like. The test pattern image illustrated inFIG.5is printed by the ink nozzle20included in the cyan ink nozzle row20C. When the test pattern image is printed by the nozzle row other than the cyan ink nozzle row20C, the mode of the test pattern image is the same as the mode of the test pattern image printed by the cyan ink nozzle row20C. InFIG.5, the test pattern image printed by the nozzle row other than the cyan ink nozzle row20C is omitted.

FIG.5illustrates the cyan ink nozzle row20C including the plurality of ink nozzles20. Ten ink nozzles20are included in the cyan ink nozzle row20C illustrated inFIG.5, but this is not limitative. It suffices that three or more ink nozzles20are included in the cyan ink nozzle row20C. The number of ink nozzles20included in the nozzle row may be appropriately changed.

The ink nozzles20included in the cyan ink nozzle row20C illustrated inFIG.5are a first ink nozzle2001, a second ink nozzle2002, a third ink nozzle2003, a fourth ink nozzle2004, a fifth ink nozzle2005, a sixth ink nozzle2006, a seventh ink nozzle2007, an eighth ink nozzle2008, a ninth ink nozzle2009, and a tenth ink nozzle2010. Each of the first ink nozzle2001to the tenth ink nozzle2010prints the pattern image included in the test pattern image on the printing medium M.

The first ink nozzle2001prints a first pattern image PG1. The second ink nozzle2002prints a second pattern image PG2. The third ink nozzle2003prints a third pattern image PG3. The fourth ink nozzle2004prints a fourth pattern image PG4. The fifth ink nozzle2005prints a fifth pattern image PG5. The sixth ink nozzle2006prints a sixth pattern image PG6. The seventh ink nozzle2007prints a seventh pattern image PG7. The eighth ink nozzle2008prints an eighth pattern image PG8. The ninth ink nozzle2009prints a ninth pattern image PG9. The tenth ink nozzle2010prints a tenth pattern image PG10.

FIG.5illustrates each ink nozzle20included in the cyan ink nozzle row20C at a position corresponding to each pattern image. When each ink nozzle20included in the cyan ink nozzle row20C performs single scanning in the movement direction MD with the carriage17, each pattern image illustrated inFIG.5is printed. InFIG.5, the movement direction MD corresponds to the +X direction. The single scanning corresponds to an example of first scanning. When each ink nozzle20performs multiple scans, the printing apparatus10may print each pattern image. For example, when each ink nozzle20performs predetermined single scanning among multiple scans, the printing apparatus10prints the first pattern image PG1. When each ink nozzle20performs scanning different from the predetermined single scanning, the printing apparatus10may print the second pattern image PG2to the tenth pattern image PG10. The predetermined single scanning corresponds to an example of first scanning, and scanning different from the predetermined single scanning corresponds to an example of scanning different from the first scanning. Each pattern image illustrated inFIG.5is a continuous line image in the movement direction MD, but this is not limitative. Each pattern image may be a partially omitted line image such as a broken line. The configuration of the pattern image is not limited as long as the image enables the detection of ejection defects of the ink nozzle20. Preferably, the pattern image is a continuous line image. The length of each pattern image in the movement direction MD is the distance between both ends in the movement direction MD.

FIG.5illustrates a test pattern image of a case when there is no defective nozzle in the ink nozzles20of the first ink nozzle2001to the tenth ink nozzle2010. The first ink nozzle2001prints the first pattern image PG1with a first test pattern length L1in the movement direction MD. The first pattern image PG1is a first test pattern P1. The first test pattern P1corresponds to an example of a first pattern. The first test pattern length L1corresponds to an example of a first length. InFIG.5, among the ink nozzles20included in the cyan ink nozzle row20C, the first ink nozzle2001prints the first test pattern P1. The first ink nozzle2001corresponds to an example of a first nozzle. The second ink nozzle2002to the tenth ink nozzle2010print the second pattern image PG2to the tenth pattern image PG10, respectively. The pattern image lengths of the second pattern image PG2to the tenth pattern image PG10are shorter than the first test pattern length L1. The image group including the pattern images of the second pattern image PG2to the tenth pattern image PG10is a second test pattern P2. The second test pattern P2corresponds to an example of a second pattern. The second test pattern P2is composed of a plurality of pattern images within the range surrounded by the dotted line illustrated inFIG.5. The region surrounded by the dotted line illustrated inFIG.5is a second test pattern region P2E. The second test pattern region P2E corresponds to an example of a region on a medium where a second pattern is formed.

The second test pattern P2includes the pattern images of the second pattern image PG2to the tenth pattern image PG10. The third pattern image PG3is printed with a displacement with respect to the second pattern image PG2in the movement direction MD and a longitudinal direction LD that intersects the movement direction MD. The longitudinal direction LD is a direction that intersects the width direction of the printing medium M. The longitudinal direction LD illustrated inFIG.5coincides with the conveyance direction TD and the +Y direction. The longitudinal direction LD corresponds to an example of a second direction. The fourth pattern image PG4is printed with a displacement with respect to the second pattern image PG2and the third pattern image PG3in the movement direction MD and the longitudinal direction LD. The fifth pattern image PG5and the eighth pattern image PG8are printed with a displacement with respect to the second pattern image PG2in the longitudinal direction LD. The sixth pattern image PG6and the ninth pattern image PG9are printed with a displacement with respect to the third pattern image PG3in the longitudinal direction LD. The seventh pattern image PG7and the tenth pattern image PG10are printed with a displacement with respect to the fourth pattern image PG4in the longitudinal direction LD. The printing positions of the second pattern image PG2, the third pattern image PG3and the fourth pattern image PG4are an arrangement of a step form with a displacement in the movement direction MD and the longitudinal direction LD. The printing positions of the fifth pattern image PG5, the sixth pattern image PG6and the seventh pattern image PG7are an arrangement of a step form with a displacement in the movement direction MD and the longitudinal direction LD. The printing positions of the eighth pattern image PG8, the ninth pattern image PG9and the tenth pattern image PG10are an arrangement of a step form with a displacement in the movement direction MD and the longitudinal direction LD. The arrangement of the step form with the displacement in the movement direction MD and the longitudinal direction LD corresponds to an example of image arrangement of a step form with a displacement in the first direction and the second direction.

The second test pattern region P2E is a region with a second test pattern width L2along the movement direction MD and a second test pattern length along the longitudinal direction LD. The second test pattern width L2corresponds to an example of a second length. The second test pattern width L2is the distance between both ends of the second pattern image PG2to the tenth pattern image PG10in the movement direction MD. In the second test pattern P2illustrated inFIG.5, the second test pattern width L2is the distance between the −X direction end portion of the second pattern image PG2and the +X direction end portion of the fourth pattern image PG4. The second test pattern length illustrated inFIG.5is the distance between the −Y direction end portion of the second pattern image PG2and the +Y direction end portion of the tenth pattern image PG10.

The second test pattern P2is printed by the ink nozzles20of the second ink nozzle2002to the tenth ink nozzle2010. The ink nozzles20of the second ink nozzle2002to the tenth ink nozzle2010correspond to an example of two or more nozzles different from the first nozzle. With nine ink nozzles20of the ink nozzles20included in the cyan ink nozzle row20C illustrated inFIG.5, the printing apparatus10prints the second test pattern P2. The number of ink nozzles20for printing the second test pattern P2is not limited to nine. It suffices that the number of ink nozzles20for printing the second test pattern P2is two or more. The number of ink nozzles20for printing the second test pattern P2may be appropriately changed.

As illustrated inFIG.5, the first test pattern length L1is longer than the second test pattern width L2. The printing apparatus10can accurately determine the defective nozzle by printing the test pattern image including the first test pattern P1and the second test pattern P2.

FIG.6,FIG.7andFIG.8illustrate an example of the test pattern image printed by the printing apparatus10. As inFIG.5,FIG.6,FIG.7andFIG.8illustrate the test pattern image printed by the cyan ink nozzle row20C. As inFIG.5,FIG.6,FIG.7andFIG.8illustrate the ink nozzle20corresponding to each pattern image included in the test pattern image.

FIG.6illustrates a test pattern image in which the printing position of the sixth pattern image PG6is different from the printing position of the sixth pattern image PG6included in the test pattern image illustrated inFIG.5.FIG.6illustrates a virtual sixth pattern image VPG6representing the printing position of the sixth pattern image PG6illustrated inFIG.5.

As illustrated inFIG.6, the printed sixth pattern image PG6and the virtual sixth pattern image VPG6are displaced by a sixth distance d6along the longitudinal direction LD. The first pattern image PG1that is the first test pattern P1is printed as a straight line. When the first pattern image PG1and the sixth pattern image PG6are printed through single scanning of the cyan ink nozzle row20C, a part of the first pattern image PG1and the sixth pattern image PG6are printed at the same timing. Since the first pattern image PG1is printed as a straight line, the printing apparatus10can determine that a jetting curve is caused at the sixth ink nozzle2006that prints the sixth pattern image PG6.

In some cases, the printing apparatus10prints the first pattern image PG1through predetermined single scanning of the cyan ink nozzle row20C, and prints the sixth pattern image PG6through scanning of the cyan ink nozzle row20C different from the predetermined single scan. A part of the first pattern image PG1and the sixth pattern image PG6are printed at the same position in the movement direction MD. For example, in the case where waviness is caused in the carriage support shaft19, the first pattern image PG1becomes a line image affected by the waviness. Since the first pattern image PG1illustrated inFIG.6is printed as a straight line, the printing apparatus10can determine that a jetting curve is caused at the sixth ink nozzle2006that prints the sixth pattern image PG6.

FIG.7illustrates a test pattern image in which the printing positions of the third pattern image PG3, the sixth pattern image PG6, and the ninth pattern image PG9are different from the printing positions of the third pattern image PG3, the sixth pattern image PG6, and the ninth pattern image PG9included in the test pattern image illustrated inFIG.5. FIG.7illustrates a virtual third pattern image VPG3, the virtual sixth pattern image VPG6, and a virtual ninth pattern image VPG9. The virtual third pattern image VPG3indicates the printing position of the third pattern image PG3illustrated inFIG.5. The virtual sixth pattern image VPG6indicates the printing position of the sixth pattern image PG6illustrated inFIG.5. The virtual ninth pattern image VPG9indicates the printing position of the ninth pattern image PG9illustrated inFIG.5. The test pattern image illustrated inFIG.7is printed on the printing medium M through single scanning of the cyan ink nozzle row20C.

As illustrated inFIG.7, the printed third pattern image PG3and the virtual third pattern image VPG3are displaced by a third distance d3along the longitudinal direction LD. The printed sixth pattern image PG6and the virtual sixth pattern image VPG6are displaced by the sixth distance d6along the longitudinal direction LD. The printed ninth pattern image PG9and the virtual ninth pattern image VPG9are displaced by a ninth distance d9along the longitudinal direction LD. As illustrated inFIG.7, a part of the first pattern image PG1is displaced by a first distance d1along the longitudinal direction LD with respect to the other region of the first pattern image PG1. A part of the first pattern image PG1whose printing position is displaced is hereinafter referred to as first pattern displacement image PG1d. The printing position of the first pattern displacement image PG1dcorresponds to the printing positions of the third pattern image PG3, the sixth pattern image PG6, and the ninth pattern image PG9. The first pattern displacement image PG1dis printed at the same timing as the third pattern image PG3, the sixth pattern image PG6, and the ninth pattern image PG9. As an example, the first distance d1, the third distance d3, the sixth distance d6, and the ninth distance d9illustrated inFIG.7are the same value within a range of the error. In this case, the test pattern image illustrated inFIG.7indicates that vibration is caused at the printing mechanism16when the first pattern displacement image PG1dis printed. Vibration occurs at the printing mechanism16due to factors such as shocks to the printing apparatus10and vibration generated in the vicinity of the location where the printing apparatus10is installed and the like. With the test pattern image illustrated inFIG.7, the printing apparatus10can determine the presence or absence and degree of the influence of disturbances on the printing apparatus10.

FIG.8illustrates a test pattern image in which the third pattern image PG3is not printed.FIG.8illustrates the virtual third pattern image VPG3indicating the printing position of the third pattern image PG3illustrated inFIG.5. The test pattern image illustrated inFIG.8indicates that the third ink nozzle2003that prints the third pattern image PG3is in a state where it cannot eject the ink. With the test pattern image illustrated inFIG.8, the printing apparatus10can determine that an ink ejection defect is caused at the third ink nozzle2003.

As described above, the printing apparatus10includes the printing mechanism16that moves with respect to the printing medium M in the movement direction MD and can eject ink, and the control unit30that can control the printing mechanism16. The printing mechanism16includes the plurality of ink nozzles20that are arranged in the nozzle arrangement direction PD different from the movement direction MD and can eject ink. The control unit30uses the first ink nozzle2001among the plurality of ink nozzles20to print the first test pattern P1with the first test pattern length L1in the movement direction MD, and uses two or more ink nozzles20different from the first ink nozzle2001to print the second test pattern P2including the image arrangement of a step form with a displacement in the movement direction MD and the longitudinal direction LD different from the movement direction MD, the second test pattern region P2E where the second test pattern P2is printed on the printing medium M has the second test pattern width L2in the movement direction MD, and the first test pattern length L1is greater than the second test pattern width L2.

By determining whether the first test pattern P1and the second test pattern P2have equivalent displacement of the ink impinging position at the same position in the movement direction MD, the presence/absence of print blur due to vibration and waviness of the carriage support shaft19can be acquired. With the combination of the first test pattern P1and the second test pattern P2, the printing apparatus10can estimate the ink impinging position, with the influence of the waviness of the carriage support shaft19and the print blur eliminated.

The printing mechanism16includes the carriage17that causes the plurality of ink nozzles20to perform scanning in the movement direction MD, and, when the carriage17performs a single scan, the control unit30causes it to form the first test pattern P1and the second test pattern P2.

The printing apparatus10can form a test pattern image that enables the detection of print blur due to reception of a sudden external force such as vibration applied to the printing apparatus10in addition to waviness of the carriage support shaft19.

The printing mechanism16includes the carriage17that performs scanning of the plurality of ink nozzles20in the movement direction MD. When the carriage17performs a single scan, the control unit30causes it to form the first test pattern P1, and when the carriage17performs scanning different from the single scanning, the control unit30causes it to form the second test pattern P2.

The printing apparatus10can provide a sufficient distance and drying time between the first test pattern P1and the second test pattern P2. The printing apparatus10can form a test pattern image that suppresses a situation where the second test pattern P2is erroneously detected as being not ejected due to the first test pattern P1and the second test pattern P2that have spread and merged with each other.

The first ink nozzle2001that prints the first test pattern P1may be used when printing an image, or may be used as the test pattern nozzle. The ink nozzles20of the second ink nozzle2002to the tenth ink nozzle2010print images. The ejection characteristics are measured in advance for the plurality of ink nozzles20included in the nozzle row. The ejection characteristics are, for example, the linearity of printing, the stability of ink ejection rate, and the like. The ink nozzle20with the highest ejection characteristics among the ink nozzles20whose ejection characteristics are measured may be stored in the storage unit37as a dedicated nozzle for printing the first test pattern P1. The printing apparatus10may control the ink nozzle20with the highest ejection characteristics as the ink nozzle20for printing the first test pattern P1on the basis of the information stored in the storage unit37.

Preferably, the first ink nozzle2001is an inspection nozzle whose condition is acquired in advance. When the ejection characteristics of the first ink nozzle2001used for the printing of the first test pattern P1are secured, the printing apparatus10can make an evaluation including the influence of jetting curve for other ink nozzles20different from the first ink nozzle2001.

FIG.9schematically illustrates another test pattern image. The test pattern image illustrated inFIG.9is printed under the control of the printing control unit31, and thus formed on the printing medium M. The test pattern image illustrated inFIG.9is printed by the ink nozzle20included in the cyan ink nozzle row20C.FIG.9illustrates the cyan ink nozzle row20C. When the test pattern image is printed by the nozzle row other than the cyan ink nozzle row20C, the mode of the test pattern image is the same as the mode of the test pattern image printed by the cyan ink nozzle row20C. InFIG.9, the test pattern image printed by the nozzle row other than the cyan ink nozzle row20C is omitted.

The cyan ink nozzle row20C illustrated inFIG.9includes eleven ink nozzles20of the first ink nozzle2001to an eleventh ink nozzle2011. The cyan ink nozzle row20C illustrated inFIG.9has the same configuration as the cyan ink nozzle row20C illustrated inFIG.5except that the number of ink nozzles20differs. Each of the first ink nozzle2001to the eleventh ink nozzle2011prints the pattern image included in the test pattern image on the printing medium M.

The first ink nozzle2001to the tenth ink nozzle2010illustrated inFIG.9print the first pattern image PG1to the tenth pattern image PG10illustrated inFIG.5. The eleventh ink nozzle2011prints an eleventh pattern image PG11. As illustrated inFIG.9, the first ink nozzle2001to the eleventh ink nozzle2011are arranged from the upstream side to the downstream side in the conveyance direction TD of the printing medium M. The conveyance direction TD illustrated inFIG.9coincides with the nozzle arrangement direction PD and the longitudinal direction LD of the ink nozzle20. The first ink nozzle2001is disposed most upstream in the conveyance direction TD. Among the plurality of pattern images, the first pattern image PG1is located most upstream in the printing medium M. The eleventh ink nozzle2011is disposed most downstream in the conveyance direction TD. The eleventh pattern image PG11is located most downstream among the plurality of pattern images in the printing medium M. The first ink nozzle2001and the eleventh ink nozzle2011are located at both ends in the conveyance direction TD.

FIG.9illustrates a test pattern image of a case where there is no defective nozzle in the ink nozzles20of the first ink nozzle2001to the eleventh ink nozzle2011. The first ink nozzle2001prints the first pattern image PG1with a first test pattern length L1in the movement direction MD. The eleventh ink nozzle2011prints the eleventh pattern image PG11with the first test pattern length L1in the movement direction MD. Each of the first pattern image PG1and the eleventh pattern image PG11is the first test pattern P1. InFIG.9, each of the first ink nozzle2001and the eleventh ink nozzle2011among the ink nozzles20included in the cyan ink nozzle row20C prints the first test pattern P1. The eleventh ink nozzle2011corresponds to an example of a second nozzle. The second ink nozzle2002to the tenth ink nozzle2010print the second pattern image PG2to the tenth pattern image PG10, respectively. The pattern image lengths of the second pattern image PG2to the tenth pattern image PG10are shorter than the first test pattern length L1. The image group including the pattern images of the second pattern image PG2to the tenth pattern image PG10is a second test pattern P2. The second test pattern P2illustrated inFIG.9is the same as the second test pattern P2illustrated inFIG.5.

After printing the test pattern image on the printing medium M with the printing mechanism16, the printing apparatus10illustrated inFIG.1conveys the printing medium M in the direction opposite to the conveyance direction TD. The printing medium M is conveyed from the printing mechanism16to the reading sensor15. The direction opposite to the conveyance direction TD corresponds to an example of a third direction. The printing medium M moves relative to the reading sensor15. The reading sensor15sequentially reads a plurality of pattern images included in the test pattern image printed on the printing medium M that is being conveyed. In the case of the test pattern image illustrated inFIG.9, the reading sensor15reads the first pattern image PG1, the second pattern image PG2, the third pattern image PG3, the fourth pattern image PG4, the fifth pattern image PG5, the sixth pattern image PG6, the seventh pattern image PG7, the eighth pattern image PG8, the ninth pattern image PG9, the tenth pattern image PG10, and the eleventh pattern image PG11in this order. The reading sensor15reads the test pattern image the first test pattern P1, the second test pattern P2, and the first test pattern P1in this order. The test pattern images illustrated inFIG.9are configured and arranged such that the reading sensor15reads the first test pattern P1before the second test pattern P2.

The printing medium M moves relative to the reading sensor15. The control unit30forms the first test pattern P1and the second test pattern P2in an arrangement in which the first test pattern P1is read by the reading sensor15before the second test pattern P2.

The first test pattern P1is sent to the reading sensor15before the second test pattern P2, and thus the printing apparatus10can detect the presence/absence of waviness and vibration in advance.

The test pattern image illustrated inFIG.9may be used for the printing apparatus10that differs from the printing apparatus10illustrated inFIG.1in arrangement of the reading sensor15. The test pattern image illustrated inFIG.9may be used for the printing apparatus10in which the reading sensor15is disposed between the printing mechanism16and the conveyance roller pair25, for example. The printing apparatus10in which the reading sensor15is disposed downstream of the printing mechanism16prints the test pattern image at the printing mechanism16and thereafter conveys the printing medium M in the conveyance direction TD. The reading sensor15sequentially reads a plurality of pattern images included in the test pattern image printed on the printing medium M conveyed in the conveyance direction TD. In this case, the conveyance direction TD corresponds to an example of a third direction. The reading sensor15reads the eleventh pattern image PG11, the tenth pattern image PG10, the ninth pattern image PG9, the eighth pattern image PG8, the seventh pattern image PG7, the sixth pattern image PG6, the fifth pattern image PG5, the fourth pattern image PG4, the third pattern image PG3, the second pattern image PG2, and the first pattern image PG1in this order. The reading sensor15reads the test pattern image the first test pattern P1, the second test pattern P2, and the first test pattern P1in this order.

The printing medium M moves relative to the reading sensor15. By using the eleventh ink nozzle2011different from the first ink nozzle2001, the control unit30prints the first test pattern P1different from the first test pattern P1printed by using the first ink nozzle2001. The control unit30prints the second test pattern P2by using two or more ink nozzles20different from the first ink nozzle2001and the eleventh ink nozzle2011. The first ink nozzle2001and the eleventh ink nozzle2011are located at both ends in the conveyance direction TD in the plurality of ink nozzles20.

The designer of the printing apparatus10can use the test pattern image for the printing apparatus10with a different arrangement of the reading sensor15.

FIG.10illustrates a step of detecting a defective nozzle. The printing apparatus10prints the test pattern image illustrated inFIG.5orFIG.9on the printing medium M. The printing apparatus10reads the test pattern image printed on the printing medium M with the reading sensor15. The printing apparatus10detects the defective nozzle on the basis of the data read by the reading sensor15.FIG.10illustrates a step in which the printing apparatus10prints the test pattern image and thereafter detects the defective nozzle on the basis of the reading result of the printed test pattern image.

At step S101, the printing apparatus10prints the test pattern image. The method of printing the test pattern image corresponds to an example of a recording method. The printing apparatus10illustrated inFIG.1moves the printing mechanism16in the movement direction MD illustrated inFIG.3relative to the printing medium M. The printing mechanism16includes the printing head18including the plurality of ink nozzles20. The plurality of ink nozzles20make up a nozzle row arranged in the nozzle arrangement direction PD different from the movement direction MD. One nozzle row can eject ink of one color. The printing apparatus10moves the printing medium M relative to the printing mechanism16. The printing apparatus10causes the plurality of ink nozzles20moving in the movement direction MD to scanning the printing medium M. The scanning plurality of ink nozzles20prints the test pattern image by ejecting ink to the printing medium M. The printing apparatus10forms the test pattern image on the printing medium M by printing the test pattern image with the printing mechanism16.

The printing apparatus10prints the test pattern image on the printing medium M under the control of the control unit30. With the printing mechanism16, the control unit30prints the test pattern image including the first test pattern P1and the second test pattern P2on the printing medium M. As illustrated inFIG.5, the control unit30prints the first test pattern P1with the first ink nozzle2001. As illustrated inFIG.5, the first test pattern P1is a pattern image with the first test pattern length L1in the movement direction MD. The second test pattern P2is composed of two or more pattern images printed by two or more ink nozzles20. As illustrated inFIG.5, the control unit30prints the second test pattern P2by using the second ink nozzle2002to the tenth ink nozzle2010. The second test pattern P2is printed in the second test pattern region P2E with the second test pattern width L2in the movement direction MD and the second test pattern length in the longitudinal direction LD that intersects the movement direction MD. As illustrated inFIG.5, the two or more pattern images making up the second test pattern P2are printed in an arrangement including an image arrangement of a step form with a displacement in the movement direction MD and the longitudinal direction LD. The control unit30performs the printing in such a manner that the first test pattern length L1of the first test pattern P1is greater than the second test pattern width L2of the second test pattern P2.

The control unit30may print the first test pattern P1and the second test pattern P2through single scanning of the ink nozzle20with the carriage17, or through multiple scans of the ink nozzle20. By printing the first test pattern P1and the second test pattern P2through a single scan, the printing apparatus10can easily detect the vibration applied to the printing apparatus10. The printing apparatus10may print the first test pattern P1and the second test pattern P2at different scans. The printing apparatus10may print the first test pattern P1and the second test pattern P2at shifted times.

The printing method of the printing apparatus10moves the printing medium M in the movement direction MD relative to the printing mechanism16including the plurality of ink nozzles20, prints the first test pattern P1with the first test pattern length L1in the movement direction MD with the first ink nozzle2001among the plurality of ink nozzles20, and prints the second test pattern P2including an image arrangement of a step form with a displacement in the movement direction MD and the longitudinal direction LD that intersects the movement direction MD with two or more ink nozzles20different from the first ink nozzle2001among the plurality of ink nozzles20. The second test pattern region P2E on the printing medium M where the second test pattern P2is printed has the second test pattern width L2in the movement direction MD, and the first test pattern length L1is greater than the second test pattern width L2.

By determining whether the first test pattern P1and the second test pattern P2have equivalent displacement of the ink impinging position at the same position in the movement direction MD, and the presence/absence of waviness of the carriage support shaft19and print blur can be determined. With the combination of the first test pattern P1and the second test pattern P2, the printing apparatus10can estimate the ink impinging position, with the influence of the waviness and print blur eliminated.

After printing the test pattern image at step S101, the printing apparatus10reads the test pattern image at step S103. The printing apparatus10reads the test pattern image with the reading sensor15. The reading sensor15transmits the read data to the control unit30. The reading result includes first read data obtained by reading the first test pattern P1and second read data obtained by reading the second test pattern P2. The read data corresponds to an example of a detection result. The first read data corresponds to an example of detection data of a first pattern. The second read data corresponds to an example of detection data of a second pattern. The control unit30receives the read data.

After reading the test pattern image at step S103, the printing apparatus10generates correction data at step S105. The data processing unit35of the control unit30acquires the read data. As an example, the data processing unit35acquires read data obtained by reading the test pattern image illustrated inFIG.7. The data processing unit35extracts first read data from the read data. The data processing unit35evaluates the linearity of the first test pattern P1on the basis of the first read data. The data processing unit35determines whether the first pattern displacement image PG1dis included in the first test pattern P1. The test pattern image illustrated inFIG.7includes the first pattern displacement image PG1d, and therefore the data processing unit35determines that the first pattern displacement image PG1dis included. When the data processing unit35determines that the first pattern displacement image PG1dis included, the data processing unit35calculates the displacement amount of the first pattern displacement image PG1d. The displacement amount of the first pattern displacement image PG1dis a shift amount with respect to the first pattern image PG1different from the first pattern displacement image PG1d. The displacement amount of the first pattern displacement image PG1dis the first distance d1illustrated inFIG.7. The data processing unit35calculates the first distance d1as correction data. The correction data corresponds to an example of a correction value.

After calculating the correction data at step S105, the printing apparatus10corrects the second read data at step S107. In the test pattern image illustrated inFIG.7, the first pattern displacement image PG1dis printed at the same timing, or at the same position in the movement direction MD, as the third pattern image PG3, the sixth pattern image PG6, and the ninth pattern image PG9. The third pattern image PG3is displaced by the third distance d3with respect to the virtual third pattern image VPG3. The sixth pattern image PG6is displaced by the sixth distance d6with respect to the virtual sixth pattern image VPG6. The ninth pattern image PG9is displaced by the ninth distance d9with respect to the virtual ninth pattern image VPG9. The data processing unit35corrects the third distance d3, the sixth distance d6, and the ninth distance d9by the first distance d1. As an example, the data processing unit35calculates the difference between the first distance d1and the third distance d3, the difference between the first distance d1and the sixth distance d6, and the difference between the first distance d1and the ninth distance d9. The data processing unit35may perform the correction by using a computational expression stored in advance in the storage unit37. The result obtained by correcting the third distance d3by the first distance d1is hereinafter referred to as third displacement amount. The result obtained by correcting the sixth distance d6by the first distance d1is hereinafter referred to as sixth displacement amount. The result obtained by correcting the ninth distance d9by the first distance d1is hereinafter referred to as ninth displacement amount.

After correcting the second read data at step S107, the printing apparatus10specifies the defective nozzle at step S109. The data processing unit35reads a threshold value stored in the storage unit37. The threshold value is an index indicating whether the jetting curve and/or the waviness of the carriage support shaft19is within the acceptable range. The data processing unit35compares the threshold value, with each of the third displacement amount, the sixth displacement amount, and the ninth displacement amount. For example, when the third displacement amount is greater than the threshold value, the data processing unit35determines that the third ink nozzle2003is a defective nozzle. When the sixth displacement amount and the ninth displacement amount are smaller than the threshold value, the data processing unit35determines that the sixth ink nozzle2006and the ninth ink nozzle2009are not the defective nozzle. By comparing the threshold value and the displacement amount, the data processing unit35specifies the defective nozzle.

The printing apparatus10includes the reading sensor15that reads the first test pattern P1and the second test pattern P2printed on the printing medium M, and the data processing unit35that executes a computation on the basis of the read data of the reading sensor15. The data processing unit35calculates the correction data on the basis of the first read data included in the read data, and specifies the defective nozzle on the basis of the second read data included in the correction data and the read data.

By correcting the print blur due to vibration and the waviness of the carriage support shaft19, the printing apparatus10can specify the defective nozzle with less errors.

FIG.11schematically illustrates a test pattern image printed by using a line head for the printing mechanism16. The test pattern image is printed on the printing medium M under the control of the printing control unit31. The test pattern image is printed by the printing mechanism16, and thus formed on the printing medium M. The test pattern image illustrated inFIG.11is printed by the ink nozzle20included in the cyan ink nozzle row20C. When the test pattern image is printed by the nozzle row other than the cyan ink nozzle row20C, the mode of the test pattern image is the same as the mode of the test pattern image printed by the cyan ink nozzle row20C. InFIG.11, the test pattern image printed by the nozzle row other than the cyan ink nozzle row20C is omitted.

FIG.11illustrates the cyan ink nozzle row20C including the ink nozzle20. The cyan ink nozzle row20C illustrated inFIG.11includes n ink nozzles20. The n is an integer of 8 or greater. It suffices that three or more ink nozzles20are included in the cyan ink nozzle row20C. The number of ink nozzles20may be appropriately changed.

The ink nozzles20included in the cyan ink nozzle row20C illustrated inFIG.11is the first ink nozzle2001to the nth ink nozzle N. Each of the first ink nozzle2001to the nth ink nozzle N prints the pattern image included in the test pattern image on the printing medium M.

The first ink nozzle2001prints a first pattern image PG1. The second ink nozzle2002prints a second pattern image PG2. The third ink nozzle2003prints a third pattern image PG3. The fourth ink nozzle2004prints a fourth pattern image PG4. The fifth ink nozzle2005prints a fifth pattern image PG5. The sixth ink nozzle2006prints a sixth pattern image PG6. The seventh ink nozzle2007prints a seventh pattern image PG7. The nth ink nozzle N prints the nth pattern image PGn.

FIG.11illustrates the ink nozzles20at positions corresponding to pattern images. Each pattern image illustrated inFIG.11is printed when the printing medium M is moved in the conveyance direction TD with respect to the cyan ink nozzle row20C. InFIG.11, the conveyance direction TD corresponds to the +Y direction. In the configuration illustrated inFIG.11, the conveyance direction TD corresponds to an example of a first direction.

The first ink nozzle2001prints the first pattern image PG1with the first test pattern length L1in the conveyance direction TD. The first pattern image PG1is a first test pattern P1. The first test pattern P1corresponds to an example of a first pattern. The first test pattern length L1corresponds to an example of a first length. InFIG.11, among the ink nozzles20included in the cyan ink nozzle row20C, the first ink nozzle2001prints the first test pattern P1. The first ink nozzle2001corresponds to an example of a first nozzle. The second ink nozzle2002to the nth ink nozzle N print the second pattern image PG2to the nth pattern image PGn. The pattern image lengths of the second pattern image PG2to the nth pattern image PGn are shorter than the first test pattern length L1. The image group including the pattern images of the second pattern image PG2to the nth pattern image PGn is the second test pattern P2. The second test pattern P2corresponds to an example of a second pattern. The second test pattern P2is composed of a plurality of pattern images within the range surrounded by the dotted line illustrated inFIG.11. The region surrounded by the dotted line illustrated inFIG.11is the second test pattern region P2E. The second test pattern region P2E corresponds to an example of a region on a medium where a second pattern is formed.

The second test pattern P2includes the pattern images of the second pattern image PG2to the nth pattern image PGn. The third pattern image PG3is printed with a displacement with respect to the second pattern image PG2in the conveyance direction TD and a width direction WD that intersects the conveyance direction TD. The width direction WD is a direction corresponding to the width of the printing medium M. The width direction WD illustrated inFIG.11corresponds to the +X direction. The width direction WD corresponds to an example of a second direction. The fourth pattern image PG4is printed with a displacement with respect to the second pattern image PG2and the third pattern image PG3in the conveyance direction TD and the width direction WD. The printing positions of the second pattern image PG2to the sixth pattern image PG6are an image arrangement of a step form with a displacement in the conveyance direction TD and the width direction WD. The arrangement of a step form with a displacement in the conveyance direction TD and the width direction WD corresponds to an example of an image arrangement of a step form with a displacement in the first direction and the second direction. The seventh pattern image PG7is printed with a displacement with respect to the second pattern image PG2in the width direction WD.

The second test pattern region P2E is a region with the second test pattern width L2in the conveyance direction TD and the second test pattern length along the width direction WD. The second test pattern width L2corresponds to an example of a second length. The second test pattern width L2is the distance between both ends of the second pattern image PG2to the nth pattern image PGn in the conveyance direction TD. In the second test pattern P2illustrated inFIG.11, the second test pattern width L2is the distance between the −Y direction end portion of the second pattern image PG2and the +Y direction end portion of the sixth pattern image PG6. The second test pattern length is the distance between the −X direction end portion of the second pattern image PG2and the +X direction end portion of the nth pattern image PGn.

The second test pattern P2is printed by the ink nozzles20of the second ink nozzle2002to the nth ink nozzle N. The ink nozzles20of the second ink nozzle2002to the nth ink nozzle N correspond to an example of two or more nozzles different from the first nozzle. It suffices that the number of ink nozzles20for printing the second test pattern P2is two or more. The number of ink nozzles20for printing the second test pattern P2may be appropriately changed.

As illustrated inFIG.11, the first test pattern length L1is greater than the second test pattern width L2. The printing apparatus10can accurately determine the defective nozzle by printing the test pattern image including the first test pattern P1and the second test pattern P2.

FIG.11illustrates the reading sensor15that reads the test pattern image. The reading sensor15illustrated inFIG.11moves in a read direction RD illustrated inFIG.11. When moving in the read direction RD, the reading sensor15reads the test pattern image. The read direction RD is a direction that intersects the conveyance direction TD. The read direction RD illustrated inFIG.11coincides with the width direction WD. The read direction RD corresponds to an example of a third direction. The reading sensor15reads the pattern images arranged in the width direction WD, the first pattern image PG1, the second pattern image PG2, and the third pattern image PG3in this order.

As illustrated inFIG.11, the test pattern image can be applied to the printing apparatus10using a line head for the printing mechanism16.