LIQUID EJECTION DEVICE, IMAGE PROCESSING METHOD, AND IMAGE PROCESSING PROGRAM

Abstract

To solve the problem that detection accuracy of a position detection mark occasionally deteriorates depending on a positional relation between a position detection mark used in position detection and an adjacent image or a color of an image adjacent to the position detection mark.SOLUTION: A liquid discharge device includes a printing part for printing an inspection image, a read-out part for reading out the inspection image printed by the printing part, and an analysis part for analyzing the inspection image on the basis of the read-out result read out by the read-out part, wherein the inspection image includes a first position detection mark printed with a first color, a second position detection mark printed with the first color, and a plurality of colors of inspection patterns including a second color inspection pattern printed with a second color different from the first color, the printing part prints the second color inspection pattern at a position adjacent to the first position detection mark, and the analysis part identifies a first position of the first position detection mark in a first region, and identifies a second position of the second position detection mark in a second region narrower than the first region.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present disclosure relates to a liquid ejection apparatus, an image processing method, and an image processing program. [Background technology]

[0002] An image processing method for determining recording defects using a recorded test pattern is known. The inkjet recording device of Patent Document 1 prints a non-discharge detection pattern including a detection mark. The detection mark is a mark used for position detection. The inkjet recording device reads the non-discharge detection pattern and performs non-discharge detection processing based on the reading results. The inkjet recording device determines which nozzles are faulty in ejection by performing the non-discharge detection processing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-3515 Summary of the Invention [Problem to be solved by the invention]

[0004] The detection accuracy of the detection mark may be reduced due to the positional relationship between the position detection mark used for position detection and the adjacent image, or due to the influence of the color of the image adjacent to the position detection mark. [Means for solving the problem]

[0005] The liquid ejection device disclosed herein comprises a printing unit that prints a test image, a reading unit that reads the test image printed by the printing unit, and an analysis unit that analyzes the test image based on the reading results read by the reading unit, wherein the test image has a multi-color test pattern including a first position detection mark printed in a first color, a second position detection mark printed in the first color, and a second color test pattern printed in a second color different from the first color, the printing unit prints the second color test pattern at a position adjacent to the first position detection mark, and the analysis unit identifies a first position of the first position detection mark in a first area and identifies a second position of the second position detection mark in a second area narrower than the first area.

[0006] The image processing method disclosed herein prints an inspection image having a multi-color inspection pattern including a first position detection mark formed in a first color, a second position detection mark formed in the first color, and a second color inspection pattern formed in a second color different from the first color, with the second color inspection pattern positioned adjacent to the first position detection mark, reads the inspection image to obtain a reading result, identifies a first position of the first position detection mark in a first area, and identifies a second position of the second position detection mark in a second area narrower than the first area.

[0007] An image processing program executed by a processor of a liquid ejection device that prints the inspection image of the present disclosure, the image processing program causing the inspection image having a multi-color inspection pattern including a first position detection mark formed in a first color, a second position detection mark formed in the first color, and a second color inspection pattern formed in a second color different from the first color, to be printed by positioning the second color inspection pattern in a position adjacent to the first position detection mark, reading the inspection image to obtain the reading results, determining a first position of the first position detection mark in a first area, and determining a second position of the second position detection mark in a second area narrower than the first area. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing a schematic configuration of a printing apparatus. [Figure 2] FIG. 1 is a diagram showing a schematic configuration of a printing apparatus. [Figure 3] FIG. 2 is a diagram showing the relationship between a print medium and a print head. [Figure 4] FIG. 2 is a diagram showing functional blocks of the printing apparatus. [Figure 5] FIG. 10 is a diagram showing an outline of a test pattern image. [Figure 6] FIG. 10 is an enlarged view of a test pattern image including a first mark. [Figure 7] FIG. 4 is a diagram showing the concentration distribution in the first measurement region. [Figure 8] FIG. 10 is an enlarged view of a test pattern image including a second mark. [Figure 9] FIG. 10 is a diagram showing the concentration distribution in the second measurement region. [Figure 10] FIG. 4 is a flowchart showing image processing performed by the printing device. [Figure 11] FIG. 10 is an enlarged view of a test pattern image including a third mark. DETAILED DESCRIPTION OF THE INVENTION

[0009] 1 and 2 show the schematic configuration of a printing device 10. FIG. 1 is a view of the printing device 10 as seen from the +X direction. FIG. 2 is a view of the printing device 10 as seen from the +Z direction. The printing device 10 prints on a printing medium M that is fed from a medium roll R1. The printing device 10 is an inkjet type that ejects ink onto the printing medium M. The printing device 10 corresponds to an example of a liquid ejection device. The printing medium M corresponds to an example of a medium.

[0010] Some figures, including FIG. 1, show an XYZ coordinate system. The X, Y, and Z axes are perpendicular to one another. The X axis is parallel to the installation surface of the printing apparatus 10. The X axis is parallel to the rotation axis of the medium roll R1 placed on the printing apparatus 10. The rotation axis of the medium roll R1 is the virtual center axis of rotation when the medium roll R1 rotates. The direction from the back to the front of FIG. 1 is the +X direction. The direction from the front to the back of FIG. 1 is the -X direction. The Y axis is parallel to the installation surface of the printing apparatus 10. The Y axis is an axis perpendicular to the rotation axis of the medium roll R1. The direction from right to left of the printing apparatus 10 shown in FIG. 1 is the +Y direction. The direction from left to right of the printing apparatus 10 shown in FIG. 1 is the -Y direction. The Z axis is an axis perpendicular to the installation surface of the printing apparatus 10. The direction from the installation surface upward is the +Z direction. The direction from above toward the installation surface is the -Z direction.

[0011] 1 and 2 show the various components arranged along the printing medium M. The printing device 10 shown in FIGS. 1 and 2 includes a feed shaft 11, a feed roller pair 13, a reading sensor 15, a printing mechanism 16, a transport roller pair 25, and a take-up shaft 27.

[0012] The payout spindle 11 supports a medium roll R1 on which the printing medium M is wound in a roll shape. The payout spindle 11 is supported so as to be rotatable. The payout spindle 11 may be connected to a rotation drive mechanism (not shown). The rotation drive mechanism rotates the payout spindle 11. The rotated payout spindle 11 pays out the printing medium M wound around the medium roll R1.

[0013] The pair of feed rollers 13 feeds the printing medium M toward the printing mechanism 16. The direction in which the printing medium M is transported at a position facing the printing mechanism 16 is hereinafter referred to as the transport direction TD. The pair of feed rollers 13 holds the printing medium M between them. The pair of feed rollers 13 has a first feed roller 13A and a second feed roller 13B. The first feed roller 13A is positioned in the +Z direction from the second feed roller 13B. The first feed roller 13A contacts the surface of the printing medium M on the +Z direction side. The second feed roller 13B contacts the surface of the printing medium M on the -Z direction side. The first feed roller 13A and the second feed roller 13B hold the printing medium M between them. One of the first feed roller 13A and the second feed roller 13B is connected to a drive mechanism (not shown). One of the first feed roller 13A and the second feed roller 13B is rotated by the driving force of the drive mechanism. The other of the first feed roller 13A and the second feed roller 13B is rotated by the driving force of the drive mechanism. The feed roller pair 13 feeds the printing medium M toward the printing mechanism 16 by the driving force of the drive mechanism. The feed roller pair 13 also transports the printing medium M in the direction opposite to the transport direction TD.

[0014] The reading sensor 15 reads the surface of the print medium M. The reading sensor 15 is composed of an image sensor such as a CIS (Contact Image Sensor) or a CCD (Charge Coupled Device). The reading sensor 15 shown in FIG. 1 reads the entire width of the print medium M parallel to the X-axis. In the printing device 10 shown in FIGS. 1 and 2, the reading sensor 15 reads the print medium M located between the pair of feed rollers 13 and the printing mechanism 16. The printing device 10 shown in FIGS. 1 and 2 transports the print medium M in the direction opposite to the transport direction TD. The reading sensor 15 reads the print medium M transported in the direction opposite to the transport direction TD. The reading sensor 15 reads an image such as a test pattern image 100 printed on the print medium M by the printing mechanism 16. The test pattern image 100 will be described later. The position of the reading sensor 15 is not limited to a position between the pair of feed rollers 13 and the printing mechanism 16. The reading sensor 15 may be disposed at a position between the printing mechanism 16 and the pair of transport rollers 25 on the transport path of the print medium M. The reading sensor 15 corresponds to an example of a reading unit.

[0015] The reading sensor 15 has a light-emitting unit and a light-receiving unit (not shown). The light-emitting unit emits red light, green light, and blue light by switching between them in sequence. The light-receiving unit receives the light reflected from the printing medium M when the light-emitting unit emits each color light. The received light data when the light-emitting unit emits red light is referred to as the red channel. The red channel is image data from which the red component has been extracted. The received light data when the light-emitting unit emits green light is referred to as the green channel. The received light data when the light-emitting unit emits blue light is referred to as the blue channel. The blue channel is image data from which the blue component has been extracted. The reading data generated by the reading sensor 15 is image data including the red channel, green channel, and blue channel. Any of the red channel, green channel, and blue channel corresponds to an example of the first channel and the second channel.

[0016] The printing mechanism 16 prints an image on the print medium M. The printing mechanism 16 forms an image by ejecting ink onto the print medium M. As shown in FIG. 1, the printing mechanism 16 includes a carriage 17 and a print head 18. The print head 18 has a plurality of ink nozzles 20. The printing mechanism 16 is supported by a carriage support shaft 19 shown in FIG. 2. The printing mechanism 16 shown in FIGS. 1 and 2 moves the carriage 17, but is not limited to this. The printing mechanism 16 may also be a line head type in which the print head 18 is fixed relative to the print medium M during printing. The printing mechanism 16 corresponds to an example of a printing unit. The ink corresponds to an example of a liquid.

[0017] The carriage 17 supports the print head 18. The carriage 17 moves along a carriage support shaft 19 shown in FIG. 2 in a movement direction MD or in a direction opposite to the movement direction MD. The movement of the carriage 17 causes the print mechanism 16 to move relative to the print medium M. The carriage support shaft 19 shown in FIG. 2 is parallel or approximately parallel to the X axis. The carriage 17 moves in the +X direction and the -X direction relative to the print medium M. The movement of the carriage 17 causes the print mechanism 16 to scan the ink nozzles 20 relative to the print medium M. As shown in FIG. 2, the +X direction is the movement direction MD and corresponds to an example of the first direction. The movement direction MD may also be the -X direction. The carriage 17 moves due to the driving force of a carriage drive mechanism (not shown). The carriage 17 corresponds to an example of an ejection unit drive mechanism. In the printing device 10 shown in FIGS. 1 and 2, the print mechanism 16 moves relative to the print medium M, but this is not limiting. The print mechanism 16 moves relative to the print medium M.

[0018] The print head 18 is supported by a carriage 17. The print head 18 has a plurality of ink nozzles 20 on a printing surface that faces the print medium M. The ink nozzles 20 are capable of ejecting ink onto the print medium M. The ink nozzles 20 correspond to an example of a nozzle. The configuration of the ink nozzles 20 will be described later. The print head 18 is supplied with ink of a plurality of colors from ink tanks or ink cartridges (not shown).

[0019] The carriage support shaft 19 movably supports the carriage 17. As shown in FIG. 2, the carriage support shaft 19 is supported by a first side plate 95 and a second side plate 97. The first side plate 95 is disposed at a position in the -X direction of the print medium M being transported. The second side plate 97 is disposed at a position in the +X direction of the print medium M being transported. The carriage support shaft 19 is supported along an axis that intersects with the Y axis. The carriage support shaft 19 shown in FIG. 2 is supported parallel or approximately parallel to the X axis. The first side plate 95 and the second side plate 97 may support the feed roller pair 13, the reading sensor 15, and the transport roller pair 25.

[0020] The transport roller pair 25 transports the print medium M printed by the printing mechanism 16. The transport roller pair 25 holds the print medium M between them. The transport roller pair 25 includes a first transport roller 25A and a second transport roller 25B. The first transport roller 25A is positioned in the +Z direction from the second transport roller 25B. The first transport roller 25A contacts the surface of the print medium M on the +Z direction side. The second transport roller 25B contacts the surface of the print medium M on the -Z direction side. The first transport roller 25A and the second transport roller 25B hold the print medium M between them. One of the first transport roller 25A and the second transport roller 25B may be connected to a drive mechanism (not shown). When connected to the drive mechanism, one of the first transport roller 25A and the second transport roller 25B rotates due to the drive force of the drive mechanism. The other of the first transport roller 25A and the second transport roller 25B is rotated by the drive mechanism. The transport roller pair 25 guides the print medium M to the take-up roll R2. The transport roller pair 25 may also transport the print medium M in the direction opposite to the transport direction TD.

[0021] The winding shaft 27 winds the printing medium M printed by the printing mechanism 16 onto the winding roll R2. The winding shaft 27 supports the winding roll R2. The winding shaft 27 is rotatably supported. The winding shaft 27 may be connected to a rotation drive mechanism (not shown). The rotation drive mechanism rotates the winding shaft 27. The rotated winding shaft 27 winds the printing medium M onto the winding roll R2. The winding shaft 27 may wind the printing medium M via a roll core (not shown).

[0022] 1 and 2 uses a printing medium M wound on a medium roll R1, but this is not limited to this. The printing device 10 may also use cut sheets cut to a predetermined size. When the printing device 10 uses cut sheets, the supply shaft 11 and take-up shaft 27 are replaced with a paper feed cassette and a paper output tray, respectively.

[0023] FIG. 3 shows the relationship between the print medium M and the print head 18. The carriage 17 and carriage support shaft 19 are omitted from FIG. 3. FIG. 3 also shows the reading sensor 15. The print head 18 shown in FIG. 3 moves in a movement direction MD to print an image on the print medium M. The movement direction MD shown in FIG. 3 corresponds to the +X direction. Multiple ink nozzles 20 are arranged on the printing surface of the print head 18 that faces the print medium M. The multiple ink nozzles 20 form multiple nozzle arrays. The ink nozzles 20 shown in FIG. 3 form a magenta ink nozzle array 20M, a light magenta ink nozzle array 20LM, a cyan ink nozzle array 20C, a light cyan ink nozzle array 20LC, a yellow ink nozzle array 20Y, and a black ink nozzle array 20K.

[0024] The magenta ink nozzle row 20M has a plurality of ink nozzles 20 arranged in a nozzle array direction PD. The nozzle array direction PD shown in FIG. 3 is the same direction as the transport direction TD, but is not limited to this. The nozzle array direction PD is a direction different from the movement direction MD. The ink nozzles 20 included in the magenta ink nozzle row 20M are capable of ejecting magenta ink. Magenta ink is a magenta-colored ink. The magenta ink is supplied to the print head 18 from an ink tank or ink cartridge (not shown). The magenta ink supplied to the print head 18 is ejected by the ink nozzles 20 included in the magenta ink nozzle row 20M.

[0025] The light magenta ink nozzle row 20LM has a plurality of ink nozzles 20 arranged along the nozzle arrangement direction PD. The ink nozzles 20 included in the light magenta ink nozzle row 20LM are capable of ejecting light magenta ink. Light magenta ink is a light magenta colored ink. The light magenta ink is supplied to the print head 18 from an ink tank or ink cartridge (not shown). The light magenta ink supplied to the print head 18 is ejected by the ink nozzles 20 included in the light magenta ink nozzle row 20LM.

[0026] The cyan ink nozzle row 20C has a plurality of ink nozzles 20 arranged along the nozzle arrangement direction PD shown in FIG. 3. The ink nozzles 20 included in the cyan ink nozzle row 20C are capable of ejecting cyan ink. Cyan ink is cyan-colored ink. The cyan ink is supplied to the print head 18 from an ink tank or ink cartridge (not shown). The cyan ink supplied to the print head 18 is ejected by the ink nozzles 20 included in the cyan ink nozzle row 20C.

[0027] The light cyan ink nozzle row 20LC has a plurality of ink nozzles 20 arranged along the nozzle arrangement direction PD. The ink nozzles 20 included in the light cyan ink nozzle row 20LC are capable of ejecting light cyan ink. Light cyan ink is ink of a light cyan color. The light cyan ink is supplied to the print head 18 from an ink tank or ink cartridge (not shown). The light cyan ink supplied to the print head 18 is ejected by the ink nozzles 20 included in the light cyan ink nozzle row 20LC.

[0028] The yellow ink nozzle row 20Y has a plurality of ink nozzles 20 arranged along the nozzle arrangement direction PD. The ink nozzles 20 included in the yellow ink nozzle row 20Y are capable of ejecting yellow ink. Yellow ink is ink of a yellow color. The yellow ink is supplied to the print head 18 from an ink tank or ink cartridge (not shown). The yellow ink supplied to the print head 18 is ejected by the ink nozzles 20 included in the yellow ink nozzle row 20Y.

[0029] The black ink nozzle row 20K has a plurality of ink nozzles 20 arranged in the nozzle arrangement direction PD. The ink nozzles 20 included in the black ink nozzle row 20K are capable of ejecting black ink. Black ink is black ink. The black ink is supplied to the print head 18 from an ink tank or ink cartridge (not shown). The black ink supplied to the print head 18 is ejected by the ink nozzles 20 included in the black ink nozzle row 20K.

[0030] The print head 18 shown in FIG. 3 is capable of ejecting six types of ink, but is not limited to this. The print head 18 may be configured to eject five or fewer types of ink, or seven or more types of ink. The print head 18 may be configured to eject two or more types of ink. The number of ink nozzles 20 included in each nozzle row shown in FIG. 3 is 14, but is not limited to this. The number of ink nozzles 20 included in each nozzle row may be fewer or more than 14. The number of ink nozzles 20 included in each nozzle row can be set as appropriate. The print head 18 shown in FIG. 3 is arranged in the following order with respect to the movement direction MD: magenta ink nozzle row 20M, light magenta ink nozzle row 20LM, cyan ink nozzle row 20C, light cyan ink nozzle row 20LC, yellow ink nozzle row 20Y, and black ink nozzle row 20K, but is not limited to this order. The arrangement order of the nozzle rows can be changed as appropriate.

[0031] Magenta, light magenta, cyan, light cyan, yellow, and black are examples of ink colors, and are not limited to these. Any two of magenta, light magenta, cyan, light cyan, yellow, and black correspond to examples of the first color and the second color.

[0032] Fig. 4 shows the block configuration of the printing device 10. The printing device 10 includes a control unit 30, a display unit 40, a communication interface 50, a transport mechanism 60, a print drive mechanism 70, a print head drive mechanism 80, and a detection mechanism 90. In Fig. 4, the interface is represented as I / F.

[0033] The control unit 30 is a controller that controls each part of the printing device 10. The control unit 30 has a control processor such as a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), etc. The control unit 30 operates as a functional part by executing a program on the control processor. The RAM and ROM function as a work area. The control unit 30 corresponds to an example of a processor.

[0034] The control unit 30 includes a storage unit 37. The storage unit 37 stores various programs, such as a print control program, and various data that run on the control unit 30. The storage unit 37 stores test pattern data and correction data, which will be described later, as data. RAM and ROM may operate as the storage unit 37, or the storage unit 37 may include a magnetic storage device such as an HDD (Hard Disk Drive), a semiconductor memory, or the like.

[0035] The control unit 30 executes a print control program to function as a print control unit 31, a read control unit 33, and a data processing unit 35. The print control unit 31, the read control unit 33, and the data processing unit 35 are functional units.

[0036] The print control unit 31 controls the print drive mechanism 70 and the print head drive mechanism 80. By controlling the print drive mechanism 70 and the print head drive mechanism 80, the print control unit 31 is able to control the print mechanism 16. The print control unit 31 causes the print mechanism 16 to print an image on the print medium M. The print control unit 31 acquires print data. The print data is stored in the memory unit 37. Alternatively, the print data is acquired from an external device via the communication interface 50. The print control unit 31 controls the print drive mechanism 70 and the print head drive mechanism 80 based on the print data, thereby causing the image to be printed on the print medium M.

[0037] The reading control unit 33 controls various sensors such as the reading sensor 15 included in the detection mechanism 90. The reading control unit 33 controls the reading sensor 15 to read an image printed on the print medium M. The image to be read is a test pattern image 100 or the like. The reading control unit 33 receives read data read by the reading sensor 15 from the reading sensor 15. The received read data is sent to the data processing unit 35.

[0038] The data processing unit 35 analyzes various data based on the data generated by the detection mechanism 90. The data processing unit 35 receives read data read by the reading sensor 15 and analyzes the read data. When the received read data is read data obtained by reading the test pattern image 100, the data processing unit 35 analyzes the read data to identify the image position within the test pattern image 100, generate correction data, determine defective nozzles, and so on. The data processing unit 35 corresponds to an example of an analysis unit. The read data corresponds to an example of a reading result.

[0039] The display unit 40 displays various information based on the control of the control unit 30. The display unit 40 includes a display. The display is configured with a liquid crystal display, an organic EL (Electro-Luminescence) display, or the like. The display may have a touch input function. The display unit 40 displays a setting screen for setting various settings such as printing conditions, an instruction screen for instructing printing, and the like.

[0040] The communication interface 50 is connected to an external device (not shown) for communication. The communication interface 50 connects to the external device via wire or wirelessly in accordance with a predetermined communication protocol. The communication interface 50 receives print data, print settings, programs, etc. from the external device. The communication interface 50 transmits print results and maintenance data, etc. from the printing device 10 to the external device.

[0041] The transport mechanism 60 transports the print medium M in the transport direction TD or the direction opposite to the transport direction TD. The transport mechanism 60 includes a feed spindle 11, a feed roller pair 13, a transport roller pair 25, and a take-up spindle 27. The transport mechanism 60 transports the print medium M based on the control of the print control unit 31 or the read control unit 33. When the printing device 10 prints on the print medium M, the transport mechanism 60 transports the print medium M in the transport direction TD based on the control of the print control unit 31. When the reading sensor 15 reads the test pattern image 100 printed on the print medium M, the transport mechanism 60 transports the print medium M in the direction opposite to the transport direction TD based on the control of the read control unit 33.

[0042] The print drive mechanism 70 drives the print mechanism 16. The print drive mechanism 70 includes a carriage 17, a carriage drive mechanism, and a carriage support shaft 19. The print drive mechanism 70 moves the carriage 17 in the movement direction MD. As the carriage 17 moves in the movement direction MD, the multiple ink nozzles 20 included in the print head 18 scan the print medium M. The print mechanism 16 scans the multiple ink nozzles 20 using the carriage 17. The scanning ink nozzles 20 form an image on the print medium M by ejecting ink. If the print mechanism 16 is a line head type, the print drive mechanism 70 may operate as a correction mechanism that corrects meandering of the print medium M.

[0043] The print head drive mechanism 80 controls the ejection of ink from the ink nozzles 20 based on the control of the print control unit 31. The print head drive mechanism 80 includes drive elements such as piezoelectric elements arranged in the print head 18. Each ink nozzle 20 ejects ink when driven by the print head drive mechanism 80. The print head drive mechanism 80 drives the multiple ink nozzles 20 to print on the print medium M. The print head drive mechanism 80 prints a test pattern image 100 on the print medium M by driving the multiple ink nozzles 20.

[0044] The detection mechanism 90 detects various operations of the printing device 10 and the presence or absence of the print medium M. The detection mechanism 90 includes a reading sensor 15, a paper detection sensor, an ink remaining amount sensor, and the like, which are not shown. The detection mechanism 90 is driven based on the control of the control unit 30. The reading sensor 15 reads the image printed on the print medium M based on instructions from the reading control unit 33 in the control unit 30. The reading operation by the reading sensor 15 corresponds to the detection operation. The detection mechanism 90 transmits detection data generated by the various sensors to the control unit 30. The reading sensor 15 transmits the read data to the control unit 30.

[0045] FIG. 5 shows an outline of a test pattern image 100 printed on a printing medium M. The test pattern image 100 shown in FIG. 5 is printed when inspecting for ejection defects in the ink nozzles 20. The test pattern image 100 shown in FIG. 5 corresponds to an example of an inspection image. The test pattern image 100 in FIG. 5 is shown in a simplified manner with some of the image omitted.

[0046] The test pattern image 100 is printed based on test pattern data stored in the storage unit 37. The test pattern data is print data that is stored in advance in the storage unit 37. The test pattern data includes information such as the shape and size of each image included in the test pattern image 100 to be printed, and the relative position between each image. The test pattern data may also include color data for each image. The printing device 10 reads out the test pattern data stored in the storage unit 37. The printing device 10 prints the test pattern image 100 on the printing medium M based on the read test pattern data.

[0047] The test pattern image 100 includes a mark image 110 and a pattern image 120. The mark image 110 shown in FIG. 5 is composed of multiple circle images of a predetermined size. The mark image 110 is used when the printing device 10 identifies a printing position on the printing medium M. The pattern image 120 is a pattern composed of multiple line images 122. The multiple line images 122 are arranged in a staircase pattern. Each of the multiple line images 122 is printed by one ink nozzle 20. The pattern image 120 is used when the printing device 10 determines whether the ink nozzle 20 is ejecting properly. The pattern image 120 corresponds to an example of a test pattern.

[0048] The mark image 110 shown in FIG. 5 is composed of a first mark 110A, a second mark 110B, a third mark 110C, a fourth mark 110D, a fifth mark 110E, a sixth mark 110F, a seventh mark 110G, and an eighth mark 110H. The first mark 110A, the third mark 110C, the fifth mark 110E, and the seventh mark 110G are arranged in a direction parallel to the Y-axis at positions in the -X direction of the pattern image 120. The second mark 110B, the fourth mark 110D, the sixth mark 110F, and the eighth mark 110H are arranged in a direction parallel to the Y-axis at positions in the +X direction of the pattern image 120. The multiple circular images constituting the mark image 110 shown in FIG. 5 are printed in positions along the X-axis, sandwiching the pattern image 120. The position of each circular image and the number of each circular image can be changed as appropriate.

[0049] The mark image 110 shown in FIG. 5 is composed of eight marks, which are circular images, but is not limited to this. The number of marks constituting the mark image 110 may be two or more, and may be different from eight. The marks shown in FIG. 5 are all the same circular shape, but are not limited to this. As long as the printing position of each image printed on the printing medium M can be identified, the shapes of the multiple marks may be the same or different. It is preferable that the shapes of the multiple marks are the same. When the shapes of the multiple marks are the same, it becomes easier to identify the printing position of each image printed on the printing medium M.

[0050] The mark image 110 shown in Fig. 5 is printed by the black ink nozzle row 20K. The color of the mark image 110 shown in Fig. 5 is black. The color of the mark image 110 is not limited to black. The color of the mark image 110 can be set as appropriate.

[0051] The pattern image 120 shown in FIG. 5 includes a first pattern 120A, a second pattern 120B, a third pattern 120C, a fourth pattern 120D, a fifth pattern 120E, and a sixth pattern 120F. The first pattern 120A, the second pattern 120B, the third pattern 120C, the fourth pattern 120D, the fifth pattern 120E, and the sixth pattern 120F are printed sequentially along the +X direction. The first pattern 120A is printed at a position in the +X direction adjacent to the first mark 110A, the third mark 110C, the fifth mark 110E, and the seventh mark 110G. Within the test pattern image 100, the first pattern 120A is disposed at a position in the +X direction adjacent to the first mark 110A, the third mark 110C, the fifth mark 110E, and the seventh mark 110G. The sixth pattern 120F is printed at a position in the -X direction adjacent to the second mark 110B, the fourth mark 110D, the sixth mark 110F, and the eighth mark 110H. Within the test pattern image 100, the sixth pattern 120F is arranged at a position in the -X direction adjacent to the second mark 110B, the fourth mark 110D, the sixth mark 110F, and the eighth mark 110H.

[0052] The first pattern 120A, second pattern 120B, third pattern 120C, fourth pattern 120D, fifth pattern 120E, and sixth pattern 120F are each printed by a different nozzle row. The first pattern 120A shown in FIG. 5 is printed by the magenta ink nozzle row 20M. The first pattern 120A is a magenta pattern. The second pattern 120B shown in FIG. 5 is printed by the light magenta ink nozzle row 20LM. The second pattern 120B is a light magenta pattern. The third pattern 120C shown in FIG. 5 is printed by the cyan ink nozzle row 20C. The third pattern 120C is a cyan pattern. The fourth pattern 120D shown in FIG. 5 is printed by the light cyan ink nozzle row 20LC. The fourth pattern 120D is a light cyan pattern. The fifth pattern 120E shown in FIG. 5 is printed by the yellow ink nozzle row 20Y. The fifth pattern 120E is a yellow pattern. The sixth pattern 120F shown in FIG. 5 is printed by the black ink nozzle row 20K. The sixth pattern 120F is a black pattern. The pattern image 120 is printed by all nozzle rows. Each pattern is printed by all ink nozzles 20 included in each nozzle row.

[0053] The first pattern 120A, the second pattern 120B, the third pattern 120C, the fourth pattern 120D, the fifth pattern 120E, and the sixth pattern 120F may be printed in colors different from those described above. The color of each pattern can be set as appropriate.

[0054] FIG. 6 is an enlarged view of the test pattern image 100 including a first mark 110A. FIG. 6 shows the first mark 110A and a first pattern 120A adjacent to the first mark 110A. The first mark 110A corresponds to an example of a first position detection mark. FIG. 6 also shows a first measurement area 130A. The first measurement area 130A is one of multiple measurement areas 130. The measurement area 130 indicates the range measured when the data processing unit 35 identifies the positions of each of the multiple marks included in the test pattern image 100. The color of the first mark 110A shown in FIG. 6 is black. Black corresponds to an example of a first color. The first pattern 120A shown in FIG. 6 is composed of multiple line images 122. The color of the first pattern 120A shown in FIG. 6 is magenta. Magenta corresponds to an example of a second color. The first pattern 120A corresponds to an example of a second-color test pattern.

[0055] The data processing unit 35 identifies the position of each mark within the read data read by the reading sensor 15. The data processing unit 35 defines a range of a predetermined size within the read data as a measurement area 130 and calculates the density distribution within the measurement area 130. The printing start position of the test pattern image 100 is controlled by the print control unit 31. The reading start position by the reading sensor 15 is controlled by the reading control unit 33. However, the print medium M may not be transported to the expected position due to meandering or slippage of the feed roller pair 13. The data processing unit 35 identifies the position of each mark within the measurement area 130 of a predetermined size by, for example, calculating the density distribution.

[0056] 6 indicates the range in which the concentration distribution of the first mark 110A is measured. The first measurement region 130A has a first measurement region width 130AW in the direction parallel to the X axis and a first measurement region length 130AL in the direction parallel to the Y axis. The first measurement region 130A corresponds to an example of a first region.

[0057] FIG. 7 shows the concentration distribution in the first measurement region 130A. FIG. 7 shows the concentration distribution on the first virtual line VL1 shown in FIG. 6. The first virtual line VL1 is a virtual line parallel to the X-axis. The data processing unit 35 measures the concentration distribution in the first measurement region 130A, including the concentration distribution on the first virtual line VL1. FIG. 7 shows a first mark concentration distribution 160A corresponding to the first mark 110A and a first pattern concentration distribution 170A corresponding to the first pattern 120A.

[0058] As an example, the data processing unit 35 determines the position of the first mark 110A by determining the concentration centroid within the first measurement region 130A. The position of the first mark 110A corresponds to an example of the first position of the first position detection mark. As shown in FIG. 6, the first pattern 120A is included within the first measurement region 130A. As shown in FIG. 7, the first pattern concentration distribution 170A is included within the first measurement region width 130AW.

[0059] FIG. 7 shows a hypothetical first pattern density distribution 170AK. The hypothetical first pattern density distribution 170AK is the output value when the first pattern 120A is printed using the black ink nozzle row 20K. The color of the first pattern 120A is black. When the color of the first pattern 120A is black, the density center of gravity of the first measurement region 130A is the hypothetical center of gravity position P1A, as shown in FIG. 7.

[0060] Because the color of the first pattern 120A is magenta, the first pattern density distribution 170A is smaller than the virtual first pattern density distribution 170AK. The density center of gravity of the first measurement region 130A is the first mark center of gravity position P1, as shown in FIG. 7. The first mark center of gravity position P1 corresponds to the first position of the first position detection mark. The color of the first mark 110A and the color of the first pattern 120A adjacent to the first mark 110A are different. Because the first mark center of gravity position P1 is less affected by the first pattern density distribution 170A, the data processing unit 35 can more accurately identify the position of the first mark 110A. Furthermore, because the influence of the first pattern density distribution 170A is less, the data processing unit 35 can set a wider first measurement region 130A. When the first measurement region 130A is wider, the data processing unit 35 can more reliably identify the position of the first mark 110A.

[0061] The data processing unit 35 analyzes the density distribution of the first mark 110A using the red channel included in the read data. Because the red channel is light reception data when the light-emitting unit emits red light, the magenta first pattern 120A reflects a large amount of red light, while the black first mark 110A absorbs the light. Therefore, if the data processing unit 35 estimates the density distribution based on the reflected light printed on, for example, a white printing medium M, the output value of the density distribution of the black first mark 110A will be high. In other words, the reflected light from the white printing medium M, which also reflects red light, will be confused with the reflected light from the magenta first pattern A, resulting in a low output value of the density distribution of the first pattern A. In other words, by using the red channel for analysis, the data processing unit 35 further reduces the output value of the first pattern density distribution 170A. Red corresponds to an example of a color related to magenta. The data processing unit 35 can suppress the influence of the magenta first pattern 120A adjacent to the first mark 110A. The red channel corresponds to an example of the first channel that extracts a color related to the first color. For ease of understanding, a white print medium M is shown as an example, but based on the above-mentioned concept, the reading sensor 15 only needs to read in a color channel where the gap between the reflected light of the first mark 110A and the reflected light of the first pattern 120A is large, so the color of the print medium is not limited to white.

[0062] When analyzing the magenta first pattern 120A, the data processing unit 35 uses a green channel that extracts the green component. By using the green channel, the data processing unit 35 can suppress the influence of the second pattern 120B adjacent to the first pattern 120A, and perform a highly accurate analysis. Green corresponds to an example of a color different from the color related to the second color. The green channel corresponds to a color different from the color related to the second color as an example of the second channel.

[0063] The read data has a red channel from which red is extracted. Preferably, the data processing unit 35 analyzes the first mark 110A using the red channel. The read data also has a green channel from which green, which is different from red, is extracted. Preferably, the data processing unit 35 analyzes the magenta first pattern 120A using the green channel. The printing device 10 can reduce the influence of the color of the first pattern 120A when specifying the position of the first mark 110A.

[0064] The color of the first mark 110A is not limited to black. The color of the first pattern 120A is not limited to magenta. For example, the color of the first mark 110A may be printed in magenta. The first pattern 120A may be printed in cyan. The data processing unit 35 analyzes the first mark 110A using a green channel and analyzes the first pattern 120A using a red channel. It is preferable that the data processing unit 35 appropriately selects the red channel, green channel, and blue channel depending on the color of the mark or pattern to be analyzed.

[0065] When the data processing unit 35 performs analysis using the red, green, and blue channels, it is preferable that the colors of each pattern included in the test pattern image 100 are adjusted in advance. For example, if the first pattern 120A is magenta, it is preferable that the second pattern 120B is cyan. Cyan corresponds to an example of a third color. It is preferable that the color of the second pattern 120B adjacent to the first pattern 120A is close to the complementary color of the first pattern 120A. The person designing the test pattern image 100 sets the color of the second pattern 120B adjacent to the first pattern 120A to a color close to the complementary color in advance. By using the green channel when analyzing the first pattern 120A, the data processing unit 35 can perform analysis that suppresses the influence of the cyan second pattern 120B.

[0066] 6 and 7 show that the first mark density distribution 160A is determined in the first measurement region 130A, but this is not limiting. The density distribution of any one of the second mark 110B, the third mark 110C, the fourth mark 110D, the fifth mark 110E, the sixth mark 110F, the seventh mark 110G, and the eighth mark 110H is measured in the first measurement region 130A.

[0067] FIG. 8 is an enlarged view of the test pattern image 100 including the second mark 110B. FIG. 8 shows the second mark 110B and a sixth pattern 120F adjacent to the second mark 110B. The second mark 110B corresponds to an example of a second position detection mark. FIG. 8 also shows the second measurement region 130B. The second measurement region 130B is one of the multiple measurement regions 130. The second mark 110B shown in FIG. 8 is black in color. The sixth pattern 120F shown in FIG. 8 is composed of multiple line images 122. The sixth pattern 120F shown in FIG. 8 is black in color.

[0068] 8 indicates the range in which the concentration distribution of the second mark 110B is measured. The second measurement region 130B has a second measurement region width 130BW in the direction parallel to the X axis and a second measurement region length 130BL in the direction parallel to the Y axis. The second measurement region 130B corresponds to an example of a second region.

[0069] The second measurement region 130B is narrower than the first measurement region 130A. The second measurement region width 130BW shown in FIG. 8 is shorter than the first measurement region width 130AW. The second measurement region length 130BL shown in FIG. 8 is shorter than the first measurement region length 130AL. The area of ​​the second measurement region 130B is smaller than the area of ​​the first measurement region 130A.

[0070] The memory unit 37 stores test pattern data in advance. The test pattern data includes information on the relative positions of each mark and each pattern. By identifying the position of the first mark 110A, the data processing unit 35 can estimate the position of the second mark 110B with high accuracy. The data processing unit 35 can identify the position of the second mark 110B in the second measurement area 130B, which is smaller than the first measurement area 130A. The position of the second mark 110B corresponds to an example of the second position of the second position detection mark.

[0071] FIG. 9 shows the concentration distribution in the second measurement region 130B. FIG. 9 shows the concentration distribution on the second virtual line VL2 shown in FIG. 8. The second virtual line VL2 is a virtual line parallel to the X-axis. The data processing unit 35 measures the concentration distribution in the second measurement region 130B, including the concentration distribution on the second virtual line VL2. FIG. 9 shows a second mark concentration distribution 160B corresponding to the second mark 110B and a sixth pattern concentration distribution 170F corresponding to the sixth pattern 120F.

[0072] As an example, the data processing unit 35 determines the position of the second mark 110B by determining the concentration centroid within the second measurement region 130B. As shown in FIG. 8, the sixth pattern 120F is not included within the second measurement region 130B. As shown in FIG. 9, the sixth pattern concentration distribution 170F is not included within the second measurement region width 130BW. The data processing unit 35 can accurately determine the second mark centroid position P2.

[0073] Because the second measurement area 130B is narrower than the first measurement area 130A, the data processing unit 35 is less affected by the sixth pattern 120F adjacent to the second mark 110B. In addition, the person setting the test pattern image 100 can set the color of the sixth pattern 120F adjacent to the second mark 110B to black.

[0074] 8 and 9 show that second mark density distribution 160B is determined in second measurement region 130B, but this is not limiting. When the position of first mark 110A is determined in first measurement region 130A, the positions of third mark 110C, fourth mark 110D, fifth mark 110E, sixth mark 110F, seventh mark 110G, and eighth mark 110H may be determined in a measurement region 130 that is the same size as second measurement region 130B.

[0075] As described above, the printing device 10 includes a printing mechanism 16 that prints a test pattern image 100, a reading sensor 15 that reads the test pattern image 100 printed by the printing mechanism 16, and a data processing unit 35 that analyzes the data read by the reading sensor 15. The test pattern image 100 has a multi-color pattern image 120 including a first mark 110A printed in black, a second mark 110B printed in black, and a first pattern 120A printed in magenta, a color different from black. The printing mechanism 16 prints the first pattern 120A in a position adjacent to the first mark 110A. The data processing unit 35 determines the position of the first mark 110A in a first measurement area 130A. The data processing unit 35 determines the position of the second mark 110B in a second measurement area 130B, which is narrower than the first measurement area 130A. The printing device 10 can reduce the influence of the first pattern 120A when specifying the position of the first mark 110A. Furthermore, the printing device 10 can reduce the influence of the sixth pattern 120F when specifying the position of the second mark 110B. The printing device 10 can accurately specify the positions of the first mark 110A and the second mark 110B.

[0076] 6 and 8 show circular images of a predetermined size as the first mark 110A and the second mark 110B. The shapes of the first mark 110A and the second mark 110B are not limited to circular images. The shapes of the first mark 110A and the second mark 110B may be marks of a predetermined shape, such as a register mark formed by two intersecting lines. The data processing unit 35 estimates the shape of the mark according to the output value of the read data. The data processing unit 35 may identify the position of the mark based on the estimated shape of the mark.

[0077] The data processing unit 35 preferably determines the positions of the first mark 110A and the second mark 110B by determining the density distribution of the marks. The data processing unit 35 can easily determine the positions of the first mark 110A and the second mark 110B. By having the data processing unit 35 determine the positions of the marks from the density distribution of the marks, the person setting the test pattern image 100 can use a circular image as the mark image 110. When the mark image 110 is tilted during printing, the data processing unit 35 is less susceptible to the influence of the tilt.

[0078] The data processing unit 35 of the printing device 10 determines the position of the first mark 110A based on the density distribution of black in the first measurement area 130A, and determines the position of the second mark 110B based on the density distribution of black in the second measurement area 130B. The printing device 10 specifies the positions of the first marks 110A and the second marks 110B based on the density distribution, and therefore can specify the positions with high accuracy.

[0079] 5 is printed in the following order parallel to the X-axis: first mark 110A, first pattern 120A, second pattern 120B, third pattern 120C, fourth pattern 120D, fifth pattern 120E, sixth pattern 120F, and second mark 110B. The first mark 110A and the second mark 110B are printed parallel to the X-axis with the pattern image 120 sandwiched between them. Positioning the first mark 110A and the second mark 110B with the pattern image 120 sandwiched between them improves the accuracy of identifying the positions of the images forming the pattern image 120.

[0080] The printing mechanism 16 of the printing device 10 prints the pattern image 120 between the first mark 110A and the second mark 110B in the direction parallel to the X axis.

[0081] Fig. 10 shows a flowchart of image processing performed by the printing device 10. The image processing method shown in Fig. 10 is performed by the control unit 30 executing a print control program. The print control program corresponds to an example of an image processing program.

[0082] In step S101, the printing device 10 prints a test pattern image 100. The printing device 10 prints the test pattern image 100 based on the test pattern data stored in the storage unit 37. As shown in FIG. 5, the test pattern image 100 has a first mark 110A, a second mark 110B, and a pattern image 120. The first mark 110A is printed by the black ink nozzle row 20K. The first mark 110A is black. The second mark 110B is printed by the black ink nozzle row 20K. The second mark 110B is black.

[0083] The test pattern image 100 has a third mark 110C, a fourth mark 110D, a fifth mark 110E, a sixth mark 110F, a seventh mark 110G, and an eighth mark 110H. The third mark 110C, the fourth mark 110D, the fifth mark 110E, the sixth mark 110F, the seventh mark 110G, and the eighth mark 110H are printed by the black ink nozzle row 20K. The third mark 110C, the fourth mark 110D, the fifth mark 110E, the sixth mark 110F, the seventh mark 110G, and the eighth mark 110H are black.

[0084] The pattern image 120 includes a first pattern 120A, a second pattern 120B, a third pattern 120C, a fourth pattern 120D, a fifth pattern 120E, and a sixth pattern 120F. The first pattern 120A is printed by the magenta ink nozzle row 20M. The first pattern 120A is a magenta pattern. The second pattern 120B is printed by the light magenta ink nozzle row 20LM. The second pattern 120B is a light magenta pattern. The third pattern 120C is printed by the cyan ink nozzle row 20C. The third pattern 120C is a cyan pattern. The fourth pattern 120D is printed by the light cyan ink nozzle row 20LC. The fourth pattern 120D is a light cyan pattern. The fifth pattern 120E is printed by the yellow ink nozzle row 20Y. The fifth pattern 120E is a yellow pattern. The sixth pattern 120F is printed by the black ink nozzle row 20K. The sixth pattern 120F is a black pattern.

[0085] The first pattern 120A is arranged adjacent to the first mark 110A, the third mark 110C, the fifth mark 110E, and the seventh mark 110G. The sixth pattern 120F is arranged adjacent to the second mark 110B, the fourth mark 110D, the sixth mark 110F, and the eighth mark 110H.

[0086] After printing the test pattern image 100, the printing device 10 reads the test pattern image 100 using the reading sensor 15 in step S103. The reading sensor 15 reads the test pattern image 100 and generates read data. The read data includes a red channel, a green channel, and a blue channel. The data processing unit 35 acquires the read data generated by the reading sensor 15.

[0087] After acquiring the read data, the printing device 10 determines the position of the first mark 110A in step S105. The position of the first mark 110A is the printing position on the printing medium M. The data processing unit 35 estimates the position of the first mark 110A based on print control data used by the print control unit 31. The print control data is control data generated based on test pattern data, which is print data. The data processing unit 35 measures the black density distribution within the first measurement area 130A that includes the estimated position. As shown in FIG. 6, the first measurement area 130A has a first measurement area width 130AW and a first measurement area length 130AL. The data processing unit 35 calculates the density center of gravity of the black density distribution. By calculating the density center of gravity, the data processing unit 35 determines the position of the first mark 110A.

[0088] After determining the position of the first mark 110A, the printing device 10 determines the position of the second mark 110B in step S107. The position of the second mark 110B is the printing position on the printing medium M. The data processing unit 35 estimates the position of the second mark 110B based on the determined position of the first mark 110A. The data processing unit 35 measures the black density distribution within a second measurement area 130B that includes the estimated position. As shown in FIG. 8, the second measurement area 130B has a second measurement area width 130BW and a second measurement area length 130BL. The second measurement area 130B is narrower than the first measurement area 130A. Because the position of the second mark 110B is estimated based on the determined position of the first mark 110A, the estimated position of the second mark 110B is estimated with high accuracy. Even if the second measurement area 130B is narrower than the first measurement area 130A, the data processing unit 35 can identify the position of the second mark 110B. The data processing unit 35 calculates the density centroid of the black density distribution. By calculating the density centroid, the data processing unit 35 identifies the position of the second mark 110B.

[0089] The position of the first mark 110A is identified based on the density distribution of black in the first measurement region 130A, and the position of the second mark 110B is identified based on the density distribution of black in the second measurement region 130B. The printing device 10 specifies the positions of the first marks 110A and the second marks 110B based on the density distribution, and therefore can specify the positions with high accuracy.

[0090] The printing device 10 may identify the position of the third mark 110C. FIG. 11 is an enlarged view of the test pattern image 100 including the third mark 110C. FIG. 11 shows the third mark 110C and a first pattern 120A adjacent to the third mark 110C. The first pattern 120A is composed of a plurality of line images 122. The third mark 110C corresponds to an example of a third position detection mark. The position of the third mark 110C corresponds to an example of a third position of the third position detection mark. The position of the third mark 110C is a printing position on the printing medium M. The data processing unit 35 estimates the position of the third mark 110C based on the identified position of the first mark 110A. The data processing unit 35 measures the black density distribution within a third measurement region 130C that includes the estimated position. As shown in FIG. 11, the third measurement region 130C has a third measurement region width 130CW and a third measurement region length 130CL. The third measurement region 130C corresponds to an example of a third region. The third measurement region 130C may be the same size as the second measurement region 130B. The third measurement region width 130CW may be the same as the second measurement region width 130BW. The third measurement region length 130CL may be the same as the second measurement region length 130BL. The third measurement region 130C is narrower than the first measurement region 130A. Since the position of the third mark 110C is estimated based on the identified position of the first mark 110A, the estimated position of the third mark 110C is estimated with high accuracy. Even if the third measurement region 130C is narrower than the first measurement region 130A, the data processing unit 35 can identify the position of the third mark 110C. The data processing unit 35 calculates the density centroid of the black density distribution. The data processing unit 35 identifies the position of the third mark 110C by calculating the density centroid.

[0091] The printing device 10 identifies the positions of the fourth mark 110D, the fifth mark 110E, the sixth mark 110F, the seventh mark 110G, and the eighth mark 110H, as well as the third mark 110C.

[0092] The printed test pattern image 100 has a first mark 110A and a third mark 110C that is different from the second mark 110B. The printing device 10 determines the position of the third mark 110C in the third measurement area 130C that is narrower than the first measurement area 130A. It is preferable that the printing device 10 determines the position of the third mark 110C in the third measurement area 130C that is the same size as the second measurement area 130B. The printing device 10 can detect the position of the third mark 110C while suppressing the influence of the first pattern 120A adjacent to the third mark 110C.

[0093] After identifying the position of the second mark 110B, the printing device 10 performs a faulty nozzle determination in step S109. The data processing unit 35 identifies the position of each line image 122 in the pattern image 120 based on the identified positions of the first mark 110A and the second mark 110B. The data processing unit 35 compares the identified position of each line image 122 with a reference position of each line image 122 estimated in advance. The data processing unit 35 performs a faulty nozzle determination based on the difference between the identified position of each line image 122 and the reference position of each line image 122 estimated in advance. The data processing unit 35 identifies the position of each line image 122 based on the first mark 110A and the second mark 110B. The data processing unit 35 can identify the position of each line image 122 with high accuracy. The printing device 10 can determine not only whether the ink nozzle 20 is ejecting ink, but also whether the ink ejected from the ink nozzle 20 is deflecting.

[0094] A test pattern image 100 having a multi-color pattern image 120 including a first mark 110A formed in black, a second mark 110B formed in black, and a first pattern 120A formed in magenta, which is a color different from black, is printed with the first pattern 120A positioned adjacent to the first mark 110A, the test pattern image 100 is read to obtain read data, the position of the first mark 110A is identified in a first measurement area 130A, and the position of the second mark 110B is identified in a second measurement area 130B narrower than the first measurement area 130A. The printing device 10 can reduce the influence of the color of the first pattern 120A when specifying the position of the first mark 110A. Furthermore, the printing device 10 can reduce the influence of the sixth pattern 120F when specifying the position of the second mark 110B. The printing device 10 can accurately specify the positions of the first mark 110A and the second mark 110B.

[0095] A printing control program executed by a control unit (30) of a printing device (10) that prints a test pattern image (100) includes a test pattern image (100) having a pattern image (120) of multiple colors including a first mark (110A) formed in black, a second mark (110B) also formed in black, and a first pattern (120A) formed in magenta, a color different from black, with the first pattern (120A) positioned adjacent to the first mark (110A), reads the test pattern image (100) to obtain read data, identifies the position of the first mark (110A) in a first measurement area (130A), and identifies the position of the second mark (110B) in a second measurement area (130B) that is narrower than the first measurement area (130A) of the read data. The printing device 10 can reduce the influence of the color of the first pattern 120A when specifying the position of the first mark 110A. Furthermore, the printing device 10 can reduce the influence of the sixth pattern 120F when specifying the position of the second mark 110B. The printing device 10 can accurately specify the positions of the first mark 110A and the second mark 110B.

[0096] The pattern image 120 is not limited to the stepped pattern shown in Fig. 5. The form of the pattern image 120 can be changed as appropriate as long as it is an image used to evaluate the printing device 10, such as a patch image for evaluating color gradation. In this case, it is sufficient that the image adjacent to the mark image 110 is an image of a different color from the mark image 110.

[0097] In this specification, "adjacent" does not necessarily mean adjacent positions. Also, it is not necessarily limited to the mark image 110 and the image used for evaluation being adjacent in the X direction as shown in the figure. If the mark image 110 and the image used for evaluation are close to each other to a certain extent and the detection accuracy of the mark image 110 is reduced due to the influence of their positional relationship or color, they can be considered adjacent. [Explanation of symbols]

[0098] 10...printing device, 11...feed shaft, 13...feed roller pair, 13A...first feed roller, 13B...second feed roller, 15...reading sensor, 16...printing mechanism, 17...carriage, 18...print head, 19...carriage support shaft, 20...ink nozzle, 20C...cyan ink nozzle row, 20LC...light cyan ink nozzle row, 20M...magenta ink nozzle row, 20LM...light magenta ink nozzle row, 20Y...yellow ink nozzle row, 20K...black ink nozzle row, 25...transport roller pair, 25A ...First transport roller, 25B...Second transport roller, 27...Winding shaft, 30...Control unit, 31...Printing control unit, 33...Reading control unit, 35...Data processing unit, 37...Memory unit, 40...Display unit, 50...Communication interface, 60...Transport mechanism, 70...Printing drive mechanism, 80...Print head drive mechanism, 90...Detection mechanism, 95...First side plate, 97...Second side plate, 100...Test pattern image, 110...Mark image, 110A...First mark, 110B...Second mark, 110C...Third mark, 110D...Fourth mark, 110E ...5th mark, 110F...6th mark, 110G...7th mark, 110H...8th mark, 120...pattern image, 120A...1st pattern, 120B...2nd pattern, 120C...3rd pattern, 120D...4th pattern, 120E...5th pattern, 120F...6th pattern, 122...line image, 130...measurement area, 130A...first measurement area, 130AL...first measurement area length, 130AW...first measurement area width, 130B...second measurement area, 130BL...second measurement area length, 130BW...second measurement area width, 130C ...third measurement area, 130CL...third measurement area length, 130CW...third measurement area width, 160A...first mark density distribution, 160B...second mark density distribution, 170A...first pattern density distribution, 170F...sixth pattern density distribution, 170AK...virtual first pattern density distribution, M...printing medium, MD...movement direction, P1...first mark center of gravity position, P1A...virtual center of gravity position, P2...second mark center of gravity position, PD...nozzle arrangement direction, R1...medium roll, R2...take-up roll, TD...conveyance direction, VL1...first virtual line, VL2...second virtual line.

Claims

1. a printing unit that prints the inspection image; a reading unit that reads the inspection image printed by the printing unit; an analysis unit that analyzes the result of reading by the reading unit, The inspection image is a first position detection mark printed in a first color; and a second position detection mark printed in the first color. and a multi-color test pattern including a second color test pattern printed in a second color different from the first color. Has a turn, The printing unit printing the second color test pattern at a position adjacent to the first position detection mark; The analysis unit When the first measurement area includes the first position detection mark and the second color test pattern, In the first measurement area, the first position detection is performed using color channels corresponding to the colors of the multi-color test pattern. Identify the first position of the exit mark, The second measurement area is narrower than the first measurement area and includes the second position detection mark but does not include the second color test pattern. a second measurement area that does not include a mark, and a second position of the second position detection mark is identified in the second measurement area; do, Liquid discharge device.

2. The printing unit is configured to print the first position detection mark and the second position detection mark in a predetermined direction. and printing the test pattern so that it is positioned between the mark and the test pattern. The liquid ejection device according to claim 1 .

3. The analysis unit Identifying the first position based on a density distribution of the first color within the first measurement area; identifying the second position based on a density distribution of the first color within the second measurement area; The liquid ejection device according to claim 1 or 2.

4. the read result has a first channel that extracts a color related to the second color, The analysis unit analyzing the first position detection mark using the first channel; The liquid ejection device according to claim 1 .

5. the test image has a third-color test pattern printed in a third color different from the second color; the read result has a second channel in which a color different from the color related to the second color is extracted, the analysis unit analyzes the second-color test pattern using the second channel. The liquid ejection device according to claim 1 .

6. a first position detection mark formed in a first color; and a second position detection mark formed in the first color. and a plurality of color test patterns including a second color test pattern formed in a second color different from the first color. The inspection image having the turn is placed at a position adjacent to the first position detection mark by the second color inspection pattern. Place and print the turns, reading the inspection image to obtain a reading result; When the first measurement area includes the first position detection mark and the second color test pattern, In the first measurement area, the first position detection is performed using color channels corresponding to the colors of the multi-color test pattern. Identify the first position of the exit mark, The second measurement area is narrower than the first measurement area and includes the second position detection mark but does not include the second color test pattern. a second measurement area that does not include a mark, and a second position of the second position detection mark is identified in the second measurement area; do, Image processing methods.

7. The printed inspection image includes the first position detection mark and the second position detection mark. a third position detection mark that is different from the first position detection mark; A third position detection mark is detected in a third measurement area narrower than the first measurement area. Identify the location, The image processing method according to claim 6.

8. 8. The image processing method according to claim 7, wherein the second measurement area and the third measurement area are the same size. method.

9. the first position is identified based on a density distribution of the first color in the first measurement area; the second position is identified based on a density distribution of the first color in the second measurement area; The image processing method according to any one of claims 6 to 8.

10. An image processing program executed by a processor of a liquid ejection device that prints a test image. So, The image processing program includes: a first position detection mark formed in a first color; and a second position detection mark formed in the first color. and a plurality of color test patterns including a second color test pattern formed in a second color different from the first color. The inspection image having the turn is positioned adjacent to the first position detection mark by the second color detection mark. The inspection pattern is placed and printed. reading the inspection image and obtaining a reading result; When the first measurement area includes the first position detection mark and the second color test pattern, In the first measurement area, the first position detection is performed using color channels corresponding to the colors of the multi-color test pattern. Identify the first position of the exit mark, The second measurement area is narrower than the first measurement area and includes the second position detection mark but does not include the second color test pattern. a second measurement area that does not include a mark, and a second position of the second position detection mark is identified in the second measurement area; to make, Image processing program.

Images