Test pattern, printing method of test pattern, and printing device

Abstract

The inclination of the nozzle is grasped. The regions (51A, 52A) of the test pattern (50) include a baseline (530) formed in the Y direction with ink ejected from the nozzle portions (231, 241) of the nozzles (23, 24), and a block (540) and a block (550) formed with ink ejected from the nozzle portions (235, 245) of the nozzles (23, 24) disposed at an interval apart from the first nozzle portions (231, 241) in the Y direction. The block (540) is formed on the XI side in the X direction orthogonal to the Y direction of the baseline (530), and the block (550) is formed on the X2 side.

Description

Technical Field

[0001] This invention relates to test patterns, a method for printing test patterns, and a printing apparatus. Background Technology

[0002] The printing apparatus has an inkjet head that ejects ink. The inkjet head has multiple nozzle rows arranged in the main scanning direction. Each nozzle row consists of multiple nozzles arranged in the sub-scanning direction. In the printing apparatus, ink is ejected from each nozzle while the media and the inkjet head move relative to each other in the main scanning direction and the sub-scanning direction, thereby printing the media.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2021-94827 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] Inkjet heads may sometimes tilt due to tasks such as nozzle changes. Printing directly with the inkjet head tilted can sometimes negatively impact print quality. Therefore, it is desirable to control the inkjet head tilt in a printing system.

[0008] Furthermore, if the configuration of any of the multiple inkjet heads is misaligned, the ink droplet position of that inkjet head may sometimes shift from the ink droplet positions of other inkjet heads. The ink droplet position refers to the location where the ink ejected from the nozzle of the inkjet head lands on the media.

[0009] If the ink droplets from multiple inkjet heads are not positioned correctly, it can affect the quality of the printed material. Therefore, it is desirable to monitor the offset of the ink droplet positions from the inkjet heads in a printing device.

[0010] Solution for solving the problem

[0011] The present invention is,

[0012] (1) A test pattern, wherein the test pattern is printed on a medium by ejecting ink from an inkjet head having a plurality of nozzles, wherein...

[0013] The test pattern includes:

[0014] A first baseline is formed along a first direction using ink ejected from a first nozzle portion of the inkjet head; and

[0015] The first and second blocks are formed using ink ejected from a second nozzle portion of the inkjet head, which is disposed at an open interval from the first nozzle portion in the first direction.

[0016] The first block is formed on one side of the first baseline in a second direction orthogonal to the first direction, and the second block is formed on the other side of the first baseline in the second direction.

[0017] (2) In the test pattern,

[0018] Multiple first baselines are formed at open intervals in the second direction.

[0019] Multiple first blocks are arranged along the second direction, each located on one side of a plurality of first baselines.

[0020] Multiple second blocks are arranged along the second direction, each located on the other side of one of the multiple first baselines.

[0021] The plurality of said first blocks and the plurality of said second blocks are arranged in a staggered manner in the second direction without overlapping.

[0022] The set of the first blocks forms the first graphic, and the set of the second blocks forms the second graphic.

[0023] (3) In the test pattern, the inkjet head is configured to rotate about an inclined axis extending along a third direction orthogonal to the first direction and the second direction.

[0024] (4) In the test pattern, the first graphic and the second graphic are graphics with different appearances. Depending on the rotation direction of the tilt axis, either the first graphic or the second graphic is visually recognized as a graphic that is darker than the other.

[0025] (5) In the test pattern, the first pattern and the second pattern respectively contain markings indicating the rotation direction of the tilt axis.

[0026] (6) In the test pattern, the first nozzle portion and the second nozzle portion are each composed of a plurality of nozzles arranged at certain intervals along the second direction.

[0027] The nozzles of the first nozzle section and the nozzles of the second nozzle section are arranged alternately in the second direction.

[0028] The first baseline is formed by the first nozzle of the first nozzle portion.

[0029] The first block is formed by a second nozzle adjacent to the first nozzle on one side of the second nozzle portion in the second direction.

[0030] The second block is formed by a third nozzle adjacent to the first nozzle on the other side of the second nozzle portion in the second direction.

[0031] (7) In the test pattern, the first nozzle section and the second nozzle section are composed of a plurality of nozzles arranged at certain intervals along the second direction.

[0032] The nozzles of the first nozzle section and the second nozzle section are positioned at the same location in the second direction.

[0033] The first baseline is formed by the first nozzle of the first nozzle portion.

[0034] The first block is formed by a second nozzle adjacent to the first nozzle on one side of the second nozzle portion in the second direction.

[0035] The second block is formed by a third nozzle adjacent to the first nozzle on the other side of the second nozzle portion in the second direction.

[0036] (8) In the test pattern, the test pattern includes:

[0037] The second baseline is formed along the first direction using ink ejected from the third nozzle portion of the inkjet head;

[0038] The third block is formed by ink ejected from a fourth nozzle portion of the inkjet head, which is spaced apart from the third nozzle portion in the first direction. This third block is formed adjacent to the second baseline on one side of the second baseline in the second direction.

[0039] The fourth block, formed using ink ejected from the fourth nozzle, is formed adjacent to the second baseline on the other side of the second baseline in the second direction, and is disposed at a distance from the third block in the first direction.

[0040] The distance in the first direction between the third nozzle portion and the fourth nozzle portion is longer than the distance in the first direction between the first nozzle portion and the second nozzle portion.

[0041] The present invention is,

[0042] (9) A method for printing a test pattern, wherein the test pattern is printed on the medium by ejecting ink from an inkjet head having multiple nozzles, wherein...

[0043] Ink is ejected from the first nozzle portion of the inkjet head, thereby forming a first baseline along the first direction.

[0044] Ink is ejected from a second nozzle portion of the inkjet head, which is disposed at a distance from the first nozzle portion in the first direction, thereby forming the first block and the second block.

[0045] The first block is formed on one side of the first baseline in a second direction orthogonal to the first direction, and the second block is formed on the other side of the first baseline in the second direction.

[0046] The present invention is,

[0047] (10) A printing apparatus that prints a test pattern onto a medium by ejecting ink from an inkjet head having a plurality of nozzles, wherein...

[0048] Ink is ejected from the first nozzle portion of the inkjet head into the medium, thereby forming a first baseline along a first direction.

[0049] Ink is ejected from a second nozzle portion of the inkjet head, which is disposed at a distance from the first nozzle portion in the first direction, thereby forming the first block and the second block.

[0050] The first block is formed on one side of the first baseline in a second direction orthogonal to the first direction, and the second block is formed on the other side of the first baseline in the second direction.

[0051] Furthermore, the present invention is,

[0052] (1) A test pattern printed on a medium using ink ejected from a first inkjet head and a second inkjet head, wherein,

[0053] The test pattern has a first line and a second line printed alternately in the first direction.

[0054] The first line is formed by ink ejected from a plurality of nozzles arranged in a second direction orthogonal to the first direction from the first inkjet head.

[0055] The second line is formed by ink ejected from a plurality of nozzles arranged in the second direction from the second inkjet head.

[0056] (2) In the test pattern, the first line and the second line have an overlapping portion when viewed from the first direction.

[0057] When the landing position of the ink ejected from the nozzle of the first inkjet head and the landing position of the ink ejected from the nozzle of the second inkjet head are within a predetermined range in the first direction, the overlapping portion is visually identified as a filled area.

[0058] (3) In the test pattern, the test pattern also has:

[0059] The first baseline is formed using ink ejected from the nozzle of the first inkjet head; and

[0060] The second baseline is formed using ink ejected from the nozzles of the second inkjet head.

[0061] When the landing position of the ink ejected from the nozzle of the first inkjet head is consistent with the landing position of the ink ejected from the nozzle of the second inkjet head in the first direction, the first reference line and the second reference line have an overlapping area.

[0062] (4) In the test pattern, taking an imaginary line along the first direction as a reference, the test pattern also has a pattern in which a first linear portion located on the side of the imaginary line closer to the second direction and a second linear portion located on the other side of the imaginary line closer to the second direction are alternately arranged in the first direction.

[0063] The first linear portion and the second linear portion are formed by the overlap of ink ejected from the nozzle of the first inkjet head and ink ejected from the nozzle of the second inkjet head.

[0064] (5) In the test pattern, the pattern has a first region filled with ink ejected from the nozzle of the first inkjet head on one side of the imaginary line, and a second region filled with ink ejected from the nozzle of the second inkjet head on the other side of the imaginary line.

[0065] The first linear portion and the second linear portion are formed by the opposite ends of the first region and the second region.

[0066] (6) In the test pattern, if the landing position of the ink ejected from the nozzle of the first inkjet head is inconsistent with the landing position of the ink ejected from the nozzle of the second inkjet head in the second direction, a gap or a high-concentration area is generated at the boundary between the first region and the second region.

[0067] (7) In the test pattern, the first linear portion and the second linear portion are parallel to the imaginary line.

[0068] The ends of the first linear portion and the second linear portion are connected by a third linear portion orthogonal to the imaginary line.

[0069] The third linear portion is formed by the overlap of ink ejected from the nozzle of the first inkjet head and ink ejected from the nozzle of the second inkjet head.

[0070] The present invention is,

[0071] (8) A method for printing a test pattern, wherein the test pattern is printed on a medium by ejecting ink from a first inkjet head and a second inkjet head, wherein,

[0072] Print lines 1 and 2 alternately in the first direction.

[0073] The first line is formed by ejecting ink from a plurality of nozzles arranged in a second direction orthogonal to the first direction from the first inkjet head.

[0074] The second line is formed by ejecting ink from a plurality of nozzles arranged in the second direction from the second inkjet head.

[0075] The present invention is,

[0076] (9) A method for printing a test pattern, wherein the test pattern is printed on a medium by ejecting ink from a first inkjet head and a second inkjet head, wherein,

[0077] Print lines 1 and 2 alternately in the first direction.

[0078] The first line is formed by ejecting ink from a plurality of nozzles arranged in a second direction orthogonal to the first direction from the first inkjet head.

[0079] The second line is formed by ejecting ink from a plurality of nozzles arranged in the second direction from the second inkjet head.

[0080] The effects of the invention

[0081] According to the present invention, the tilt of the inkjet head can be determined based on the test pattern.

[0082] Furthermore, according to the present invention, the offset of the ink droplet position of the inkjet head can be determined based on the test pattern. Attached Figure Description

[0083] Figure 1 This is a perspective view of the printing device from the front side.

[0084] Figure 2 It is a block diagram showing the structure of the printing device.

[0085] Figure 3 This is a schematic diagram showing the nozzle as viewed from the front side.

[0086] Figure 4 This is a schematic diagram showing the nozzle as viewed from above.

[0087] Figure 5 This is a schematic diagram showing the arrangement of the nozzles that make up the nozzle section.

[0088] Figure 6 This is a diagram illustrating a printing example where the ink droplets from the printhead are aligned.

[0089] Figure 7This is a diagram illustrating a printing example where the ink droplets from the printhead are not positioned correctly.

[0090] Figure 8 This is a flowchart illustrating an example of a calibration step.

[0091] Figure 9 It is a diagram showing the test pattern used for tilt correction.

[0092] Figure 10 yes Figure 9 An enlarged view of the portion enclosed by box A.

[0093] Figure 11 It is a diagram illustrating the method of forming the test pattern.

[0094] Figure 12 This is a diagram illustrating the changes in the test pattern when the nozzle is tilted.

[0095] Figure 13 This is a diagram illustrating the changes in the test pattern when the nozzle is tilted.

[0096] Figure 14 This is a diagram illustrating the positional relationship of the nozzle section.

[0097] Figure 15 This diagram illustrates a situation where the nozzle is tilted significantly.

[0098] Figure 16 This diagram illustrates the case where the nozzle is tilted at a relatively small angle.

[0099] Figure 17 It is a diagram showing a test pattern used for position offset correction in the Y direction.

[0100] Figure 18 It is a diagram illustrating the method of forming the test pattern.

[0101] Figure 19 This is a diagram illustrating the changes in the test pattern when the nozzle has a positional offset in the Y direction.

[0102] Figure 20 It is a diagram showing a test pattern used for position offset correction in the X direction.

[0103] Figure 21 yes Figure 20 An enlarged view of the portion enclosed by box A.

[0104] Figure 22 This is a diagram illustrating the changes in the test pattern when the nozzle's position shifts in the X direction.

[0105] Figure 23 This is a diagram showing a test pattern indicating a positional offset of the nozzle in the Y direction.

[0106] Figure 24 This is a diagram illustrating the method for forming the test pattern of variation 1. Detailed Implementation

[0107] The embodiments of the present invention will be described below.

[0108] Figure 1 This is a perspective view of the printing device 1 from the front side.

[0109] Figure 2 This is a block diagram showing the structure of the printing device 1.

[0110] Figure 3 This is a schematic diagram showing the nozzle 22 as viewed from the front side.

[0111] Figure 4 This is a schematic diagram showing the nozzle 22 as viewed from above.

[0112] Furthermore, in the following explanation, "Y direction" refers to the main scanning direction (first direction) of the printing device 1. The main scanning direction is the left-right direction when viewed from the front of the printing device 1. "X direction" refers to the sub-scanning direction (second direction). The sub-scanning direction is orthogonal to the main scanning direction and is the direction from the front side of the printing device 1 to the back side. "Z direction" refers to the vertical direction when the printing device 1 is placed on a horizontal plane, and is the direction orthogonal to both the X and Y directions (third direction). In addition, "Y1 side" refers to one side in the Y direction when viewed from the front of the printing device 1. Figure 3 "Y2 side" refers to the other side (left side). Figure 3 (The right side). "X1 side" refers to the front side of the printing device 1, and "X2 side" refers to the back side.

[0113] The printing device 1 prints onto the medium M using an inkjet method. The medium M can be, for example, paper, cloth, or a resin film.

[0114] like Figure 1 As shown, the printing apparatus 1 includes a main body 2 and a support 3 supporting the main body 2. The main body 2 includes a platen 21 supporting a medium M. Furthermore, the main body 2 includes: a printhead 22 that sprays ultraviolet-curable ink onto the medium M; and an ultraviolet irradiation unit 25 that irradiates the ink sprayed onto the medium M with ultraviolet light. The main body 2 includes: an operation panel 26 that receives user input; and a controller 27 that controls the operation of the printing apparatus 1.

[0115] like Figure 2As shown, the printing apparatus 1 includes: an ink supply mechanism 28 that supplies ink to the print head 22; a moving mechanism 29 that moves the print head 22 and the ultraviolet irradiation section 25 in the Y direction; and a feeding mechanism 30 that transports the medium M in the X direction.

[0116] like Figure 3 As shown, the ink supply mechanism 28 has: an ink bottle 281 that stores ink; and an ink supply passage 282 that connects the ink bottle 281 and the print head 22.

[0117] like Figure 1 As shown, the moving mechanism 29 (refer to) Figure 2 The device includes: a carriage 291, a spray head 22, and an ultraviolet irradiation unit 25 mounted on the carriage 291; and a guide rail 292 that guides the carriage 291. The guide rail 292 is arranged along the Y direction of the main body 2. Although not shown in the figure, the moving mechanism 29 includes a belt, a drive pulley and a driven pulley wound with the belt, and a motor that rotates the drive pulley. The carriage 291 is fixed to the drive belt. By rotating the drive belt using the motor, the carriage 291 moves along the guide rail 292 in the Y direction within the main body 2.

[0118] Although the diagram is omitted, the feed mechanism 30 (see reference) Figure 2 It includes a motor, a roller that rotates using the motor, and multiple pinch rollers. The medium M is conveyed in the X direction by rotating the roller while clamping it with the roller and the multiple pinch rollers. The medium M is conveyed from the X2 side to the X1 side. That is, in the conveying direction of the medium M, the X2 side is the upstream side, and the X1 side is the downstream side.

[0119] The printing apparatus 1 moves the carriage 291 in the Y direction using the moving mechanism 29, and feeds the medium M in the X direction using the feeding mechanism 30. Thus, the carriage 291 moves relative to the medium M in both the X and Y directions. While moving the carriage 291, the printing apparatus 1 ejects UV-curable ink from the nozzle 22 onto the medium M. The printing apparatus 1 cures the ink that falls onto the medium M using the UV irradiation unit 25. This allows printing to be performed on the medium M.

[0120] The operation panel 26 can be, for example, a touch panel. The operation panel 26 displays the image output by the controller 27 and accepts operation input from the user. The operation panel 26 can also be composed of, for example, a display for showing images and a switch for accepting operation input.

[0121] The controller 27 controls the operation of various parts of the printing device 1. The controller 27 can be, for example, a microcomputer. The controller 27 includes a processor such as a CPU (Central Processing Unit) and memory such as an HDD (Hard Disk Drive), SSD (Solid State Drive), or RAM (Random Access Memory). The CPU executes programs stored in memory, thereby performing the operations of the printing device 1.

[0122] The controller 27 is equipped with a communication device to receive image data printed on the medium M from an external computer or the like.

[0123] The controller 27 generates printing data for controlling various parts of the printing device 1 based on the input image data. The printing data includes ink dot positions. Ink dot positions refer to the landing positions of the ink ejected from the printhead 22 on the medium M. Ink dot positions are represented, for example, by XY coordinates. The controller 27 converts the position coordinates of each pixel contained in the image into ink dot positions to generate the printing data.

[0124] The controller 27 controls the feed mechanism 30 and the moving mechanism 29 based on the printing data, thereby moving the print head 22 to the ink dot position and ejecting ink.

[0125] like Figure 3 As shown, the printhead 22 has two inkjet heads 23 and 24 (hereinafter referred to as "printheads 23 and 24"). The printheads 23 and 24 are connected to the table 21 (see reference). Figure 1 The medium M on the ) is configured relatively.

[0126] like Figure 4 As shown, nozzles 23 and 24 are arranged in a so-called staggered configuration. Nozzles 23 and 24 are staggered in both the X and Y directions. Nozzle 24 is positioned on the Y2 side of nozzle 23 in the Y direction and on the X1 side of nozzle 23 in the X direction. Nozzle 24 is positioned downstream of nozzle 23 in the direction of medium M transport. When viewed from the Y direction, a portion of nozzle 24 overlaps with nozzle 23.

[0127] The nozzle 23 has eight nozzle sections 231-238 arranged in the Y direction. The nozzle 24 also similarly has eight nozzle sections 241-248 arranged in the Y direction. Figure 4 As shown, end regions 23a and 24a, which are not covered by nozzle portions 231-238 and 241-248, are provided on the X2 side of nozzles 23 and 24. When viewed from the Y direction, the end region 24a of nozzle 24 overlaps with nozzle 23.

[0128] like Figure 3 As shown, nozzles 231-238 and 241-248 are respectively provided on the opposite surfaces of nozzles 23 and 24 that are opposite to the medium M.

[0129] The printheads 23 and 24 are provided with ink supply ports (not shown) that are connected to the ink supply passage 282. Ink is supplied from the ink bottle 281 to the nozzles 231-238 and 241-248 of the printheads 23 and 24 respectively via the ink supply passage 282 and the ink supply ports.

[0130] In this implementation, as an example, inks of four colors—C (cyan), M (magenta), Y (yellow), and K (key plate)—are supplied to printheads 23 and 24. Black is used as an example of a key plate color. Figure 4 In this text, for ease of understanding, the first letters C, M, Y, and K are used to represent the colors of the ink supplied to each nozzle section 231-238 and 241-248.

[0131] like Figure 3 As shown, the nozzle portions 231 to 238 of the printhead 23 are located at the lower part of the printhead 23 facing the medium M. Although not shown in the figure, the printhead 23 is provided with piezoelectric elements corresponding to each nozzle in the nozzle portions 231 to 238. Ink is ejected from the nozzles by driving the piezoelectric elements.

[0132] like Figure 4 As shown, nozzles 231 to 238 are arranged in the Y direction. Nozzles 231, 232, 233, and 234 are arranged from the Y-direction center Yo of the printhead 23 towards Y1. Nozzles 235, 236, 237, and 238 are arranged from the Y-direction center Yo of the printhead 23 towards Y2. Nozzles 231 and 235 eject black ink. Nozzles 232 and 236 eject yellow ink. Nozzles 233 and 237 eject cyan ink. Nozzles 234 and 238 eject magenta ink. In other words, in the printhead 23, nozzles 231 to 238 are arranged in a linearly symmetrical manner with respect to the Y-direction center Yo, with each nozzle ejecting the same color ink positioned relative to the Y-direction center Yo.

[0133] Figure 5 This is a schematic diagram showing the configuration of the nozzles N that constitute the nozzle sections 231 and 235.

[0134] like Figure 5 As shown, nozzle sections 231 and 235 are each composed of multiple nozzle rows Nq. Each nozzle row Nq consists of multiple nozzles N arranged at a certain interval D in the X direction. Each nozzle row Nq has a length L in the X direction. The multiple nozzle rows Nq are arranged at open intervals in the Y direction.

[0135] The nozzles N of nozzle sections 231 and 235 are arranged in such a way that their phases in the X direction are different from each other. That is, the nozzles N of each of nozzle sections 231 and 235 are arranged alternately in the X direction. When viewed from the Y direction, the nozzles N constituting nozzle section 235 are located at the interval D between the nozzles N constituting nozzle section 231. In other words, when viewed from the Y direction, the nozzles N of nozzle sections 231 and 235 that eject ink of the same color are arranged continuously in the X direction.

[0136] Although the illustrations are omitted, the other nozzle sections have the same structure as nozzle sections 231 and 235. Moreover, similar to nozzle sections 231 and 235, the nozzle sections (nozzle sections 232 and 236; nozzle sections 233 and 237; nozzle sections 234 and 238) that spray ink of the same color are arranged in such a way that the phases of each nozzle in the X direction are different from each other.

[0137] like Figure 4 As shown, the nozzle sections 241 to 248 of printhead 24 have the same structure as those of printhead 23, so detailed descriptions are omitted. In printhead 24, similarly to printhead 23, nozzle sections 241 to 248 are arranged in a manner that the nozzle sections ejecting ink of the same color are positioned linearly symmetrically with respect to the center Yo in the Y direction. Nozzle sections 241 and 245 eject black ink. Nozzle sections 242 and 246 eject yellow ink. Nozzle sections 243 and 247 eject cyan ink. Nozzle sections 244 and 248 eject magenta ink. The nozzle sections ejecting ink of the same color (nozzle sections 241 and 245; nozzle sections 242 and 246; nozzle sections 243 and 247; nozzle sections 244 and 248) are arranged such that the phases of their respective nozzles in the X direction are different from each other.

[0138] Furthermore, the structure shown here is only an example, and the settings for the printhead, nozzle section, nozzle array, number of nozzles, number of ink colors, and ink color distribution relative to each nozzle section can be appropriately changed.

[0139] When viewed from the Y direction, the nozzle portions 231-238 of the nozzle head 23 and the nozzle portions 241-248 of the nozzle head 24 are continuous in the X direction. The nozzles 23 and 24 are arranged with their positions staggered in the Y direction, but this is achieved using the moving mechanism 29 (see reference). Figure 2 This allows the printhead 22 to move in the Y direction, enabling printheads 23 and 24 to eject ink from the same position in the Y direction. That is, each printhead has a column Nq of length L (see reference). Figure 5 The nozzle portion of nozzle 23 and the nozzle portion of nozzle 24 can be considered as forming a continuous nozzle array with a length of 2L in the X direction.

[0140] Specifically, the combination of nozzle sections located at the same distance from the center Yo in the Y direction within each nozzle 23, 24 constitutes a continuous nozzle array in the X direction. For example... Figure 4 As shown, the combinations of nozzle section 231 and nozzle section 241, nozzle section 232 and nozzle section 242, nozzle section 233 and nozzle section 243, nozzle section 234 and nozzle section 244, nozzle section 235 and nozzle section 245, nozzle section 236 and nozzle section 246, nozzle section 237 and nozzle section 247, and nozzle section 238 and nozzle section 248 each form a continuous nozzle array in the X direction.

[0141] like Figure 4 As shown, the nozzle head 23 is provided with an inclined axis TA along the Z direction. The nozzle head 23 is configured to be able to rotate about the inclined axis TA using an inclined mechanism (not shown). The inclined axis TA is located in the end region 23a of the nozzle head 23 on the X2 side. The inclined axis TA is located near the corner of the end region 23a on the Y2 side.

[0142] like Figure 3 As shown, a tilt adjustment knob 225 (hereinafter referred to as "knob 225") for the spray head 23 is provided on the front side of the spray head 23. The knob 225 is linked to a tilting mechanism (not shown). When the knob 225 is moved clockwise, the spray head 23 rotates clockwise (see reference). Figure 4 Rotate the knob 225 counterclockwise. When the knob 225 is moved counterclockwise, the nozzle 23 rotates counterclockwise (refer to...). Figure 4 Rotate.

[0143] Knob 225, for example, can be set to a dial knob that provides a click feedback when rotated a specified angle.

[0144] like Figure 4 As shown, in the nozzle 24, similarly to the nozzle 23, an inclined shaft TA is provided near the corner of the end region 24a on the X2 side, near the Y2 side.

[0145] The nozzle 24 is also provided with a tilting mechanism (not shown), which can rotate around the tilting axis TA in the same way as the nozzle 23.

[0146] like Figure 3 As shown, a knob 225 with the same function as the knob 225 of the nozzle 23 is provided on the front side of the nozzle 24.

[0147] The nozzle 24 is also provided with a displacement mechanism (not shown) such as a slider that moves the nozzle 24 relative to the X direction. On the front side of the nozzle 24, in addition to the knob 225, there is also a displacement adjustment knob 226 (hereinafter simply referred to as "knob 226"). The knob 226 is linked to the displacement mechanism (not shown). For example, when the knob 226 is moved clockwise, the nozzle 24 moves towards the X2 side in the X direction (see reference). Figure 4 Displacement. When knob 226 is moved counterclockwise, nozzle 24 moves towards the X1 side in the X direction (refer to...). Figure 4 Displacement. Knob 226, for example, can be set to a dial knob that provides a click feedback when rotated a specified angle.

[0148] The tilting mechanism and displacement mechanism of nozzles 23 and 24 are provided for tasks such as nozzle inspection, cleaning, and replacement. After operation, adjustment is made using knob 225 to ensure that nozzles 23 and 24 are in a non-tilted state. A non-tilted state means that the nozzle array Nq of each nozzle 23 and 24 is parallel to the X direction.

[0149] Furthermore, the position of the nozzle 24 in the X direction is adjusted using the knob 226 so that the end region 24a of the nozzle 24 overlaps with the nozzle 23 when viewed from the Y direction.

[0150] By adjusting the positions of printheads 23 and 24 in this way, the ink droplets of printheads 23 and 24 are aligned.

[0151] Figure 6 This is a diagram showing a printing example where the ink droplets from printheads 23 and 24 are in the same position.

[0152] Figure 6 This example illustrates how nozzles 23 and 24 form a continuous line S at position Ya in the Y direction.

[0153] As described above, when printing on the medium M, the controller 27 controls the moving mechanism 29 to move the printheads 23 and 24 to the positions of the ink dots included in the printing data and eject ink from the nozzles.

[0154] For example, such as Figure 6 As shown in (a), ink is ejected from the nozzle section 234 of the printhead 23 at position Ya in the Y direction, forming a line S1 parallel to the X direction. Line S1 has a length L corresponding to the length in the X direction of the nozzle array Nq constituting the nozzle section 234. Next, as... Figure 6As shown in (b), the nozzle portion 244 of the printhead 24 is moved to a position Ya in the Y direction and ink is ejected, forming a line S2 parallel to the X direction. The line S2 has a length L in the X direction corresponding to the nozzle array Nq constituting the nozzle portion 244. The X1 side of the line S1 formed by the nozzle portion 234 is connected to the X2 side of the line S2 formed by the nozzle portion 244. Thus, a continuous line S with a length of 2L in the X direction is formed.

[0155] Thus, by moving printheads 23 and 24 from the Y2 side to the Y1 side in the Y direction while ejecting ink, the nozzles of printheads 23 and 24 can be treated as a continuous nozzle array in the X direction. However, if the ink droplet positions of printheads 23 and 24 are inconsistent, it may affect the continuity of the nozzles of printheads 23 and 24.

[0156] Users adjust the positions of printheads 23 and 24 visually. Therefore, sometimes tilting and positional shifts in printheads 23 and 24 occur that are not perceptible to the naked eye. Alternatively, tilting and positional shifts may also occur due to manufacturing errors or wear of printheads 23 and 24. In these cases, even if the controller 27 controls printheads 23 and 24 to eject ink to the same ink droplet position on the print data, the landing position (actual ink droplet position) of the ink ejected from printheads 23 and 24 may shift. Inconsistent ink landing positions (actual ink droplet positions) in printheads 23 and 24 may affect the continuity between the nozzle sections of printheads 23 and 24, thereby impacting print quality.

[0157] Figure 7 This is a diagram illustrating a printing example where the ink droplet positions of printheads 23 and 24 are inconsistent. Figure 7 and Figure 6 Similarly, this illustrates an example where line S1 is formed by the nozzle portion 234 of nozzle 23 at position Ya in the Y direction, and line S2 is formed by the nozzle portion 244 of nozzle 24. Furthermore, Figure 7 The tilt and positional offset of lines S1 and S2 are exaggerated.

[0158] Figure 7 (a) is a diagram showing a printing example where the printhead 24 is tilted counterclockwise.

[0159] In this case, the line S2 formed by the nozzle 24 will also tilt and become non-parallel to the X direction.

[0160] Figure 7 (b) is a diagram showing a printing example where the printheads 23 and 24 have a positional offset in the Y direction.

[0161] exist Figure 7In (b), it is shown that the ink drop position of the printhead 24 is offset in the Y direction Y1 relative to the ink drop position of the printhead 23.

[0162] The line S1 formed by nozzle 23 is located at position Ya in the Y direction, while the line S2 formed by nozzle 24 is located on the Y1 side, which is closer to Ya than Ya.

[0163] Figure 7 (c) is a diagram showing a printing example where the printheads 23 and 24 have a positional offset in the X direction.

[0164] exist Figure 7 In (c), it is shown that the ink droplet position of printhead 24 is offset to the X1 side in the X direction relative to the ink droplet position of printhead 23. In this case, when viewed from the Y direction, a gap is generated between the line S1 formed by printhead 23 and the line S2 formed by printhead 24.

[0165] Thus, in Figure 7 In any of the examples shown, it is impossible to form a suitable structure. Figure 6 As shown, there is a continuous line S with a length of 2L in the X direction. That is, if the ink droplet positions of the printheads 23 and 24 are inconsistent due to tilting or positional offset, it may affect the quality of the print formed by the printheads 23 and 24.

[0166] In this embodiment, the controller 27 executes a correction mode for correcting the tilt and positional offset of the nozzles 23 and 24. The correction mode is executed, for example, by the user selecting it from a menu displayed on the operation panel 26.

[0167] In calibration mode, controller 27 prints the following test pattern onto medium M.

[0168] • Test pattern 50 for tilt correction

[0169] • Test pattern 60 for position offset correction in the Y direction

[0170] • Test pattern 70 for position offset correction in the X direction

[0171] For example, the following steps can be followed to perform calibration using test patterns 50, 60, and 70.

[0172] Figure 8 This is a flowchart illustrating an example of a calibration step.

[0173] First, use test pattern 50 to correct the tilt of nozzles 23 and 24 (step 1).

[0174] Next, using test pattern 60, the positional offset of nozzles 23 and 24 in the Y direction is corrected (step 2).

[0175] Next, using test pattern 70, the positional offset of nozzles 23 and 24 in the X direction is corrected (step 3).

[0176] The following details the contents of each test pattern and the calibration method used for each test pattern.

[0177] Figure 9 This is a diagram representing test pattern 50 used for tilt correction.

[0178] Figure 9 The X, Y, and Z directions indicate that medium M is located on platform 21 (refer to...). Figure 1 The direction when it is up.

[0179] like Figure 9 As shown, the test pattern 50 for tilt correction is divided into region 51 formed by nozzle 23 and region 52 formed by nozzle 24. Region 51 is further divided into region 51A for coarse adjustment and region 51B for fine adjustment. Region 52 is further divided into region 52A for coarse adjustment and region 52B for fine adjustment.

[0180] The area 51A for coarse adjustment is comprised of the nozzle section 231 (first nozzle section) and nozzle section 235 (second nozzle section) of the nozzle 23 (see reference). Figure 4 The black pattern formed by the formation.

[0181] The fine-tuning area 51B is formed by the nozzle section 234 (third nozzle section) and nozzle section 238 (fourth nozzle section) of the nozzle 23 (see reference). Figure 4 The pattern formed is magenta.

[0182] The area 52A for coarse adjustment is comprised of the nozzle section 241 (first nozzle section) and nozzle section 245 (second nozzle section) of the nozzle 24 (see reference). Figure 4 The black pattern formed by the formation.

[0183] The fine-tuning area 52B is comprised of the nozzle section 244 (third nozzle section) and nozzle section 248 (fourth nozzle section) of the nozzle 24 (see reference). Figure 4 The pattern formed is magenta.

[0184] That is, each area is formed by a combination of nozzles of printheads 23 and 24 that spray ink of the same color.

[0185] Regions 51A, 51B, 52A, and 52B are arranged within a rectangular base 53, with counter-clockwise arrows 54 (first figure) and clockwise arrows 55 (second figure) forming a structure. As described above, regions 51A, 51B, 52A, and 52B are each composed of ink of the same color, but... Figure 9 To make it easier to understand, different shading lines are used to mark base 53 and arrows 54 and 55.

[0186] Regions 51A, 51B, 52A, and 52B have the same structure, so the structure of region 51A will be described in detail representatively.

[0187] Figure 10 yes Figure 9 An enlarged view of the portion enclosed by box A.

[0188] Figure 9 The substrate 53 shown is composed of Figure 10 The set of multiple baselines 530 (first baselines) extending along the Y direction is shown. The multiple baselines 530 are arranged in the X direction with small gaps between them, so that they are visually recognized as a rectangular base 53 as a whole.

[0189] Figure 9 Arrows 54 and 55 shown are respectively from Figure 10 The diagram shows a set of rectangular blocks 540 (first block) and a set of rectangular blocks 550 (second block). Blocks 540 and 550 are formed between multiple baselines 530. Blocks 540 and 550 are formed with a gap in the Y direction. Thus, arrows 54, which are part of the set of blocks 540, and arrows 55, which are part of the set of blocks 550, are arranged in a staggered manner in the Y direction without overlapping.

[0190] The block 540 that forms arrow 54 is formed adjacent to baseline 530 on the X1 side of baseline 530 (lower side in the figure). The collection of multiple blocks 540 is visually recognized as arrow 54 in a counterclockwise direction.

[0191] The block 550 that forms arrow 55 is formed adjacent to baseline 530 on the X2 side of baseline 530 (upper side in the figure). The collection of multiple blocks 550 is visually recognized as clockwise arrow 55.

[0192] Figure 11 This is a diagram illustrating the method of forming test pattern 50.

[0193] Figure 11 An example of a method for forming region 51A is shown. The baseline 530 of region 51A is formed by the nozzle portion 231 of the nozzle 23. Blocks 540 and 550 are formed by the nozzle portion 235 of the nozzle 23. Figure 11The diagram schematically illustrates the arrangement of the nozzles constituting nozzle sections 231 and 235, and the correspondence between the baseline 530 formed by each nozzle and the blocks 540 and 550. Figure 11 In the image, the nozzle is shown as a rectangle for ease of understanding.

[0194] like Figure 11 As shown, the nozzles N1a, N1b, N1c, N1d, N1e... of the nozzle section 231 are arranged from the X2 side toward the X1 side in the X direction.

[0195] The nozzles N5a, N5b, N5c, N5d, N5e, N5f... of the nozzle section 235 are arranged from the X2 side toward the X1 side in the X direction. The nozzles of the nozzle section 235 are arranged in a phase-shifted manner relative to the nozzles of the nozzle section 231 in the X direction. That is, the nozzles of the nozzle section 231 and the nozzles of the nozzle section 235 are arranged alternately in the X direction.

[0196] exist Figure 11 The diagram illustrates three combinations of baseline 530 with blocks 540 and 550: P1, P2, and P3.

[0197] In assembly P1, baseline 530 is formed by nozzle N1a (first nozzle). Block 540 is formed by nozzle N5b (second nozzle) located on the X1 side of nozzle N1a. Block 550 is formed by nozzle N5a (third nozzle) located on the X2 side of nozzle N1a.

[0198] Thus, blocks 540 and 550 are formed adjacent to baseline 530 on the X1 and X2 sides of baseline 530, respectively. Assembly P1 has a width in the X direction corresponding to the three ink dots.

[0199] There is a gap between combination P1 and combination P2 corresponding to one ink dot. That is, no ink is ejected from nozzle N1b.

[0200] The baseline 530 of assembly P2 is formed by nozzle N1c (first nozzle). Block 540 is formed by nozzle N5d (second nozzle) located on the X1 side of nozzle N1c. Block 550 is formed by nozzle N5c (third nozzle) located on the X2 side of nozzle N1c.

[0201] There is a gap between combination P2 and combination P3 corresponding to one ink dot. That is, no ink is ejected from nozzle N1d.

[0202] The baseline 530 of assembly P3 is formed by nozzle N1e (first nozzle). Block 540 is formed by nozzle N5f (second nozzle) on the X1 side of nozzle N1e. Block 550 is formed by nozzle N5e (third nozzle) on the X2 side of nozzle N1e.

[0203] Similarly to combination P1, combinations P2 and P3 have a width in the X direction corresponding to the width of the three ink dots.

[0204] Thus, the baseline 530 is formed by using the nozzles of the nozzle section 231 every other one. Block 540 is formed by the nozzle of the nozzle section 235 adjacent to the nozzle of the nozzle section 231 forming the baseline 530 on one side (X1 side) in the X direction. Block 550 is formed by the nozzle of the nozzle section 235 adjacent to the nozzle of the nozzle section 231 forming the baseline 530 on the other side (X2 side) in the X direction. That is, blocks 540 and 550 are arranged in a manner that staggers each other in position in the X direction without overlapping.

[0205] Figure 11 This indicates the test pattern 50 formed when the nozzle 23 is not tilted. For example... Figure 4 As shown, the nozzle portion 231 forming the baseline 530 is farther from the tilt axis TA than the nozzle portion 235 forming the blocks 540 and 550. Due to the difference in distance from this tilt axis TA, the positional relationship between the baseline 530 and the blocks 540 and 550 will change when the nozzle 23 is tilted, as will be described in detail later.

[0206] Other areas were also formed using the same method as area 51A.

[0207] exist Figure 9 In the fine-tuning area 51B shown, the base 53 (baseline 530, second baseline) is formed by the nozzle portion 234 (third nozzle portion) of the nozzle 23. Arrows 54 (block 540, third block) and 55 (block 550, fourth block) are formed by the nozzle portion 238 (fourth nozzle portion).

[0208] In the coarse adjustment area 52A, the base 53 (baseline 530, first baseline) is formed by the nozzle portion 241 (first nozzle portion) of the nozzle 24. Arrows 54 (block 540, first block) and 55 (block 550, second block) are formed by the nozzle portion 245 (second nozzle portion).

[0209] In the fine-tuning area 52B, the base 53 (baseline 530, second baseline) is formed by the nozzle portion 244 (third nozzle portion) of the nozzle 24. Arrows 54 (block 540, third block) and 55 (block 550, fourth block) are formed by the nozzle portion 248 (fourth nozzle portion).

[0210] Thus, in any region, the base 53 (baseline 530) is formed by a nozzle portion that is farther away from the tilt axis TA, and the arrows 54 and 55 (blocks 540 and 550) are formed by nozzle portions that are closer to the tilt axis TA.

[0211] Figure 12This is a diagram illustrating the change in test pattern 50 when the nozzle 23 is tilted.

[0212] Figure 12 (a) is a diagram showing the displacement of nozzle sections 234 and 238 when the nozzle 23 is tilted clockwise CW. Figure 12 In (a), to facilitate understanding of the effect of the nozzle 23's tilt, nozzle sections 234 and 238 with a longer distance between them are shown. Additionally, in Figure 12 In (a), for ease of understanding, the positional relationship of nozzles 234 and 238 is schematically shown.

[0213] Figure 12 (b) is a diagram illustrating the change in region 51B formed by nozzle sections 234 and 238 when nozzle 23 is tilted clockwise CW.

[0214] Figure 12 (a) The dashed line represents the nozzle 23 in its untilted state, and the solid line represents the nozzle 23 tilted clockwise (CW). Figure 12 As shown in (a), when the nozzle 23 is tilted clockwise CW, the nozzle portions 234 and 238 of the nozzle 23 are displaced in the X direction toward the X2 side.

[0215] like Figure 12 As shown in (b), the baseline 530 and blocks 540 and 550 formed by these nozzles also shift in the X direction according to the displacement of the nozzle portions 234 and 238.

[0216] Furthermore, due to the tilt of the nozzle 23, the nozzle sections 234 and 238 also shift in the Y direction, but... Figure 12 In (b), for ease of understanding, displacement in the Y direction is ignored, and baseline 530 and blocks 540 and 550 are shown parallel to the Y direction.

[0217] like Figure 12 As shown in (a), when the nozzle head 23 rotates, the nozzle portion further away from the tilting axis TA, which is the center of rotation, has a greater displacement in the X direction. The displacement ΔXA in the X direction of the nozzle portion 234, which is farther from the tilting axis TA, is greater than the displacement ΔXB in the X direction of the nozzle portion 238, which is closer to the tilting axis TA (ΔXA > ΔXB).

[0218] The difference in displacement between nozzle sections 234 and 238 is also reflected in the displacement in the X direction of the baseline 530 and blocks 540 and 550 formed by them. That is, the displacement in the X direction of the baseline 530 is greater than the displacement in the X direction of blocks 540 and 550. Therefore, as Figure 12As shown in (b), the baseline 530 of the assembly P1 to P3 is relatively displaced towards the X2 side relative to blocks 540 and 550 within the same assembly. Figure 11 As shown, with nozzle 23 not tilted, baseline 530 is located between blocks 540 and 550. Figure 12 As shown in (b), due to the displacement of baseline 530 towards the X2 side, baseline 530 of combination P1 separates from block 540 of the same combination P1, while locally overlapping with block 550. Combinations P2 and P3 also undergo the same change. This change in the relative position of baseline 530 with blocks 540 and 550 occurs throughout region 51B.

[0219] In this context, from a human visual perspective, within the same area, if lines are far apart, the color appears darker; if lines are close together or touching, the color appears lighter.

[0220] That is, the following phenomenon occurs: the set of blocks 540 that are separated from the baseline 530, i.e., arrow 54, appears denser than the set of blocks 550 that locally overlap with the baseline 530, i.e., arrow 55.

[0221] Here, in Figure 12 In (a), since nozzle 23 is tilted clockwise (CW), knob 225 needs to be rotated counterclockwise (CCW) to adjust the tilt of nozzle 23. Figure 12 As shown in (b), the user can correct the tilt of the nozzle 23 by turning the knob 225 counterclockwise CCW in the direction indicated by the seemingly denser arrow 54.

[0222] Figure 13 This is a diagram illustrating the change in test pattern 50 when the nozzle 23 is tilted.

[0223] Figure 13 (a) is a diagram schematically showing the displacement of nozzle portions 234 and 238 when the nozzle 23 is tilted counterclockwise (CCW). Figure 13 (b) is a diagram illustrating the change in test pattern 50 and the rotation direction of knob 225 when nozzle 23 is tilted counterclockwise CCW. Figure 13 (b) and Figure 12 Similarly, (b) disregards displacement in the Y direction and shows baseline 530 and blocks 540, 550 parallel to the Y direction.

[0224] like Figure 13 As shown in (a), when the nozzle 23 is tilted counterclockwise CCW, the nozzle portions 234 and 238 of the nozzle 23 are displaced in the X direction toward the X1 side. The displacement ΔXC of the nozzle portion 234, which is farther from the tilt axis TA, is greater than the displacement ΔXD of the nozzle portion 238, which is closer to the tilt axis TA, in the X direction (ΔXC > ΔXD).

[0225] like Figure 13 As shown in (b), baseline 530 is displaced relative to blocks 540 and 550 towards the X1 side. The baseline 530 of the combination P1 to P3 is separated from the block 550 of the same combination, and partially overlaps with block 540. As a result, the arrows 55, which are part of the set of blocks 550, appear to be denser than the arrows 54, which are part of the set of blocks 540.

[0226] Here, in Figure 13 In (a), since the nozzle 23 is tilted counterclockwise (CCW), the knob 225 needs to be turned clockwise (CW) to adjust the tilt of the nozzle 23. That is, the user can correct the tilt of the nozzle 23 by turning the knob 225 clockwise (CW) in the direction indicated by the seemingly denser arrow 55.

[0227] Thus, blocks 540 and 550 are formed on the X1 and X2 sides of the baseline 530. Furthermore, the nozzle portions forming blocks 540 and 550 use nozzle portions closer to the tilt axis TA than the nozzle portion forming the baseline 530. As a result, a difference in displacement occurs between the baseline 530 and blocks 540 and 550 when the nozzle 23 is tilted, causing the baseline 530 to shift relative to blocks 540 and 550. The baseline 530 shifts to either the X1 or X2 side depending on the tilt direction of the nozzle 23, resulting in a difference in distance between it and each of the blocks 540 and 550. Due to this difference in distance, arrows 54 and 55 produce a difference in concentration. The user can determine whether the correction direction for the tilt of the nozzle 23 is the X2 side (clockwise CW) or the X1 side (counterclockwise CCW).

[0228] Here, the individual baselines 530 and blocks 540, 550 are very small. For example, if only one combination P1 of baselines 530 and blocks 540, 550 is printed on media M, a magnifying glass is needed to determine the difference in their distances.

[0229] In this embodiment, a combination of multiple baselines 530 and blocks 540 and 550 is printed. Arrows 54 and 55, which are sets of blocks 540 and 550 respectively, are formed on a base 53, which is a set of baselines 530. As described above, visually, within the same area, lines appear darker when they are far apart and lighter when they are close together or touching. This difference in density is more easily visually perceived in the arrows 54 and 55, which are sets of lines.

[0230] In this embodiment, the graphic formed by the assembly of blocks 540 and 550 is also designated as arrows 54 and 55 representing the correction direction of the tilt of the nozzle 23 (the rotation direction of the tilt axis TA). That is, arrow 54, which becomes denser due to the tilt of the nozzle 23 towards the X2 side (clockwise CW), is designated as a counterclockwise CCW arrow. Arrow 55, which becomes denser due to the tilt of the nozzle 23 towards the X1 side (counterclockwise CCW), is designated as a clockwise CW arrow.

[0231] For example, when printing only a combination P1 of baseline 530 and blocks 540, 550 on media M, it is difficult to intuitively determine which direction to turn knob 225 based on the difference in their distances. By assigning a mark indicating the direction opposite to the tilt direction of printhead 23, i.e., the correction direction, to arrows 54, 55, which appear darker according to the tilt direction of printhead 23, the user can intuitively determine the direction to turn knob 225.

[0232] In test pattern 50, region 51, representing the tilt of nozzle 23, and region 52, representing the tilt of nozzle 24, are formed in the same medium M. Therefore, the user can adjust both nozzles 23 and 24 according to a test pattern 50.

[0233] When printheads 23 and 24 are not tilted, there will be no difference in density between arrows 54 and 55. The user rotates knob 225 based on the density difference between arrows 54 and 55 and prints test pattern 50 again to confirm the change in density between arrows 54 and 55. The user repeats this operation to adjust printheads 23 and 24 until the density difference between arrows 54 and 55 disappears.

[0234] like Figure 9 As shown, region 51 of test pattern 50 is divided into region 51A for coarse adjustment and region 51B for fine adjustment. Region 52 is also divided into region 52A for coarse adjustment and region 52B for fine adjustment. In the initial stage when the nozzles 23 and 24 are significantly tilted, the user uses regions 51A and 52A for coarse adjustment, and in the stage after tilt correction, uses regions 51B and 52B for fine adjustment. Furthermore, Figure 9 The diagram illustrates the tilt correction stage using areas 51B and 52B for fine-tuning.

[0235] Regions 51A and 52A for coarse adjustment are formed by a combination of nozzles with a shorter (closer) distance in the Y direction between them. Regions 51B and 52B for fine adjustment are formed by a combination of nozzles with a longer (farther) distance in the Y direction between them. Therefore, in regions 51B and 52B for fine adjustment, the effect of the tilt of nozzles 23 and 24 is greater than that in regions 51A and 52A for coarse adjustment.

[0236] Figure 14 This is a diagram illustrating the positional relationship of the nozzle section of the nozzle 23.

[0237] Figure 14 (a) schematically represents the formation area 51A of nozzle 23 (see reference). Figure 9 The nozzle portions 231 and 235 and the forming area 51B (refer to) Figure 9 A diagram showing the positional relationship of nozzle sections 234 and 238. Figure 14 (b) is a diagram illustrating the difference in displacement of each nozzle section when the nozzle 23 is tilted.

[0238] like Figure 14 As shown in (a), the distance D3 between the nozzle portions 234 and 238 forming the fine adjustment region 51B is longer than the distance D2 between the nozzle portions 231 and 235 forming the coarse adjustment region 51A. Furthermore, the nozzle portion 234 of the baseline 530 forming region 51B is farther from the tilt axis TA than the nozzle portion 231 of the baseline 530 forming region 51A. The nozzle portions 238 of the blocks 540 and 550 forming region 51B are closer to the tilt axis TA than the nozzle portions 235 of the blocks 540 and 550 forming region 51A.

[0239] Based on such positional relationships, such as Figure 14 As shown in (b), when the nozzle 23 is tilted, the difference in displacement in the X direction between nozzle sections 234 and 238 (ΔXA-ΔXB) is greater than the difference in displacement in the X direction between nozzle sections 231 and 235 (ΔXE-ΔXF). Due to this difference in displacement, when the nozzle 23 is tilted, in region 51B, the relative displacement between baseline 530 and blocks 540 and 550 is larger than that in region 51A.

[0240] Figure 15 This is a diagram illustrating the displacement in the X direction of regions 51A and 51B when the nozzle 23 is tilted significantly. Figure 15 (a) represents region 51A. Figure 15 (b) represents region 51B. Figure 15 This indicates that nozzle 23 is tilted clockwise.

[0241] like Figure 15 As shown in (a), during the phase when the nozzle 23 is tilted more, the baseline 530 also shifts relatively significantly towards the X2 side in region 51A. The baseline 530 of the combination P1 and P2 partially overlaps with block 550 within the same combination and separates from block 540. As a result, arrow 54, corresponding to the rotation direction (counterclockwise) of knob 225, appears denser.

[0242] On the other hand, in region 51B, baseline 530 is shifted to the X2 side to a greater extent than in region 51A. The baseline 530 of combinations P1 and P2 does not overlap with block 550 within the same combination. Moreover, the baseline 530 of combination P2 is closer to block 540 of other combination P1. As a result, there is a possibility that the difference in concentration between arrows 54 and 55 is unclear, and that arrow 55, which is opposite to the rotation direction of knob 225 (counterclockwise), may appear denser.

[0243] Therefore, in the initial stage when the nozzle 23 is tilted more, coarse adjustments are made using the area 51A where the tilt of the nozzle 23 has less impact.

[0244] Figure 16 This is a diagram illustrating the displacement in the X direction of regions 51A and 51B when the nozzle 23 is tilted relatively small. Figure 16 (a) represents region 51A. Figure 16 (b) represents region 51B. Figure 16 This indicates that nozzle 23 is tilted clockwise.

[0245] When coarse adjustments are made and the tilt of nozzle 23 decreases, the displacement of baseline 530 in region 51A decreases. The baseline 530 of combination P1 and P2 does not overlap with block 550, and the distance between it and block 540 also becomes closer, making it difficult to represent the difference in concentration between arrows 54 and 55.

[0246] On the other hand, in region 51B, the displacement of baseline 530 is larger than that in region 51A. Therefore, baseline 530 partially overlaps with block 550 and separates from block 540 on the X1 side. As a result, arrow 54, corresponding to the rotation direction (counterclockwise) of knob 225, appears thicker.

[0247] In this way, during the stage of correcting the tilt of the nozzle 23, the area 51B where the tilt of the nozzle 23 has a greater impact can be used to make fine adjustments to the angle of the nozzle 23.

[0248] Although detailed explanations are omitted, for printhead 24, coarse adjustments can be made using area 52A, and fine adjustments can be made using area 52B. In test pattern 50, areas 51A and 52A for coarse adjustments and areas 51B and 52B for fine adjustments are printed on the same medium M. The user does not need to select between coarse and fine adjustment modes for printing. Because the user can compare areas 51A and 52A with areas 51B and 52B in test pattern 50, the transition from coarse to fine adjustments is smooth.

[0249] In coarse and fine adjustments, the amount by which the nozzles 23 and 24 are rotated using knob 225 can also be different.

[0250] For example, in coarse adjustment, the knob 225 is rotated by an amount corresponding to 5 clicks; in contrast, in fine adjustment, the knob 225 can be rotated by an amount corresponding to 3 clicks.

[0251] In addition, such as Figure 9 As shown, two sets of arrows 54 and 55 are printed in each of regions 51A, 51B, 52A, and 52B. Even with only one set of arrows 54 and 55, there is a possibility that the concentration difference cannot be properly represented due to errors. In this embodiment, multiple sets of arrows 54 and 55 are printed to account for these errors.

[0252] Users can adjust the settings in areas 51A, 51B, 52A, and 52B to eliminate the difference in concentration between the two sets of arrows 54 and 55. Furthermore, more than three sets of arrows 54 and 55 can be printed in each of the areas 51A, 51B, 52A, and 52B.

[0253] If the tilt correction of nozzles 23 and 24 using test pattern 50 is completed, then the position offset correction in the Y direction using test pattern 60 is performed next. Figure 8 Step 2).

[0254] The test pattern 60 is formed by a combination of nozzle portions that form a continuous row of nozzles in the nozzles 23 and 24. As described above, there are eight combinations in the embodiment, but in step 2, a combination of only one nozzle portion is used to form the test pattern 60.

[0255] Here, an example of forming a test pattern 60 by combining the nozzle portion 234 of the nozzle 23 and the nozzle portion 244 of the nozzle 24 will be described.

[0256] Furthermore, printheads 23 and 24 do not have a displacement mechanism in the Y direction. In this embodiment, if a positional offset in the Y direction is confirmed in the test pattern 60, the positional offset in the Y direction is corrected by correcting the ink dot position data included in the print data.

[0257] Figure 17 This is a diagram of test pattern 60 used for position offset correction in the Y direction.

[0258] Figure 18 This is a diagram illustrating the method for forming test pattern 60. Figure 18 (a) is a diagram illustrating the formation of the first line 610. Figure 18 (b) is a diagram illustrating the formation of the second line 620.

[0259] Figure 17 and Figure 18 The X, Y, and Z directions indicate that medium M is located on platform 21 (refer to...). Figure 1 The direction when it is up. Figure 17 and Figure 18 The test pattern 60 represents the pattern formed when the ink droplets of printheads 23 and 24 are in the same position.

[0260] like Figure 17 As shown, the test pattern 60 has a first line 61 formed by the nozzle portion 234 of the nozzle 23 and a second line 62 formed by the nozzle portion 244 of the nozzle 24.

[0261] like Figure 18 As shown in (a), the first line 61 is a line extending parallel to the X direction. A plurality of first lines 61 are arranged at intervals D4 in the Y direction to form a first line portion 610 having a width W in the Y direction.

[0262] like Figure 17 As shown, in the test pattern 60, a plurality of first line portions 610 are formed at open intervals in the Y direction. Figure 17 In the middle, it represents an example of forming 4 first line parts 610.

[0263] like Figure 18 As shown in (b), the second line 62 is a line extending parallel to the X direction. A plurality of second lines 62 are arranged at intervals D4 in the Y direction to form a second line portion 620 having a width W in the Y direction.

[0264] The second line 62 is formed in the Y direction between multiple first lines 61. The second line 62 is located within the interval D4 between the first lines 61 in the Y direction. The second line 62 is formed such that its position is offset towards the X2 side relative to the first lines 61 in the X direction. When viewed from the Y direction, the first lines 61 and the second line 62 partially overlap.

[0265] That is, the test pattern 60 has an overlap portion 630 where the first line 61 and the second line 62 overlap when viewed from the Y direction. In the overlap portion 630, the first line 61 and the second line 62 are arranged alternately in the Y direction. In other words, in the overlap portion 630, the second line 62 is configured to fill the interval D4 between adjacent first lines 61.

[0266] The actual interval D4 is very small. Therefore, as Figure 17 As shown, when the first line 61 and the second line 62 are consistent with the predetermined range, the overlapping part 630 is visually identified by the naked eye as an area filled with ink, that is, a fully coated area.

[0267] like Figure 17 As shown, a second line portion 620 is formed every other one of the four first line portions 610. That is, an overlapping portion 630 is formed between two first line portions 610. No overlapping portion 630 is formed between the first line portions 610 in between.

[0268] like Figure 17 As shown, the test pattern 60 has a first reference line 64 formed on the Y1 side of each first line portion 610. The first reference line 64 is formed by the nozzle portion 234 of the nozzle 23, just like the first line portion 610.

[0269] like Figure 18 As shown, the first reference line 64 is a line extending parallel to the X direction and has the same length in the X direction as the first line 61. The first reference line 64 is formed in the X direction at the same position as the first line portion 610.

[0270] The test pattern 60 has a second reference line 65 formed on the Y1 side of each second line portion 620. The second reference line 65 is formed by the nozzle portion 244 of the nozzle 24, just like the second line portion 620.

[0271] The second reference line 65 is a line extending parallel to the X direction, having the same length in the X direction as the second line 62. The second reference line 65 is formed in the X direction at the same position as the second line portion 620. The second reference line 65 is formed in the Y direction at the same position as the first reference line 64. The second reference line 65 is formed offset from the X2 side of the first reference line 64. That is, the first reference line 64 and the second reference line 65 are printed on the medium M with partial overlap. Therefore, the first reference line 64 and the second reference line 65 are visually recognized as a continuous line.

[0272] like Figure 17 As shown, the test pattern 60 has a sample block 660. The sample block 660 is formed on the Y2 side of the first line portion 610. The sample block 660 is a rectangular pattern filled with a single-color ink, known as "full coverage". The sample block 660 is formed only by the nozzle portion 234 of the print head 23. The sample block 660 is formed in the X direction at the same position as the first line portion 610.

[0273] The test pattern 60 is formed while the printheads 23 and 24 are moved in the same direction. The first line portion 610, the first reference line 64, and the sample block 660 of the test pattern 60 are formed, for example, by ejecting ink while the printhead 23 is moved from the Y2 side to the Y1 side in the Y direction. The second line portion 620 and the second reference line 65 of the test pattern 60 are formed, for example, by ejecting ink while the printhead 24 is moved from the Y2 side to the Y1 side in the Y direction, similar to the printhead 23.

[0274] Figure 19 This is a diagram illustrating the change in test pattern 60 when nozzles 23 and 24 have a positional offset in the Y direction. Figure 19 This indicates that the ink droplet position of printhead 24 has shifted to the Y2 side relative to the ink droplet position of printhead 23.

[0275] As the ink droplet position of the printhead 24 shifts towards the Y2 side, the second line 62 formed by the printhead 24 is displaced towards the Y2 side.

[0276] Therefore, as Figure 19 As shown, in the overlapping portion 630, the second line 62 is close to or overlaps with the first line 61. The gap D4 of the first line 61 is not filled by the second line 62 and is visually recognized as a portion where no ink has been sprayed. In other words, the overlapping portion 630 becomes a state of uneven spraying and cannot be visually recognized as such. Figure 19 A full coat as shown.

[0277] Users compared the fully coated sample block 660 (reference) Figure 17 By observing the state of the overlapping portion 630, it is possible to determine whether the ink droplet positions of the printheads 23 and 24 have shifted in the Y direction.

[0278] like Figure 19 As shown, because the ink droplet position of printhead 24 shifts towards the Y2 side, the second reference line 65 formed by printhead 24 also shifts towards the Y2 side in the same way as the second line 62. Therefore, the positions of the first reference line 64 and the second reference line 65 in the Y direction shift, and the second reference line 65 no longer overlaps with the first reference line 64, but is located closer to the Y2 side than the first reference line 64. By comparing the first reference line 64 and the second reference line 65, the user can determine that the ink droplet position of printhead 24 has shifted towards the Y2 side relative to the ink droplet position of printhead 23. Furthermore, by observing the amount of shift of the second reference line 65 relative to the first reference line 64, the approximate amount of shift in the ink droplet position of printhead 24 can be determined.

[0279] In addition, such as Figure 17 As shown, in the test pattern 60, a first line portion 610 without an overlapping portion 630 is provided. When all the first line portions 610 have overlapping portions, it may be difficult to distinguish the first line portion 610 and the second line portion 620 when the orientation of the medium M changes, etc. The user can distinguish the first line portion 610 and the second line portion 620 based on the first line portion 610 without an overlapping portion 630.

[0280] Although the illustration is omitted, controller 27 (see reference) Figure 1 For example, in calibration mode, it accepts input of calibration values ​​for calibrating the ink droplet positions of nozzles 241-248 of printhead 24. Controller 27, for example, controls the operation panel 26 (see reference 26). Figure 1The input section displays the correction value. The user inputs a correction value corresponding to the offset direction and amount of the ink dot position of the printhead 24 as confirmed by the test pattern 60. At this time, the user may input the correction value only for the nozzle section 244 of the printhead 24. Alternatively, the same correction value may be input for all nozzle sections 241 to 248 of the printhead 24.

[0281] The user repeatedly prints the test pattern 60 and inputs the correction values ​​until the overlap 630 (refer to...). Figure 19 It becomes the same fully coated state as sample block 660 (refer to...) Figure 17 )until.

[0282] This allows for the correction of the positional offset of printheads 23 and 24 in the Y direction. During printing, the controller 27 reflects the correction value in the ink dot position of printhead 24 in the print data, thereby controlling the movement of printhead 24.

[0283] Alternatively, a displacement mechanism in the Y direction can be provided on the nozzle 24 to correct the positional offset between the nozzle 23 and the nozzle 24 in the Y direction.

[0284] If the positional offset correction of nozzles 23 and 24 in the Y direction is completed, then test pattern 70 is used to perform positional offset correction of nozzles 23 and 24 in the X direction. Figure 8 Step 3).

[0285] Test pattern 70 is formed using the nozzle portion 234 of nozzle 23 and the nozzle portion 244 of nozzle 24, just like test pattern 60.

[0286] Figure 20 This is a diagram of test pattern 70 used for position offset correction in the X direction.

[0287] Figure 20 The X, Y, and Z directions indicate the orientation of the medium M when it is located on the platform 21. Additionally, Figure 20 The test pattern 70 represents the result formed when the ink dots at nozzles 234 and 244 are at the same position.

[0288] like Figure 20 As shown, the test pattern 70 consists of three shapes: a rectangular block 71, a trapezoidal block 81, and a line 91.

[0289] Each pattern in test pattern 70 intersects with a line segment HL parallel to the Y direction. The area on the X2 side is formed by the nozzle portion 234 of nozzle 23, and the area on the X1 side is formed by the nozzle portion 244 of nozzle 24. Furthermore, the intersections located on line segment HL are actually not very noticeable, but... Figure 20 For ease of understanding, thick lines are used to represent characters.

[0290] In addition, although test pattern 70 was formed entirely using magenta ink, Figure 20 In order to make it easier to understand, different shaded lines are marked on the areas formed by nozzle part 234 and nozzle part 244 respectively.

[0291] Figure 21 yes Figure 20 An enlarged view of the portion enclosed by box A.

[0292] Block 71 has a region 71A (first region) formed by nozzle 23 on the X2 side of line segment HL. Block 71 has a region 71B (second region) formed by nozzle 24 on the X1 side of line segment HL.

[0293] like Figure 21 As shown, at the junction of regions 71A and 71B, there is an uneven surface formed in the form of a line segment HL.

[0294] The concave and convex shapes are formed by a linear portion 72 (first linear portion) located on the X2 side of line segment HL, a linear portion 73 (second linear portion) located on the X1 side of line segment HL, and a linear portion 74 (third linear portion) connecting the ends of linear portions 72 and 73 to each other.

[0295] Linear portions 72 and 73 extend parallel to line segment HL. Linear portions 72 and 73 are arranged alternately in the Y direction. Linear portion 74 extends in a direction orthogonal to line segment HL. When viewed from above, at the boundary of regions 71A and 71B, rectangular convex and concave shapes are continuously arranged in the Y direction.

[0296] Linear portions 72, 73, and 74 are formed by the overlap of ink ejected from nozzle portion 234 of printhead 23 and ink ejected from nozzle portion 244 of printhead 24. That is, linear portions 72, 73, and 74 are formed by the overlap of the end portion on the X1 side of region 71A and the end portion on the X2 side of region 71B.

[0297] Furthermore, when the ink dots of printheads 23 and 24 are in the same position, the concave and convex shape of the line segment HL is difficult to be visually identified by the naked eye.

[0298] like Figure 20 As shown, the trapezoidal block 81, with line segment HL as its boundary, has a region 81A on the X2 side formed by nozzle 23 and a region 81B on the X1 side formed by nozzle 24. Block 81 has an end 82 on the Y1 side and an end 83 on the Y2 side. End 82 is a straight line extending parallel to the X direction. End 83 is an oblique line inclined relative to the X direction. End 83 inclines towards the Y2 side as it moves from the X2 side towards the X1 side.

[0299] Line 91 is a straight line extending along the X direction. Line 91 is bounded by line segment HL and has a region 91A on the X2 side formed by nozzle 23 and a region 91B on the X1 side formed by nozzle 24.

[0300] Figure 22 This is a diagram illustrating the change in test pattern 70 when the positions of nozzles 23 and 24 are offset in the X direction. Figure 22 Show the line segment HL around block 71. Figure 22 (a) indicates the case where the ink droplet position of printhead 24 is shifted to the X1 side of the ink droplet position of printhead 23. Figure 22 (b) indicates the case where the ink droplet position of printhead 24 is shifted to the X2 side of the ink droplet position of printhead 23.

[0301] like Figure 22 As shown in (a), when the printhead 24 is offset in the X1 direction, region 71B of block 71 is displaced entirely away from region 71A. Consequently, the ends of region 71A and region 71B do not overlap, creating a gap at the boundary between regions 71A and 71B. Here, the gap refers to the portion where no ink is ejected.

[0302] Specifically, a gap 75A is formed between the linear portion 72 of region 71A and the linear portion 72 of region 71B. A gap 75B is formed between the linear portion 73 of region 71A and the linear portion 73 of region 71B. The gaps 75A on the X2 side and the gaps 75B on the X1 side of line segment HL are alternately arranged and continuously formed in the Y direction.

[0303] With gaps 75A and 75B formed in block 71, the user can detect when the ink droplet position of printhead 24 is offset to the X1 side relative to the ink droplet position of printhead 23. The user can correct the positional offset of printhead 24 in the X direction by using a displacement mechanism (not shown) to move printhead 24 to the X2 side.

[0304] like Figure 22 As shown in (b), when the nozzle 24 is offset to the X2 side in the X direction, region 71B of block 71 is displaced as a whole towards region 71A. As a result, the end of region 71B is displaced to the X2 side of the end of region 71A and overlaps with region 71A.

[0305] Specifically, the linear portion 72 of region 71B overlaps with region 71A to form a high-concentration region 76A. The linear portion 73 of region 71B overlaps with region 71A to form a high-concentration region 76B. The high-concentration regions 76A and 76B are regions where the color appears darker due to ink overlap.

[0306] The high-concentration region 76A on the X1 side and the high-concentration region 76B on the X2 side of line segment HL are arranged alternately and continuously in the Y direction.

[0307] When high-concentration regions 76A and 76B are formed in block 71, the user can detect that the ink droplet position of printhead 24 has shifted to the X2 side relative to the ink droplet position of printhead 23. The user can adjust the positional shift of printhead 24 by using a displacement mechanism (not shown) to move printhead 24 to the X1 side.

[0308] Although the illustration is omitted, when the ink droplet position of printhead 24 shifts in the X direction, in Figure 23 Block 81 and line 91 shown will also create gaps or high-concentration areas. Users can also determine the positional offset of nozzles 23 and 24 in the X direction based on block 81 and line 91.

[0309] Here, with a small positional offset in the X direction of the printheads 23 and 24, the gaps 75A and 75B, or the high-concentration regions 76A and 76B, are small, making individual units sometimes difficult to visually identify. In particular, since the nozzles 234 and 244 eject ink of the same color, it is difficult to visually identify the high-concentration regions. In block 71, the gaps 75A and 75B, or the high-concentration regions 76A and 76B, are formed in a manner that offsets their positions towards the X1 and X2 sides of the line segment HL, thus appearing as an alternating continuous pattern in the Y direction. Therefore, the gaps 75A and 75B, or the high-concentration regions 76A and 76B, are easily visually identified as a continuous pattern.

[0310] Furthermore, although the shape of the positional offset of the nozzle 24 in the X direction is explained here based on the test pattern 70, the positional offset in the Y direction or the tilt of the nozzles 23 and 24 can also be determined based on the test pattern 70.

[0311] Figure 23 This is a test pattern 70 showing the positional offset of nozzles 23 and 24 in the Y direction.

[0312] Figure 23 This is a test pattern 70 showing a situation where the ink droplet position of the nozzle portion 244 of the printhead 24 has shifted to the Y1 side.

[0313] In block 71, due to the offset of region 71B towards the Y1 side, the linear portion 74 of region 71A is offset from the linear portion 74 of region 71B in the Y direction. As a result, a high-concentration region is formed in the linear portion 74 on the Y1 side, and a gap is generated in the linear portion 74 on the Y2 side.

[0314] In block 81, due to the offset of region 81B towards the Y1 side, the ends 82 and 83 in the Y direction create a step at the location traversed by line segment HL. In particular, since end 83 is a beveled edge, the step is easily visually identifiable.

[0315] In line 91, because region 91B also shifts towards the Y1 side, a step is created at the location traversed by line segment HL. Users can use these phenomena to determine the offset of the ink dot position in test pattern 70.

[0316] Furthermore, although the illustration is omitted, if either of the nozzles 23 or 24 is tilted, the same applies: region 91A or region 91B of line 91 will be tilted, and line 91 will not be a continuous straight line in the X direction. The user can determine the tilt of nozzles 23 and 24 based on this phenomenon.

[0317] If these phenomena are confirmed in test pattern 70, there is a possibility that the tilt correction or ink dot position correction is insufficient, so it is possible to return to the adjustment using test patterns 50 and 60.

[0318] Furthermore, in the above example, an example was described where linear portions 72 (first linear portion), 73 (second linear portion), and 74 (third linear portion) were formed as the ends of regions 71A and 71B of block 71. However, even using only linear portions 72 to 74, the positional offset of printheads 23 and 24 can be controlled. In test pattern 70, printheads 23 and 24 can also be used to print only the raised and recessed shapes formed by linear portions 72 to 74, without printing the entire block 71.

[0319] If the position offset correction in the X direction based on test pattern 70 is completed, such as Figure 8 As shown, the calibration process can be ended.

[0320] Alternatively, the test pattern 60 can be formed using combinations of nozzles other than the nozzle portions 234 and 244 of the nozzles 23 and 24. Even if the positional offset in the Y direction of the reference nozzle portions 234 and 244 is corrected, slight positional offsets in the Y direction may still exist in other combinations of nozzle portions. By using other combinations of nozzle portions to form the test pattern 60, more accurate positional correction can be achieved.

[0321] Furthermore, if tilt correction based on test pattern 50 has been completed and position offset correction in the Y direction or X direction has been performed using test patterns 60 and 70, tilt correction based on test pattern 50 can be performed again. The correction process can be terminated when no correction is required for any of the test patterns.

[0322] In this way, by adjusting using test patterns 50, 60, and 70, the printing device 1 can print with the ink droplet positions of the printheads 23 and 24 aligned, thereby improving print quality. Furthermore, the "aligned ink droplet positions (ink landing positions) of the printheads 23 and 24" includes not only a completely aligned state, but also a state with a slight deviation that does not affect print quality.

[0323] In this embodiment, an example is described where test patterns 50, 60, and 70 are printed on medium M respectively, but this is not a limitation. Test patterns 50, 60, and 70 may also be printed on the same medium M.

[0324] As described above, the test pattern 50 in the embodiment has, for example, the following structure.

[0325] (1) The test pattern 50 is printed on the medium M by spraying ink from the printheads 23 and 24 (inkjet heads) which have multiple nozzles 231 to 238 and 241 to 248.

[0326] Regions 51A and 52A of test pattern 50 include:

[0327] Baseline 530 (first baseline) is formed along the Y direction (first direction, main scanning direction) using ink ejected from the nozzle portions 231, 241 (first nozzle portions) of printheads 23, 24; and

[0328] Blocks 540 (first block) and 550 (second block) are formed by ink ejected from nozzles 235 and 245 (second nozzles) of printheads 23 and 24, which are spaced apart from the first nozzles 231 and 241 in the Y direction.

[0329] Block 540 is formed on the X1 side (one side) of the baseline 530 in the X direction (second direction, sub-scanning direction) orthogonal to the Y direction, and block 550 is formed on the X2 side (the other side).

[0330] When nozzles 23 and 24 are tilted, baseline 530 is relatively displaced relative to blocks 540 and 550, resulting in a difference between the distance between baseline 530 and block 540 and the distance between baseline 530 and block 550. By confirming this difference in distance, the user can determine the tilt of nozzles 23 and 24.

[0331] (2) In the test pattern 50, multiple baselines 530 are formed at open intervals in the X direction.

[0332] Multiple blocks 540 are arranged along the X direction, each located on the X1 side of a plurality of baselines 530.

[0333] Multiple blocks 550 are arranged along the X direction, each located on the X2 side of a plurality of baselines 530.

[0334] Multiple blocks 540 and multiple blocks 550 are arranged in a staggered manner in the X direction without overlapping.

[0335] The set of blocks 540 forms arrow 54 (Figure 1). The set of blocks 550 forms arrow 55 (Figure 2).

[0336] (3) The nozzles 23 and 24 are configured to rotate around an inclined axis TA that extends along the Z direction (the third direction) which is orthogonal to the X and Y directions.

[0337] (4) Arrow 54, which is the first graphic, and arrow 55, which is the second graphic, are graphics with different appearances. Depending on the rotation direction of the tilt axis TA of nozzles 23 and 24, either arrow 54 or arrow 55 is visually recognized as a graphic with a denser appearance than the other.

[0338] In human vision, the following illusion occurs: even with the same line pattern, if the lines are closer together, the density appears lighter, and if the lines are farther apart, the density appears darker. Arrows 54 and 55, formed by the sets of blocks 540 and 550, are visually perceived as having different densities depending on the tilt direction of nozzles 23 and 24 (the direction of rotation of the tilt axis). Therefore, the user can visually determine the tilt of nozzles 23 and 24 based on the test pattern 50. Since no magnifying glass or other tools are needed, convenience is improved.

[0339] Furthermore, the first and second graphics only need to have different appearances and are not limited to arrows 54 and 55. The first and second graphics can also be graphics other than arrows, such as text.

[0340] (5) Arrow 54 (Figure 1) and arrow 55 (Figure 2) are marks indicating the rotation direction of the tilt axis TA, respectively.

[0341] When the printing device 1 is equipped with a knob 225 that is linked to the rotation mechanism of the tilt axis TA, the first and second graphics can be set as arrows 54 and 55 indicating the rotation direction of the knob 225. Thus, the user can easily determine, based on the test pattern 50, which direction to turn the knob to adjust the tilt of the printheads 23 and 24. That is, the user can adjust the tilt of the printheads 23 and 24 by turning the knob 225 in the direction indicated by the darker arrow in the test pattern 50.

[0342] Furthermore, in the above-described embodiment, examples of counterclockwise arrow 54 and clockwise arrow 55 indicating the rotation direction of the tilt axis TA are shown as markers, but this is not a limitation. For example, the markers indicating the rotation direction of the tilt axis TA could be written as words such as "counterclockwise" and "clockwise". Alternatively, words meaning "counterclockwise" and "clockwise", such as "CCW" and "CW", could be used as markers indicating the rotation direction of the tilt axis TA.

[0343] Furthermore, in the above embodiment, an example was described where the tilt of the nozzles 23 and 24 was adjusted by rotating the knob 225, which is linked to the tilting mechanism; however, this embodiment is not limited to this configuration. For example, the knob 225 may not be used, and the user may directly move the nozzles 23 and 24 forward or backward, thereby rotating the tilting axis TA to adjust the tilt. In this case, the marking indicating the rotation direction of the tilting axis TA may be a straight arrow indicating the direction of movement of the nozzles 23 and 24 forward or backward.

[0344] (6) The nozzle section 231 (first nozzle section) and the nozzle section 235 (second nozzle section) of the printing device 1 are each composed of a plurality of nozzles N arranged at a certain interval along the X direction.

[0345] The nozzles N1a, N1b, N1c, N1d, N1e... of nozzle section 231 and the nozzles N5a, N5b, N5c, N5d, N5e, N5f... of nozzle section 235 are arranged alternately in the X direction.

[0346] The baseline 530 is formed by the nozzles N1a, N1c, and N1e (first nozzle) of the nozzle section 231.

[0347] Block 550 is formed by nozzles N5a, N5c, and N5e (the third nozzle) that are adjacent to nozzles N1a, N1c, and N1e on the X2 side in the X direction of nozzle section 235.

[0348] Block 540 is formed by nozzles N5b, N5d, and N5f (second nozzles) that are adjacent to nozzles N1a, N1c, and N1e on the X1 side in the X direction of nozzle section 235.

[0349] In this embodiment, by using nozzle sections 231 and 235 with nozzles having different phases in the X direction, combinations P1, P2, and P3 of baseline 530 and blocks 540 and 550 are formed with the width of three ink dots in the X direction. As a result, the line density in the test pattern 50 becomes higher, and even a slight tilt of the printheads 23 and 24 will produce a difference in the density of arrows 54 and 55, thus enabling high-precision tilt correction.

[0350] (7) The regions 51B and 52B of the test pattern 50 include baseline 530 (second baseline), block 540 (third block), and block 550 (fourth block).

[0351] The baseline 530 (second baseline) is formed along the Y direction by ink ejected from the nozzle section 234 and nozzle section 244 (third nozzle section) of the printheads 23 and 24.

[0352] Block 540 (the third block) is formed using ink ejected from nozzles 238 and 248 (the fourth nozzles) of printheads 23 and 24, which are spaced apart from nozzles 234 and 244 in the Y direction. Block 540 is formed adjacent to baseline 530 on the X1 side (one side) of baseline 530 in the X direction.

[0353] Block 550 (the fourth block) is formed using ink ejected from nozzles 238 and 248. Block 550 is formed adjacent to baseline 530 on the X2 side (the other side) of baseline 530 in the X direction. Block 550 and block 540 are arranged with a gap in the Y direction.

[0354] The distance D3 in the Y direction between the nozzle portions 234, 244 and the nozzle portions 238, 248 forming regions 51B and 52B is longer than the distance D2 in the Y direction between the nozzle portions 231, 241 and the nozzle portions 235, 245 forming regions 51A and 52A.

[0355] Regions 51A and 52A for coarse adjustment are formed by nozzle sections with shorter distances between them, while regions 52A and 52B for fine adjustment are formed by nozzle sections with longer distances between them. Therefore, in the initial stage when the nozzles 23 and 24 are tilted significantly, the difference in concentration of arrows 54 and 55 is easily observed in regions 51A and 52A for coarse adjustment. In the stage where the tilt of the nozzles 23 and 24 has been corrected and the tilt has decreased, the difference in concentration of arrows 54 and 55 is easily observed in regions 51B and 52B for fine adjustment.

[0356] Since the test pattern 50 includes regions 51A and 52A for coarse adjustment and regions 51B and 52B for fine adjustment, the user can compare regions 51A and 52A and regions 51B and 52B in the test pattern 50, thus enabling a smooth transition from coarse adjustment to fine adjustment.

[0357] Furthermore, the areas 51A and 52A for coarse adjustment and the areas 51B and 52B for fine adjustment can also be printed on different media M. Alternatively, the tilt of the printheads 23 and 24 can be corrected using only the areas 51A and 52A for coarse adjustment or the areas 51B and 52B for fine adjustment.

[0358] The same effect can also be obtained in the printing method and printing apparatus 1 for printing the above-mentioned test pattern 50.

[0359] (Variation Example 1)

[0360] Figure 24 This is a diagram showing the method of forming the test pattern 50A of variation 1.

[0361] In one embodiment, an example is described of forming a test pattern 50 using nozzle portions with nozzles arranged at phase offsets in the X direction. In a modified example 1, an example is described of forming a test pattern 50A using nozzle portions with nozzles arranged at the same phase in the X direction.

[0362] Figure 24 This illustrates an example where the nozzles of nozzle sections 231A and 235A are arranged in the same phase. The same applies to other nozzle sections; any combination of nozzle sections in the same phase can be formed in the same way.

[0363] like Figure 24 As shown, the nozzles N1a, N1b, N1c, N1d, N1e, N1f, N1g... of the nozzle section 231A are arranged at intervals D from the X2 side toward the X1 side in the X direction.

[0364] The nozzles N5a, N5b, N5c, N5d, N5e, N5f, N5g... of the nozzle section 235A are arranged at intervals D from the X2 side toward the X1 side in the X direction.

[0365] Each nozzle of nozzle section 231A and each nozzle of nozzle section 235A are arranged at the same position in the X direction. That is, the nozzles of nozzle section 231A and nozzle section 235A are arranged in the same phase in the X direction.

[0366] exist Figure 24 The diagram shows two combinations P4 and P5 of baseline 530 and blocks 540 and 550. Baseline 530 is formed by nozzle portion 231A which is farther from the tilt axis TA, and blocks 540 and 550 are formed by nozzles of nozzle portion 235A which is closer to the tilt axis TA.

[0367] In assembly P4, baseline 530 is formed by nozzle N1b of nozzle section 231A. Block 540 is formed by nozzle N5c on the X1 side of nozzle N1b. Block 550 is formed by nozzle N5a on the X2 side of nozzle N1b.

[0368] Do not use nozzle N5b, which has the same phase as nozzle N1b. Do not use nozzles N1a and N1c, which have the same phase as nozzles N5a and N5c.

[0369] Blocks 540 and 550 are formed with a gap in the X direction corresponding to one ink dot, relative to baseline 530. Combination P4 is formed in the X direction with a width corresponding to five ink dots.

[0370] Between combination P4 and combination P5, there is a gap in the X direction corresponding to the three ink dots. Therefore, nozzles N1d and N5d are not used.

[0371] In assembly P5, baseline 530 is formed by nozzle N1f of nozzle section 231A. Block 540 is formed by nozzle N5g on the X1 side of nozzle N1f. Block 550 is formed by nozzle N5e on the X2 side of nozzle N1f.

[0372] Nozzle N5f, which has the same phase as nozzle N1f, is not used. Nozzles N1e and N1g, which have the same phase as nozzles N5e and N5g, are not used. Combination P5 is also formed in the X direction with a width corresponding to 5 ink dots, just like combination P4.

[0373] Thus, in Modified Example 1, similarly to the Embodiment 1, a nozzle forming block 540 is formed on one side (X1 side) of the nozzle that forms the baseline 530 in the X direction, and a nozzle forming block 550 is formed on the other side (X2 side).

[0374] However, in Modification 1, by using nozzles arranged in nozzle sections of the same phase, a combination of baseline 530 and blocks 540 and 550 is formed in the X direction with a wider width corresponding to 5 ink dots. Furthermore, between combinations P4 and P5, a gap corresponding to 3 ink dots is provided in the X direction. As described above, in this embodiment, a combination of baseline 530 and blocks 540 and 550 is formed with a width corresponding to 3 ink dots in the X direction, and a gap corresponding to 1 ink dot is provided in the X direction between combinations P1 to P3 (see reference). Figure 11 ).

[0375] That is, compared with the test pattern 50 of the embodiment, the distance in the X direction between the baseline 530 and the blocks 540 and 550 in the test pattern 50A of Modified Example 1 is greater. The line density of the test pattern 50A is less than that of the test pattern 50. That is, the effect of the tilt of the nozzles 23 and 24 on the test pattern 50A is less than the effect of the tilt of the nozzles 23 and 24 on the test pattern 50. Therefore, the test pattern 50A can be used, for example, for coarse adjustment when the tilt of the nozzles 23 and 24 is large.

[0376] The printing device 1 can also print the test pattern 50A of the modified example for coarse adjustment during the stage of larger tilt of the nozzles 23 and 24, and print the test pattern 50 of the embodiment for fine adjustment during the stage of smaller tilt.

[0377] As described above, the test pattern 50A illustrated in Modification 1 has the following structure.

[0378] (8) The nozzles N1a, N1b, N1c, N1d, N1e, N1f, N1g... of the nozzle section 231A (first nozzle section) of the printing device 1 and the nozzles N5a, N5b, N5c, N5d, N5e, N5f, N5g... of the nozzle section 235A (second nozzle section) are arranged in the same position in the X direction.

[0379] The baseline 530 is formed by the nozzles N1b and N1f (first nozzle) of the nozzle section 231A.

[0380] Block 540 (the first block) is formed by nozzles N5c and N5g (the second nozzles) that are adjacent to nozzles N1b and N1f on the X1 side (one side) of nozzle section 235A in the X direction.

[0381] Block 550 (the second block) is formed by nozzles N5a and N5e (the third nozzles) that are adjacent to nozzles N1b and N1f on the X2 side (the other side) of nozzle section 235A in the X direction.

[0382] Test pattern 50A can also be formed by using a combination of nozzles arranged in the same phase. Since the test pattern 50A formed by the combination of nozzles in the same phase has a low line density, it is easy to show the difference in density of arrows 54 and 55 even when the nozzles 23 and 24 are tilted significantly, so it is preferred for coarse adjustment.

[0383] Furthermore, as described above, the test pattern 60 in the embodiment has, for example, the following structure.

[0384] (1) The test pattern 60 is printed on the medium M using ink ejected from the printhead 23 (first printhead) and the printhead 24 (second printhead).

[0385] The test pattern 60 has a first line 61 and a second line 62 printed alternately in the Y direction (first direction).

[0386] The first line 61 is formed by ink ejected from multiple nozzles N of the printhead 23 arranged in the X direction (second direction) orthogonal to the Y direction.

[0387] The second line 62 is formed by ink ejected from multiple nozzles N arranged in the X direction by the printhead 24.

[0388] When the ink droplet positions of printheads 23 and 24 are offset in the Y direction, the positional relationship between line 1 61 and line 2 62 changes in test pattern 60. The user can determine the offset in the Y direction of the ink droplet positions of printheads 23 and 24 based on the positional relationship between line 1 61 and line 2 62.

[0389] (2) The test pattern 60 has an overlap 630 when the first line 61 and the second line 62 are viewed from the Y direction.

[0390] When the landing position (ink drop position) of the ink ejected from the nozzle N of the printhead 23 and the landing position (ink drop position) of the ink ejected from the nozzle N of the printhead 24 are consistent in the X direction, the overlapping portion 630 is visually recognized as a filled area.

[0391] When the offset of the ink droplet positions of printheads 23 and 24 is small, it is difficult to visually confirm the change in the positional relationship between line 1 61 and line 2 62. By arranging line 2 62 at intervals D4 that fill line 1 61, the overlapping area 630 is visually recognized as a filled area when the ink droplet positions of printheads 23 and 24 are consistent. That is, if the ink droplet positions of printheads 23 and 24 are offset in the Y direction, uneven spraying occurs in the overlapping area 630. The user can easily perceive the positional offset with the naked eye.

[0392] (3) The test pattern 60 also has a first baseline 64 and a second baseline 65.

[0393] The first baseline 64 is formed using ink ejected from the nozzle N of the printhead 23.

[0394] The second baseline 65 is formed using ink ejected from nozzle N of printhead 24.

[0395] When the landing position (ink drop position) of the ink ejected from the nozzle N of the printhead 23 and the landing position (ink drop position) of the ink ejected from the nozzle N of the printhead 24 are consistent in the Y direction, the first reference line 64 and the second reference line 65 have an overlapping area.

[0396] When the ink drop positions of printhead 23 and printhead 24 are offset in the Y direction, the second reference line 65 and the first reference line 64 do not overlap, but are offset to the Y1 side or Y2 side of the first reference line 64 according to the offset direction of printhead 24.

[0397] By setting the first reference line 64 and the second reference line 65 separately from the densely overlapping part 630, the offset direction of the nozzle 24 can be easily determined.

[0398] (4) In block 71 of test pattern 70 (pattern), the linear portion 72 (first linear portion) located on the X2 side (one side) of the line segment HL (imaginary line) along the Y direction and the linear portion 73 (second linear portion) located on the X1 side (the other side) are alternately arranged in the Y direction.

[0399] Linear portions 72 and 73 are formed by the overlap of ink ejected from nozzle N of printhead 23 and ink ejected from nozzle N of printhead 24.

[0400] Even when the ink droplet positions of printheads 23 and 24 are offset in the X direction, the line portions 72 and 73 formed by printheads 23 and 24 do not overlap, but are printed with their positions offset in the X direction. Even if the positional offset in the X direction is small, the positional offset is easily noticeable because the line portions 72 and 73 are arranged alternately in the Y direction. The user can easily grasp the offset of the ink droplet positions of printheads 23 and 24 in the X direction by visually observing the test pattern 70.

[0401] (5) Block 71 of test pattern 70 has region 71A (first region) and region 71B (second region). Region 71A is located on the X2 side (one side) of line segment HL and is filled with ink ejected from nozzle N of printhead 23. Region 71B is located on the X1 side (the other side) of line segment HL and is filled with ink ejected from nozzle N of printhead 24.

[0402] Linear portions 72 and 73 are formed from the opposite ends of regions 71A and 71B.

[0403] (6) When the landing position (ink drop position) of the ink ejected from the nozzle N of the printhead 23 and the landing position (ink drop position) of the ink ejected from the nozzle N of the printhead 24 are inconsistent in the X direction, gaps 75A and 75B or high-concentration regions 76A and 76B are generated at the boundary between region 71A and region 71B.

[0404] The gaps 75A, 75B or the high-concentration areas 76A, 76B that form at the boundary of the filled areas 71A, 71B are easily noticeable, making it easy for users to determine the positional offset based on the test pattern 70. Furthermore, the gaps 75A, 75B or the high-concentration areas 76A, 76B appear to alternate continuously along the linear portions 72 and 73 in the Y direction, making them easier for users to visually identify.

[0405] (7) In the test pattern 70, the linear portion 72 and the linear portion 73 are parallel to the line segment HL. The ends of the linear portion 72 and the linear portion 73 are connected by the linear portion 74 (the third linear portion) which is orthogonal to the line segment HL.

[0406] The linear portion 74 is formed by the overlap of ink ejected from the nozzle N of the printhead 23 and ink ejected from the nozzle N of the printhead 24.

[0407] By utilizing linear portions 72, 73, and 74, an uneven shape is formed at the boundary between the first and second regions. This uneven shape is easily noticeable, making it easy for the user to determine the positional offset of the nozzles 23 and 24. Furthermore, when the nozzles 23 and 24 are offset in the Y direction, gaps 75A and 75B or high-concentration regions 76A and 76B are generated along the linear portion 74. Therefore, the user can also determine the positional offset of the nozzles 23 and 24 in the Y direction based on the test pattern 70.

[0408] The same effect can be obtained in the printing method and printing device for printing the test patterns 60 and 70 mentioned above.

[0409] This invention is not limited to the above-described embodiments and can be appropriately modified within the scope of the technical concept of this invention.

[0410] (Postscript)

[0411] (A) A test pattern printed on a medium using ink ejected from a first inkjet head and a second inkjet head, characterized in that,

[0412] Using an imaginary line along a first direction as a reference, the test pattern has: a first linear portion located on one side of the imaginary line in a second direction (orthogonal to the first direction); and a second linear portion located on the other side of the imaginary line in the second direction, wherein the first linear portion and the second linear portion are printed alternately in the first direction.

[0413] The first linear portion and the second linear portion are formed by the overlap of ink ejected from the nozzle of the first inkjet head and ink ejected from the nozzle of the second inkjet head.

[0414] (B) A method for printing a test pattern, wherein the test pattern is printed on a medium by ejecting ink from a first inkjet head and a second inkjet head, characterized in that,

[0415] Using an imaginary line along a first direction as a reference, a first linear portion located on a side further along the second direction (orthogonal to the first direction) than the imaginary line and a second linear portion located on the other side further along the second direction than the imaginary line are alternately printed in the first direction.

[0416] The ink ejected from the nozzle of the first inkjet head overlaps with the ink ejected from the nozzle of the second inkjet head to form the first linear portion and the second linear portion.

[0417] (C) A test pattern printing apparatus, wherein ink is ejected from a first inkjet head and a second inkjet head to print the test pattern onto a medium, characterized in that,

[0418] Using an imaginary line along a first direction as a reference, a first linear portion located on a side further along the second direction (orthogonal to the first direction) than the imaginary line and a second linear portion located on the other side further along the second direction than the imaginary line are printed alternately in the first direction.

[0419] The ink ejected from the nozzle of the first inkjet head overlaps with the ink ejected from the nozzle of the second inkjet head to form the first linear portion and the second linear portion.

[0420] Explanation of reference numerals in the attached figures

[0421] 1. Printing unit; 2. Main body; 3. Stand; 21. Table; 22. Printhead; 23. Inkjet head (first inkjet head); 231. Nozzle section (first nozzle section); 234. Nozzle section (third nozzle section); 235. Nozzle section (second nozzle section); 238. Nozzle section (fourth nozzle section); 24. Inkjet head (second inkjet head); 241. Nozzle section (first nozzle section); 244. Nozzle section (third nozzle section); 245. Nozzle section (second nozzle section) 248. Nozzle section (4th nozzle section); 225. Tilt adjustment knob; 226. Displacement adjustment knob; 25. Ultraviolet irradiation section; 26. Operation panel; 27. Controller; 28. Ink supply mechanism; 281. Ink bottle; 282. Ink supply passage; 29. ​​Moving mechanism; 291. Carriage; 292. Guide rail; 30. Feed mechanism; 50. Test pattern; 51A, 51B, 52A, 52B, Area; 53. Substrate; 530. Baseline; 54, Arrow (Figure 1); 540, Block (Block 1); 55, Arrow (Figure 2); 550, Block (Block 2); 60, Test Pattern; 610, First Line Section; 61, First Line; 620, Second Line Section; 62, Second Line; 630, Overlapping Section; 64, First Baseline; 65, Second Baseline; 660, Sample Block; 70, Test Pattern; 71, Block; 71A, Region (Region 1); 71B, Region (Region 2) ) ; 72, Linear section (first linear section); 73, Linear section (second linear section); 74, Linear section (third linear section); 75A, 75B, Gap; 76A, 76B, High concentration region; 81, Block; 81A, 81B, Region; 82, 83, End; 91, Line; 91A, 91B, Region; TA, Tilt axis; HL, Line segment (imaginary line); M, Medium; Y, Main scanning direction (first direction); X, Sub-scanning direction (second direction).

Claims

1. A test pattern, wherein the test pattern is printed on a medium by ejecting ink from an inkjet head having a plurality of nozzles, characterized in that, The test pattern includes: A first baseline is formed along a first direction using ink ejected from a first nozzle portion of the inkjet head; and The first and second blocks are formed using ink ejected from a second nozzle portion of the inkjet head, which is disposed at an open interval from the first nozzle portion in the first direction. The first block is formed on one side of the first baseline in a second direction orthogonal to the first direction, and the second block is formed on the other side of the first baseline in the second direction. Multiple first baselines are formed at open intervals in the second direction. Multiple first blocks are arranged along the second direction, each located on one side of a plurality of first baselines. Multiple second blocks are arranged along the second direction, each located on the other side of one of the multiple first baselines. The plurality of said first blocks and the plurality of said second blocks are arranged in a staggered manner in the second direction without overlapping. The set of the first blocks forms the first graphic, and the set of the second blocks forms the second graphic. The inkjet head is configured to rotate about an inclined axis extending along a third direction orthogonal to the first and second directions. The first and second figures each contain markings indicating the rotation direction of the tilt axis.

2. The test pattern according to claim 1, wherein, The first graphic and the second graphic are graphics with different appearances. Depending on the rotation direction of the tilt axis, either the first graphic or the second graphic is visually perceived as a darker graphic than the other.

3. The test pattern according to claim 1 or 2, characterized in that, The first nozzle section and the second nozzle section are each composed of a plurality of nozzles arranged at certain intervals along the second direction. The nozzles of the first nozzle section and the nozzles of the second nozzle section are arranged alternately in the second direction. The first baseline is formed by the first nozzle of the first nozzle portion. The first block is formed by a second nozzle adjacent to the first nozzle on one side of the second nozzle portion in the second direction. The second block is formed by a third nozzle adjacent to the first nozzle on the other side of the second nozzle portion in the second direction.

4. The test pattern according to claim 1 or 2, characterized in that, The first nozzle section and the second nozzle section are composed of a plurality of nozzles arranged at certain intervals along the second direction. The nozzles of the first nozzle section and the second nozzle section are positioned at the same location in the second direction. The first baseline is formed by the first nozzle of the first nozzle portion. The first block is formed by a second nozzle adjacent to the first nozzle on one side of the second nozzle portion in the second direction. The second block is formed by a third nozzle adjacent to the first nozzle on the other side of the second nozzle portion in the second direction.

5. The test pattern according to claim 1 or 2, characterized in that, The test pattern includes: The second baseline is formed along the first direction using ink ejected from the third nozzle portion of the inkjet head; The third block is formed by ink ejected from a fourth nozzle portion of the inkjet head, which is spaced apart from the third nozzle portion in the first direction. This third block is formed adjacent to the second baseline on one side of the second baseline in the second direction. The fourth block, formed using ink ejected from the fourth nozzle, is formed adjacent to the second baseline on the other side of the second baseline in the second direction, and is disposed at a distance from the third block in the first direction. The distance in the first direction between the third nozzle portion and the fourth nozzle portion is longer than the distance in the first direction between the first nozzle portion and the second nozzle portion.

6. A method for printing a test pattern, wherein the test pattern is printed on the medium by ejecting ink from an inkjet head having multiple nozzles, characterized in that... Ink is ejected from the first nozzle portion of the inkjet head, thereby forming a first baseline along the first direction. Ink is ejected from a second nozzle portion of the inkjet head, which is disposed at a distance from the first nozzle portion in the first direction, thereby forming the first block and the second block. The first block is formed on one side of the first baseline in a second direction orthogonal to the first direction, and the second block is formed on the other side of the first baseline in the second direction. Multiple first baselines are formed at open intervals in the second direction. Multiple first blocks are arranged along the second direction, each located on one side of a plurality of first baselines. Multiple second blocks are arranged along the second direction, each located on the other side of one of the multiple first baselines. The plurality of said first blocks and the plurality of said second blocks are arranged in a staggered manner in the second direction without overlapping. The set of the first blocks forms the first graphic, and the set of the second blocks forms the second graphic. The inkjet head is configured to rotate about an inclined axis extending along a third direction orthogonal to the first and second directions. The first and second figures each contain markings indicating the rotation direction of the tilt axis.

7. A printing apparatus that prints a test pattern onto a medium by ejecting ink from an inkjet head having a plurality of nozzles, characterized in that... Ink is ejected from the first nozzle portion of the inkjet head into the medium, thereby forming a first baseline along a first direction. Ink is ejected from a second nozzle portion of the inkjet head, which is disposed at a distance from the first nozzle portion in the first direction, thereby forming the first block and the second block. The first block is formed on one side of the first baseline in a second direction orthogonal to the first direction, and the second block is formed on the other side of the first baseline in the second direction. Multiple first baselines are formed at open intervals in the second direction. Multiple first blocks are arranged along the second direction, each located on one side of a plurality of first baselines. Multiple second blocks are arranged along the second direction, each located on the other side of one of the multiple first baselines. The plurality of said first blocks and the plurality of said second blocks are arranged in a staggered manner in the second direction without overlapping. The set of the first blocks forms the first graphic, and the set of the second blocks forms the second graphic. The inkjet head is configured to rotate about an inclined axis extending along a third direction orthogonal to the first and second directions. The first and second figures each contain markings indicating the rotation direction of the tilt axis.

Images