Inkjet printer

Abstract

To determine an adjustment value for properly moving a medium.SOLUTION: A first printing section 71 of a printer 100 discharges ink from an upstream nozzle 24a of an ink head 22 and prints a plurality of first graphics F1 of an adjustment pattern PT1 on a medium 5. A second printing section 72 discharges ink from a downstream nozzle 24b while moving the medium 5 in a sub-scanning direction X and prints a plurality of second graphics F2 of the adjustment pattern PT1 on the medium 5. A detection section 73 detects positions of the first graphics F1 and the second graphics F2 printed on the medium 5 by a sensor 32. A calculation section 74 calculates deviation amount V1 in a main scanning direction Y between a first reference line L11 and a first comparison line L21 for each adjustment pair G1 having the first graphics F1 and the second graphics F2. An adjustment value determination section 75 determines an adjustment value A1 when moving the medium 5 in the sub-scanning direction X from a candidate adjustment value V2 corresponding to the deviation amount V1 for each adjustment pair G1 so that the deviation amount V1 becomes small.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to an inkjet printer. [Background technology]

[0002] For example, Patent Document 1 discloses a printer equipped with a platen that supports a medium and an ink head that ejects ink toward the medium supported by the platen. The ink head is mounted on a carriage that is slidably engaged with a guide rail that extends in the main scanning direction. The medium supported by the platen is configured to be movable in the sub-scanning direction.

[0003] In the above printer, printing of one line in the main scanning direction is performed by ejecting ink from the ink head while moving the carriage and ink head in the main scanning direction. After printing of one line is completed, the medium supported by the platen is moved a predetermined distance in the sub-scanning direction. After moving the medium a predetermined distance in the sub-scanning direction, printing of the next line is performed. By repeating this process of moving the medium in the sub-scanning direction and printing one line, the target print image can be printed on the medium. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-196537 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the printer may print on media of various thicknesses or materials. When the media is moved in the sub-scanning direction, differences in thickness or material may cause discrepancies in the amount of movement of the media.

[0006] The present invention has been made in view of the above points, and an object of the present invention is to provide an inkjet printer that can move a medium appropriately. [Means for solving the problem]

[0007] The inkjet printer according to the present invention includes a platen, an ink head, a sensor head, a first movement mechanism, a second movement mechanism, and a control device. The platen supports a medium. The ink head ejects ink. The sensor head has a sensor that detects an adjustment pattern printed on the medium. The first movement mechanism moves the ink head in a main scanning direction during printing and moves the sensor head in the main scanning direction when detecting the adjustment pattern. The second movement mechanism moves the medium supported by the platen from the upstream side to the downstream side in a sub-scanning direction. The ink head includes an upstream nozzle row having a plurality of upstream nozzles aligned in the sub-scanning direction, and a downstream nozzle row having a plurality of downstream nozzles aligned in the sub-scanning direction downstream of the upstream nozzle row in the sub-scanning direction. The adjustment pattern includes a first pattern and a second pattern. The first pattern includes a plurality of first figures aligned in the main scanning direction and including a first reference line extending diagonally between the main scanning direction and the sub-scanning direction. The second pattern includes a plurality of second figures arranged in the main scanning direction to form pairs with the first figures, each including a first comparison line extending diagonally between the main scanning direction and the sub-scanning direction. When the pair of first and second figures is arranged as an adjustment set, the first and second figures in the adjustment set at least partially overlap in the sub-scanning direction, and the first and second figures in the adjustment set are shifted by a predetermined adjustment interval in the sub-scanning direction as they move from one side of the main scanning direction to the other. For each adjustment set, candidate adjustment values ​​for moving the medium supported by the platen in the sub-scanning direction are preset. The control device includes a memory unit, a first printing unit, a second printing unit, a detection unit, a calculation unit, and an adjustment value determination unit. The memory unit stores print data for the adjustment pattern. The first printing unit ejects ink from the upstream nozzles while moving the ink head in the main scanning direction, thereby printing the first pattern of the adjustment pattern on a medium supported by the platen.The second printing unit ejects ink from the downstream nozzles while moving the ink head in the main scanning direction and moving the medium supported by the platen in the sub-scanning direction to print the second pattern of the adjustment pattern on the medium supported by the platen. The detection unit moves the sensor head in the main scanning direction and uses the sensor to detect the positions of the first figures and the second figures printed on the medium supported by the platen. The calculation unit calculates the amount of deviation of the first comparison line from the first reference line in the main scanning direction for each adjustment group. The adjustment value determination unit determines an adjustment value when moving the medium supported by the platen in the sub-scanning direction from the candidate adjustment values ​​corresponding to the amount of deviation for each adjustment group so as to reduce the amount of deviation.

[0008] In the inkjet printer, the first reference line of the first graphic printed with ink ejected from the upstream nozzles and the first comparison line of the second graphic printed with ink ejected from the downstream nozzles extend diagonally between the main scanning direction and the sub-scanning direction. Therefore, if a deviation occurs in the movement of the medium in the sub-scanning direction, the amount of deviation in the sub-scanning direction and the amount of deviation in the main scanning direction of the first comparison line relative to the first reference line are proportional to each other. Therefore, by calculating the amount of deviation of the first comparison line relative to the first reference line, the amount of deviation in the sub-scanning direction of the medium can be estimated. Therefore, an adjustment value for moving the medium supported by the platen in the sub-scanning direction can be appropriately determined based on the amount of deviation in the main scanning direction of the first comparison line relative to the first reference line for each adjustment group. Therefore, by adjusting the amount of movement of the medium in the sub-scanning direction using the adjustment value determined by the adjustment value determination unit, the medium can be appropriately moved in the sub-scanning direction. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a front view showing a printer according to an embodiment. [Figure 2] FIG. 2 is a cross-sectional view of the printer taken along line II-II in FIG. [Figure 3]FIG. 2 is a schematic diagram showing the configuration of the bottom surface of a print head. [Figure 4] FIG. 1 is a block diagram of a printer according to an embodiment. [Figure 5] FIG. 10 is a diagram schematically illustrating an example of an adjustment pattern. [Figure 6] FIG. 4 is a diagram schematically illustrating an example of a first pattern of the adjustment pattern. [Figure 7] FIG. 10 is a diagram schematically illustrating an example of a second pattern of the adjustment pattern. [Figure 8] FIG. 1 is a diagram schematically illustrating two adjacent adjustment sets. [Figure 9] 10 is a flowchart showing a procedure for determining an adjustment value. [Figure 10] FIG. 10 is a diagram showing a first approximate line and a second approximate line according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. It should be noted that the embodiments described here are not intended to limit the present invention in any particular way. Furthermore, the same reference numerals are used to designate components and parts that perform the same functions, and redundant descriptions will be omitted or simplified as appropriate.

[0011] FIG. 1 is a front view of an inkjet printer (hereinafter simply referred to as the printer) 100 according to this embodiment. FIG. 2 is a cross-sectional view of the printer 100 taken along the line II-II in FIG. 1. The symbols F, Rr, L, R, U, and D in the drawings indicate the front, rear, left, right, top, and bottom of the printer 100, respectively. Symbol Y indicates the main scanning direction. In this embodiment, the main scanning direction Y is, for example, the left-right direction. Symbol X indicates the sub-scanning direction. The sub-scanning direction X is a direction different from the main scanning direction Y. The sub-scanning direction X intersects (here, is perpendicular to) the main scanning direction Y in a plan view. The sub-scanning direction X is, for example, the front-to-rear direction. In this embodiment, the rear side of the sub-scanning direction X is referred to as the upstream side. The front side of the sub-scanning direction X is referred to as the downstream side. However, these directions are merely defined for convenience of explanation and do not limit the installation mode of the printer 100 or the present invention in any way.

[0012] Printer 100 is an inkjet printer. As shown in FIG. 1, printer 100 prints on medium 5. Medium 5 is, for example, rolled recording paper, commonly known as roll paper. However, the type of medium 5 is not particularly limited. Medium 5 may be plain paper, inkjet printing paper, a sheet or film made of resin such as polyvinyl chloride or polyester, a plate material, a fabric such as woven or nonwoven fabric, or other medium. Furthermore, the thickness of medium 5 is not particularly limited, and may be relatively thick or relatively thin.

[0013] As shown in FIG. 1, the printer 100 includes a printer body 11. The printer body 11 has a casing that extends in the main scanning direction Y. The printer body 11 is supported by legs 12. The legs 12 extend downward from the bottom surface of the printer body 11. In this embodiment, the printer body 11 is provided with an operation panel 13. The operation panel 13 has a display screen 14 that displays information regarding the status of the printer 100 and information regarding adjustment of the amount of movement of the medium 5 in the sub-scanning direction X, and operation keys 15. A user can display various information on the display screen 14 by, for example, operating the operation keys 15.

[0014] As shown in Figure 2, the printer 100 includes a platen 16. The platen 16 supports the medium 5. Here, the upper surface of the platen 16 extends in the main scanning direction Y and the sub-scanning direction X. The medium 5 is placed on the upper surface of the platen 16. Printing is performed on the medium 5 on the platen 16.

[0015] 1, the printer 100 includes a guide rail 18, a print head 20, and a sensor head 30. The guide rail 18 is disposed above the platen 16. The guide rail 18 extends in the main scanning direction Y.

[0016] The print head 20 is related to printing. The print head 20 is disposed above the platen 16. The print head 20 is configured to be movable in the main scanning direction Y. FIG. 3 is a schematic diagram showing the configuration of the bottom surface of the print head 20. As shown in FIG. 3, the print head 20 includes an ink carriage 21 and multiple ink heads 22.

[0017] As shown in FIG. 1, the ink carriage 21 is slidably engaged with the guide rail 18 and is configured to be movable in the main scanning direction Y along the guide rail 18. As shown in FIG. 2, the ink head 22 is disposed above the platen 16. The ink head 22 ejects ink toward the medium 5 supported by the platen 16. The ink head 22 is mounted on the ink carriage 21. Here, the ink head 22 is provided on the ink carriage 21 so that its bottom surface is exposed downward, and is supported by the ink carriage 21. The number of ink heads 22 is not particularly limited. In this embodiment, there are four ink heads 22, as shown in FIG. 3. The four ink heads 22 are arranged side by side in the main scanning direction Y.

[0018] In this embodiment, one ink head 22 has a plurality of nozzles 23 and a nozzle surface 28 in which the plurality of nozzles 23 are formed. The nozzle surface 28 forms the bottom surface of the ink head 22. In one ink head 22, the plurality of nozzles 23 are arranged side by side in the sub-scanning direction X. Here, in one ink head 22, the row of the plurality of nozzles 23 arranged side by side in the sub-scanning direction X is referred to as a nozzle row 25.

[0019] In this embodiment, of the multiple nozzles 23, the nozzles 23 arranged on the upstream side (here, the rear side) in the sub-scanning direction X are referred to as upstream nozzles 24a. A row of the multiple upstream nozzles 24a is referred to as upstream nozzle row 26a. The upstream nozzle row 26a has multiple upstream nozzles 24a arranged side by side in the sub-scanning direction X. Of the multiple nozzles 23, the nozzles 23 arranged on the downstream side (here, the front side) in the sub-scanning direction X are referred to as downstream nozzles 24b. A row of the multiple downstream nozzles 24b is referred to as downstream nozzle row 26b. The downstream nozzle row 26b is arranged downstream of the upstream nozzle row 26a in the sub-scanning direction X. The downstream nozzle row 26b has multiple downstream nozzles 24b arranged side by side in the sub-scanning direction X.

[0020] The number of upstream nozzles 24a is the same as the number of downstream nozzles 24b. In other words, the length of the upstream nozzle row 26a is the same as the length of the downstream nozzle row 26b. Here, when the nozzle row 25 is divided into two (here, equally divided) in the sub-scanning direction X, the upstream portion of the nozzle row 25 is referred to as the upstream nozzle row 26a. When the nozzle row 25 is divided into two in the sub-scanning direction X, the downstream portion of the nozzle row 25 is referred to as the downstream nozzle row 26b. However, the number of divisions of the nozzle row 25 is not limited to two, and may be three or more. As long as the downstream nozzle row 26b is arranged downstream of the upstream nozzle row 26a in the sub-scanning direction X, the position of the upstream nozzle row 26a relative to the nozzle row 25 and the position of the downstream nozzle row 26b relative to the nozzle row 25 are not particularly limited.

[0021] In this embodiment, different color inks are ejected from each nozzle row 25. In other words, different color inks are ejected from each ink head 22. For example, each ink head 22 ejects ink of one of process color inks such as cyan ink, magenta ink, yellow ink, and black ink, and spot color inks such as clear ink and white ink.

[0022] As shown in FIG. 1, the sensor head 30 is disposed above the platen 16. The sensor head 30 is disposed alongside the print head 20 in the main scanning direction Y. Here, the sensor head 30 is disposed to the left of the print head 20, but it may also be disposed to the right of the print head 20. The sensor head 30 is configured to be movable in the main scanning direction Y. The sensor head 30 has a sensor carriage 31 and a sensor 32.

[0023] The sensor carriage 31 is slidably engaged with the guide rail 18 and is configured to be movable in the main scanning direction Y along the guide rail 18 .

[0024] The sensor 32 is disposed above the platen 16. The sensor 32 is provided on the sensor carriage 31 and supported by the sensor carriage 31. The sensor 32 is a sensor for detecting an adjustment pattern PT1 (see FIG. 5 ), which will be described later, printed on the medium 5. The sensor 32 detects the position of the adjustment pattern PT1 and the position of the boundary between the adjustment pattern PT1 and the medium 5. The type of the sensor 32 is not particularly limited, but may be, for example, an optical type. The sensor 32 is, for example, a photosensor. The sensor 32 is capable of detecting color and may be a sensor capable of expressing color using RGB, for example.

[0025] In this embodiment, the print head 20 and the sensor head 30 are connectable. The sensor head 30 is capable of moving independently in the main scanning direction Y, separate from the print head 20. The print head 20 is connected to the sensor head 30, and is capable of moving together with the sensor head 30 in the main scanning direction Y. However, the print head 20 may also be capable of moving independently in the main scanning direction Y, separate from the sensor head 30.

[0026] In this embodiment, as shown in FIG. 1 , the printer 100 includes a first movement mechanism 41 and a second movement mechanism 42. The first movement mechanism 41 moves the ink head 22 in the main scanning direction Y during printing and moves the sensor head 30 in the main scanning direction Y when detecting the adjustment pattern PT1. The configuration of the first movement mechanism 41 is not particularly limited. In this embodiment, the first movement mechanism 41 includes left and right pulleys 51 a and 51 b provided around both left and right ends of the guide rail 18, a belt 52 wound around the left and right pulleys 51 a and 51 b, and a carriage motor 53 connected to the right pulley 51 b. The sensor head 30 is fixed to the belt 52. When the carriage motor 53 is driven, the right pulley 51 b rotates, causing the belt 52 to move. This causes the sensor head 30 to move in the main scanning direction Y. When the print head 20 is connected to the sensor head 30, the print head 20 (here, the ink carriage 21 and the multiple ink heads 22 (see FIG. 3)) moves in the main scanning direction Y together with the sensor head 30.

[0027] The second movement mechanism 42 is a mechanism that moves the medium 5 supported by the platen 16 in the sub-scanning direction X. Here, the second movement mechanism 42 moves the medium 5 supported by the platen 16 from the upstream side to the downstream side in the sub-scanning direction X (from the rear side to the front side in this embodiment). The configuration of the second movement mechanism 42 is not particularly limited. In this embodiment, the second movement mechanism 42 includes, for example, a grit roller 55 provided on the platen 16, a pinch roller 56 that sandwiches the medium 5 together with the grit roller 55, and a feed motor 57 connected to the grit roller 55. The feed motor 57 is driven to rotate the grit roller 55. As a result, the medium 5 sandwiched between the grit roller 55 and the pinch roller 56 moves from the upstream side to the downstream side in the sub-scanning direction X.

[0028] The printer 100 includes a control device 60. The control device 60 is configured, for example, by a microcomputer. The control device 60 includes an interface (I / F) that receives print data and the like from an external device such as a host computer, a central processing unit (CPU) that executes instructions of a control program, a read-only memory (ROM) that stores the program executed by the CPU, a random access memory (RAM) used as a working area for expanding the program, and memory that stores the program and various data. Note that the control device 60 does not necessarily have to be provided inside the printer main body 11 of the printer 100. For example, the control device 60 may be a computer or the like that is installed outside the printer main body 11 of the printer 100 and is connected to the printer 100 via wired or wireless communication so as to be able to communicate with the printer 100.

[0029] Figure 4 is a block diagram of the printer 100. In this embodiment, as shown in Figure 4, the control device 60 is communicatively connected to the operation panel 13, the ink head 22, the sensor 32, the first movement mechanism 41 (more specifically, the carriage motor 53), and the second movement mechanism 42 (more specifically, the feed motor 57). The control device 60 is configured to be able to control the operation panel 13, the ink head 22, the sensor 32, the first movement mechanism 41, and the second movement mechanism 42.

[0030] Incidentally, when printing with the printer 100, printing may be performed on media 5 of various thicknesses or media 5 made of different materials. When moving the medium 5 in the sub-scanning direction X, if the thickness or material of the medium 5 varies, deviations may occur in the amount of movement of the medium 5 in the sub-scanning direction X. Deviations in the amount of movement of the medium 5 may result in a decrease in print quality, so it is preferable that deviations in the amount of movement of the medium 5 are unlikely to occur even when the thickness or material of the medium 5 varies.

[0031] For example, in the past, a test pattern for adjusting the deviation in the amount of movement of the medium 5 in the sub-scanning direction X was printed on the medium 5, and the user visually checked the test pattern to determine an adjustment value for adjusting the deviation in the amount of movement of the medium 5 in the sub-scanning direction X. In this case, because the adjustment value was determined based on the user's experience, it was sometimes not possible to appropriately adjust the deviation in the amount of movement of the medium 5 in the sub-scanning direction X.

[0032] Therefore, in this embodiment, an adjustment value A1 (see FIG. 9) for adjusting the movement of the medium 5 in the sub-scanning direction X is automatically determined. In the printer 100 according to this embodiment, as shown in FIG. 4, the control device 60 includes a storage unit 70, a first printing unit 71, a second printing unit 72, a detection unit 73, a calculation unit 74, and an adjustment value determination unit 75. Each of the units 71 to 75 constituting the control device 60 may be realized by one or more processors, may be incorporated into a circuit, or may be programmed by predetermined software.

[0033] Fig. 5 is a diagram schematically showing an example of an adjustment pattern PT1. In this embodiment, to determine the adjustment value A1, first, an adjustment pattern PT1 as shown in Fig. 5 is printed on the medium 5 supported by the platen 16. As shown in Fig. 5, the adjustment pattern PT1 includes a first pattern PT11 and a second pattern PT12.

[0034] FIG. 6 is a schematic diagram illustrating an example of a first pattern PT11 of the adjustment pattern PT1. As shown in FIG. 6, the first pattern PT11 has multiple first figures F1. While the number of first figures F1 included in the first pattern PT11 is not particularly limited, seven figures are included here. In the following description, the first figures F1 will be appropriately assigned reference characters F1a to F1g from left to right. Reference character F1 will be used when describing all of the first figures F1a to F1g. The first figures F1a to F1g are arranged side by side in the main scanning direction Y. The first figures F1a to F1g are arranged at equal intervals in the main scanning direction Y, but they do not have to be spaced apart at equal intervals. In this embodiment, the first figures F1a to F1g have the same shape and size. Here, the shape of the first figures F1 is a parallelogram.

[0035] The first figure F1 has a first reference line L11, a second reference line L12, a first reference connecting line L13, and a second reference connecting line L14. The first reference line L11 extends obliquely between the main scanning direction Y and the sub-scanning direction X. The second reference line L12 is arranged alongside the first reference line L11 in the main scanning direction Y. Here, the second reference line L12 is arranged to the right of the first reference line L11. One end of the first reference line L11 and one end of the second reference line L12 are at the same position in the sub-scanning direction X. The other end of the first reference line L11 and the other end of the second reference line L12 are at the same position in the sub-scanning direction X. The length of the first reference line L11 and the length of the second reference line L12 are the same. The second reference line L12 is parallel to the first reference line L11. Therefore, the second reference line L12 extends obliquely between the main scanning direction Y and the sub-scanning direction X.

[0036] In this embodiment, the angle R11 formed between the axis L31 extending in the main scanning direction Y and the first reference line L11, and the angle R12 formed between the axis L31 and the second reference line L12 are 10 to 80 degrees, preferably 30 to 75 degrees, particularly preferably 45 to 70 degrees, for example 60 degrees.

[0037] The first reference connecting line L13 is a line connecting one end (here, the rear end) of the first reference line L11 and one end of the second reference line L12. The second reference connecting line L14 is a line connecting the other end (here, the front end) of the first reference line L11 and the other end of the second reference line L12. Here, the first reference connecting line L13 and the second reference connecting line L14 extend in the main scanning direction Y. The first reference connecting line L13 and the second reference connecting line L14 are arranged so as to be parallel to each other. The length of the first reference connecting line L13 and the length of the second reference connecting line L14 are the same.

[0038] FIG. 7 is a schematic diagram illustrating an example of a second pattern PT12 of the adjustment pattern PT1. As shown in FIG. 7, the second pattern PT12 has multiple second figures F2. The number of second figures F2 is the same as the number of first figures F1, which is seven in this example. In the following description, the second figures F2 will be appropriately assigned reference characters F2a to F2g from left to right. Reference character F2 will be used when describing all of the second figures F2a to F2g. The second figures F2a to F2g are arranged side by side in the main scanning direction Y. The second figures F2a to F2g are arranged at equal intervals in the main scanning direction Y, but they do not have to be spaced at equal intervals. In this embodiment, the second figures F2a to F2g have the same shape and size. The second figure F2 has the same shape and size as the first figure F1. Here, the shape of the second figure F2 is a parallelogram.

[0039] The second figure F2 has a first comparison line L21, a second comparison line L22, a first comparison connecting line L23, and a second comparison connecting line L24. The first comparison line L21 extends obliquely between the main scanning direction Y and the sub-scanning direction X. In this embodiment, the first comparison line L21 is parallel to the first reference line L11 of the first figure F1 and is parallel to the second reference line L12. The second comparison line L22 is arranged alongside the second comparison line L21 in the main scanning direction Y. Here, the second comparison line L22 is arranged to the right of the first comparison line L21. One end of the first comparison line L21 and one end of the second comparison line L22 are at the same position in the sub-scanning direction X. The other end of the first comparison line L21 and the other end of the second comparison line L22 are at the same position in the sub-scanning direction X. The length of the first comparison line L21 and the length of the second comparison line L22 are the same. The second comparison line L22 is parallel to the first comparison line L21. Here, the second comparison line L22 is parallel to the first reference line L11 of the first figure F1 and also parallel to the second reference line L12. Therefore, the second comparison line L22 extends obliquely between the main scanning direction Y and the sub-scanning direction X.

[0040] In this embodiment, the angle R21 formed between the axis L31 extending in the main scanning direction Y and the first comparison line L21, and the angle R22 formed between the axis L31 and the second comparison line L22 are 10 to 80 degrees, preferably 30 to 75 degrees, particularly preferably 45 to 70 degrees, for example 60 degrees. Here, the angles R21 and R22 are the same as the angle R11 formed between the axis L31 and the first reference line L11 (see FIG. 6), and are also the same as the angle R12 formed between the axis L31 and the second reference line L12 (see FIG. 6).

[0041] As shown in FIG. 7, the first comparison connecting line L23 is a line connecting one end (here, the rear end) of the first comparison line L21 and one end of the second comparison line L22. The second comparison connecting line L24 is a line connecting the other end (here, the front end) of the first comparison line L21 and the other end of the second comparison line L22. Here, the first comparison connecting line L23 and the second comparison connecting line L24 extend in the main scanning direction Y. The first comparison connecting line L23 and the second comparison connecting line L24 are arranged so as to be parallel to each other. In this embodiment, the first comparison connecting line L23 and the second comparison connecting line L24 are parallel to the first reference connecting line L13 (see FIG. 6) of the first figure F1 and also parallel to the second reference connecting line L14 (see FIG. 6). The length of the first comparison connecting line L23 and the length of the second comparison connecting line L24 are the same.

[0042] As shown in FIG. 5, each of the multiple second figures F2 is paired with a first figure F1. Here, the pair of first figure F1 and second figure F2 is referred to as an adjustment set G1. In this embodiment, there are seven adjustment sets G1. In each adjustment set G1, the first figure F1 and the second figure F2 are positioned at the same position in the main scanning direction Y and at least partially overlap in the sub-scanning direction X. In the following description, the adjustment sets G1 will be appropriately assigned the reference characters G1a to G1g from left to right. The reference character G1 will be used when describing all of the adjustment sets G1a to G1g. FIG. 8 is a schematic diagram showing two adjacent adjustment sets G1. As shown in FIG. 8, for example, the adjustment set G1a has a first figure F1a and a second figure F2a. The adjustment set G1b has a first figure F1b and a second figure F2b.

[0043] In this embodiment, the first and second figures F1 and F2 in the adjustment set G1 are arranged so as to be shifted in the sub-scanning direction X by a predetermined adjustment distance SP1 (see FIG. 8) from one side to the other in the main scanning direction Y, for example, from left to right. Here, the first figures F1a to F1g are positioned at the same position in the sub-scanning direction X. From one side (left in this case) to the other side (right in this case) in the main scanning direction Y, the second figure F2 is arranged so as to be shifted downstream in the sub-scanning direction X by the adjustment distance SP1. The second figures F2 adjacent to each other in the main scanning direction Y are arranged so as to be shifted in the sub-scanning direction X by the adjustment distance SP1.

[0044] 5, in this embodiment, a candidate adjustment value V2 is set in advance for each adjustment group G1 when the medium 5 supported by the platen 16 is moved in the sub-scanning direction X. The candidate adjustment value V2 is a value that can become the actual adjustment value A1 (see FIG. 9) when the medium 5 supported by the platen 16 is moved in the sub-scanning direction X.

[0045] 9 is a flowchart showing the procedure for determining the adjustment value A1. Next, the procedure for the printer 100 to automatically determine the adjustment value A1 will be described with reference to the flowchart in FIG.

[0046] 4, in this embodiment, print data DT1 of adjustment pattern PT1 is stored in the storage unit 70. The print data DT1 is, for example, raster data.

[0047] 9, first, in step S101, the first printing unit 71 of FIG. 4 prints a first pattern PT11 (see FIG. 6) of the adjustment pattern PT1 based on the print data DT1 of the adjustment pattern PT1 stored in the storage unit 70. Here, the first printing unit 71 ejects ink from the upstream nozzles 24a (see FIG. 3) while moving the ink head 22 in the main scanning direction Y, to print a plurality of first figures F1 of the first pattern PT11 onto the medium 5 supported by the platen 16.

[0048] Specifically, the first printing unit 71 controls the first movement mechanism 41 to move the print head 20 in the main scanning direction Y, thereby moving the ink head 22 in the main scanning direction Y. While the ink head 22 is moving in the main scanning direction Y, ink is ejected from the upstream nozzles 24a to print multiple first figures F1 on the medium 5. In this embodiment, while the ink head 22 is moving in the main scanning direction Y, multiple first figures F1 are printed collectively. For example, while the ink head 22 is moving back and forth in the main scanning direction Y (e.g., during one reciprocating movement), multiple first figures F1 are printed on the medium 5. Here, while the first pattern PT11 is being printed, the first printing unit 71 does not drive the feed motor 57 (see FIG. 4) of the second movement mechanism 42, and the medium 5 supported by the platen 16 does not move in the sub-scanning direction X.

[0049] In this embodiment, the first printing unit 71 prints a plurality of first figures F1 of the first pattern PT11 using ink of a predetermined color. Here, the predetermined color ink is not particularly limited, but is, for example, black ink. Here, the plurality of first figures F1 are printed on the medium 5 supported by the platen 16 by ejecting black ink from the upstream nozzles 24a of the ink head 22 that ejects black ink.

[0050] 9, the second printing unit 72 of FIG. 4 prints a second pattern PT12 (see FIG. 7) of the adjustment pattern PT1 based on the print data DT1 of the adjustment pattern PT1 stored in the memory unit 70. Here, the second printing unit 72 ejects ink from the downstream nozzles 24b (see FIG. 3) while moving the ink head 22 in the main scanning direction Y and moving the medium 5 supported by the platen 16 in the sub-scanning direction X, thereby printing the second pattern PT12 on the medium 5 supported by the platen 16.

[0051] Specifically, first, the second printing unit 72 controls the second movement mechanism 42 to move the medium 5 supported by the platen 16 downstream in the sub-scanning direction X to a position where the movement trajectory of the downstream nozzle 24b of the ink head 22 in the main scanning direction Y overlaps with at least one of the first figures F1. Thereafter, the second printing unit 72 starts printing from the second figure F2g, which is located furthest downstream among the multiple second figures F2, and then prints the second figures F2f, F2e, F2d, F2c, F2b, and F2a in that order.

[0052] Here, the second printing unit 72 controls the first movement mechanism 41 to move the ink head 22 in the main scanning direction Y, and while the ink head 22 is moving in the main scanning direction Y, ejects ink from the downstream nozzles 24b to print the second figure F2g on the medium 5. Then, the second printing unit 72 controls the second movement mechanism 42 to move the medium 5 supported by the platen 16 downstream in the sub-scanning direction X by an adjustment interval SP1 (see FIG. 8). Next, the second printing unit 72 ejects ink from the downstream nozzles 24b while moving the ink head 22 in the main scanning direction Y, thereby printing the second figure F2f on the medium 5. Subsequently, by repeatedly moving the medium 5 downstream in the sub-scanning direction X by the adjustment interval SP1 and moving the ink head 22 in the main scanning direction Y while ejecting ink from the downstream nozzles 24b, all of the second figure F2 can be printed.

[0053] In this embodiment, the second printing unit 72 prints multiple second figures F2 of the second pattern PT12 using ink of a predetermined color. Here, the color of ink used to print the first figure F1 and the color of ink used to print the second figure F2 are the same, but may be different. The predetermined color of ink used to print the second figure F2 is not particularly limited, but is, for example, black ink. Here, the multiple second figures F2 are printed on the medium 5 supported by the platen 16 by ejecting black ink from the downstream nozzles 24b of the ink head 22 that ejects black ink.

[0054] After printing the adjustment pattern PT1 on the medium 5 in this manner, next, in step S105 of FIG. 9, the detection unit 73 of FIG. 4 detects the position of the adjustment pattern PT1 printed on the medium 5. Here, the detection unit 73 uses the sensor 32 of the sensor head 30 to detect the positions of the multiple first figures F1 and multiple second figures F2 of the adjustment pattern PT1 printed on the medium 5. Specifically, the detection unit 73 moves the medium 5 supported by the platen 16 in the sub-scanning direction X to a position where the sensor 32 can detect the adjustment pattern PT1 printed on the medium 5. Here, for example, in the adjustment set G1, the medium 5 is moved in the sub-scanning direction X to a position where the sensor 32 can pass over a position where the first figure F1 and the second figure F2 overlap in the sub-scanning direction X, for example, over the center in the sub-scanning direction X of the figure formed by combining the first figure F1 and the second figure F2.

[0055] The detection unit 73 then moves the first moving mechanism 41 to move the sensor head 30 in the main scanning direction Y. While the sensor head 30 is moving in the main scanning direction Y, the detection unit 73 detects the positions of the first figure F1 and the second figure F2 in the main scanning direction Y using the sensor 32. Here, the detection unit 73 detects the positions in the main scanning direction Y of the first reference line L11 of the first figure F1 and the first comparison line L21 of the second figure F2. However, the detection unit 73 may also estimate and detect the positions in the main scanning direction Y of the first reference line L11 and the first comparison line L21 by detecting the positions in the main scanning direction Y of the leftmost and rightmost lines in the main scanning direction Y among the first reference line L11, the second reference line L12, the first comparison line L21, and the second comparison line L22 for each adjustment group G1. In this manner, information relating to the detected positions of the first figure F1 and the second figure F2 is stored in the storage unit .

[0056] Next, in step S107 of FIG. 9, the calculation unit 74 of FIG. 4 calculates, for each adjustment group G1, a deviation V1 (see FIG. 8) of the second figure F2 relative to the first figure F1 in the main scanning direction Y. Here, the deviation V1 for each adjustment group G1 is also the deviation in the main scanning direction Y of the first comparison line L21 of the second figure F2 relative to the first reference line L11 of the first figure F1. Here, as shown in FIG. 8, the calculation unit 74 determines, for each adjustment group G1, the length in the main scanning direction Y of the first figure F1 and the second figure F2 when treated as a single figure. In this embodiment, the deviation V1 is calculated as the distance in the main scanning direction Y between the leftmost line and the rightmost line among the first reference line L11, the second reference line L12, the first comparison line L21, and the second comparison line L22 in the adjustment group G1. 8, for the adjustment group G1a, the distance between the first reference line L11 and the second comparison line L22 in the main scanning direction Y is the deviation amount V1. Here, the deviation amount V1 of each adjustment group G1 calculated by the calculation unit 74 is stored in the memory unit 70.

[0057] Next, in step S109 of FIG. 9, the adjustment value determination unit 75 of FIG. 4 determines the adjustment value A1 for moving the medium 5 supported by the platen 16 in the sub-scanning direction X based on the deviation amount V1 of each adjustment set G1 calculated by the calculation unit 74. Here, the adjustment value determination unit 75 determines the candidate adjustment value V2 set for the adjustment set G1 with the smallest deviation amount V1 as the adjustment value A1. In the example of FIG. 5, the adjustment set G1e has the smallest deviation amount V1. Therefore, the adjustment value determination unit 75 determines the candidate adjustment value V2 of the adjustment set G1e as the adjustment value A1.

[0058] In this embodiment, when printing on a medium 5 supported by a platen 16, printing is performed by moving the medium 5 in the sub-scanning direction X while adjusting the amount of movement of the medium 5 in the sub-scanning direction X using the adjustment value A1 determined by the adjustment value determination unit 75.

[0059] As described above, in this embodiment, as shown in FIG. 1, the printer 100 includes a platen 16 that supports the medium 5, an ink head 22 (see FIG. 3) that ejects ink, a sensor head 30, a first movement mechanism 41, a second movement mechanism 42, and a control device 60. The sensor head 30 has a sensor 32 that detects an adjustment pattern PT1 (see FIG. 5) printed on the medium 5. The first movement mechanism 41 moves the ink head 22 in the main scanning direction Y during printing, and moves the sensor head 30 in the main scanning direction Y when detecting the adjustment pattern PT1. The second movement mechanism 42 moves the medium 5 supported by the platen 16 from the upstream side to the downstream side in the sub-scanning direction X. As shown in FIG. 3, the ink head 22 includes an upstream nozzle row 26a and a downstream nozzle row 26b. The upstream nozzle row 26a has a plurality of upstream nozzles 24a arranged side by side in the sub-scanning direction X. The downstream nozzle row 26b has a plurality of downstream nozzles 24b arranged side by side in the sub-scanning direction X downstream of the upstream nozzle row 26a in the sub-scanning direction X. As shown in Fig. 5, the adjustment pattern PT1 has a first pattern PT11 and a second pattern PT12. As shown in Fig. 6, the first pattern PT11 has a plurality of first figures F1 arranged side by side in the main scanning direction Y and including a first reference line L11 extending obliquely between the main scanning direction Y and the sub-scanning direction X. As shown in Fig. 7, the second pattern PT12 has a plurality of second figures F2 arranged side by side in the main scanning direction Y to form pairs with the first figures F1 and including a first comparison line L21 extending obliquely between the main scanning direction Y and the sub-scanning direction X. 5, when a pair of first and second figures F1 and F2 are defined as an adjustment set G1, in the adjustment set G1, the first and second figures F1 and F2 at least partially overlap in the sub-scanning direction X, and as they move from one side of the main scanning direction Y to the other, the first and second figures F1 and F2 in the adjustment set G1 are shifted in the sub-scanning direction X by a predetermined adjustment interval SP1 (see FIG. 8). For each adjustment set G1, a candidate adjustment value V2 for moving the medium 5 supported by the platen 16 in the sub-scanning direction X is set in advance.

[0060] As shown in FIG. 4, the control device 60 includes a memory unit 70, a first printing unit 71, a second printing unit 72, a detection unit 73, a calculation unit 74, and an adjustment value determination unit 75. The memory unit 70 stores print data DT1 for the adjustment pattern PT1. As shown in step S101 of FIG. 9, the first printing unit 71 ejects ink from the upstream nozzles 24a while moving the ink head 22 in the main scanning direction Y, thereby printing a first pattern PT11 of the adjustment pattern PT1 on the medium 5 supported by the platen 16. As shown in step S103 of FIG. 9, the second printing unit 72 ejects ink from the downstream nozzles 24b while moving the ink head 22 in the main scanning direction Y and the medium 5 supported by the platen 16 in the sub-scanning direction X, thereby printing a second pattern PT12 of the adjustment pattern PT1 on the medium 5 supported by the platen 16. As shown in step S105 of FIG. 9, the detection unit 73 moves the sensor head 30 in the main scanning direction Y and detects the positions of the multiple first figures F1 and the multiple second figures F2 printed on the medium 5 using the sensor 32. As shown in step S107 of FIG. 9, the calculation unit 74 calculates the amount of deviation V1 (see FIG. 8) of the first comparison line L21 relative to the first reference line L11 in the main scanning direction Y for each adjustment set G1. As shown in step S109 of FIG. 9, the adjustment value determination unit 75 determines an adjustment value A1 for moving the medium 5 supported by the platen 16 in the sub-scanning direction X from the candidate adjustment value V2 corresponding to the amount of deviation V1 for each adjustment set G1 so as to reduce the amount of deviation V1.

[0061] In this embodiment, as shown in FIG. 5 , the first reference line L11 of the first graphic F1 printed with ink ejected from the upstream nozzle 24a and the first comparison line L21 of the second graphic F2 printed with ink ejected from the downstream nozzle 24b extend diagonally between the main scanning direction Y and the sub-scanning direction X. Therefore, if a deviation occurs in the movement of the medium 5 in the sub-scanning direction X, the amount of deviation in the movement in the sub-scanning direction X and the amount of deviation V1 in the main scanning direction Y of the first comparison line L21 relative to the first reference line L11 are proportional to each other. Therefore, by calculating the amount of deviation V1 of the first comparison line L21 relative to the first reference line L11, the amount of deviation in the movement of the medium 5 in the sub-scanning direction X can be estimated. Therefore, the adjustment value A1 for moving the medium 5 supported by the platen 16 in the sub-scanning direction X can be appropriately determined based on the amount of deviation V1 in the main scanning direction Y of the first comparison line L21 relative to the first reference line L11 for each adjustment group G1. Therefore, by adjusting the amount of movement of the medium 5 in the sub-scanning direction X using the adjustment value A1 determined by the adjustment value determination unit 75, the medium 5 can be moved in the sub-scanning direction X appropriately.

[0062] In this embodiment, the adjustment value determination unit 75 determines the candidate adjustment value V2 set in the adjustment set G1 (adjustment set G1e in FIG. 5) with the smallest deviation amount V1 as the adjustment value A1. If the deviation amount V1 is small, it is estimated that the deviation amount of movement in the sub-scanning direction X on the medium 5 is small. Therefore, by determining the candidate adjustment value V2 set in the adjustment set G1 with the small deviation amount V1 as the adjustment value A1, it is possible to appropriately suppress the deviation of movement in the sub-scanning direction X on the medium 5.

[0063] In this embodiment, the first reference line L11 and the first comparison line L21 are parallel to each other, as shown in Fig. 8. This allows the amount of deviation V1 in the main scanning direction Y of the first comparison line L21 relative to the first reference line L11 (in other words, the second figure F2 relative to the first figure F1) to be the same regardless of the position in the sub-scanning direction X.

[0064] In this embodiment, as shown in FIG. 8, the first figure F1 and the second figure F2 are parallelograms. The first figure F1 includes a first reference line L11, a second reference line L12 that is parallel to the first reference line L11 and aligned with the first reference line L11 in the fast scanning direction Y, a first reference connecting line L13, and a second reference connecting line L14. The first reference connecting line L13 connects one end of the first reference line L11 to one end of the second reference line L12. The second reference connecting line L14 connects the other end of the first reference line L11 to the other end of the second reference line L12. The second figure F2 includes a first comparison line L21, a second comparison line L22 that is parallel to the first comparison line L21 and aligned with the first comparison line L21 in the fast scanning direction Y, a first comparison connecting line L23, and a second comparison connecting line L24. The first comparison connecting line L23 connects one end of the first comparison line L21 to one end of the second comparison line L22. The second comparison connecting line L24 connects the other end of the first comparison line L21 to the other end of the second comparison line L22. By forming the first figure F1 and the second figure F2 into a parallelogram in this way, the first reference line L11 and the second reference line L12, which are opposite sides of the parallelogram, are arranged parallel to the first comparison line L21 and the second comparison line L22. Therefore, the amount of deviation V1 of the second figure F2 in the main scanning direction Y relative to the first figure F1 can be made the same regardless of the position in the sub-scanning direction X.

[0065] In this embodiment, the first figure F1 and the second figure F2 have the same shape. Furthermore, the first figure F1 and the second figure F2 have the same size. This allows data of the same shape and size to be repeatedly used when printing the adjustment pattern PT1, thereby reducing the amount of print data DT1 for the adjustment pattern PT1. Furthermore, because figures of the same shape and size are aligned in the main scanning direction Y, it is easy to control the printing of the adjustment pattern PT1.

[0066] In this embodiment, as shown in Fig. 8, the calculation unit 74 in Fig. 4 determines the length in the main scanning direction Y of the first figure F1 and the second figure F2 combined into one figure as the deviation amount V1 for each adjustment group G1. The length in the main scanning direction Y of the first figure F1 and the second figure F2 combined into one figure can be easily calculated by detecting the positions of the left and right ends of the one figure. Therefore, by determining the length in the main scanning direction Y of the first figure F1 and the second figure F2 combined into one figure as the deviation amount V1, it becomes easy to calculate the deviation amount V1.

[0067] In this embodiment, the first printing unit 71 prints the first pattern PT11 with ink of a predetermined color. The second printing unit 72 prints the second pattern PT12 with ink of the same predetermined color as the first pattern PT11. As a result, the first figure F1 and the second figure F2 are printed in one color. Therefore, when detecting the positions of the first figure F1 and the second figure F2 on the medium 5, it is sufficient to detect the boundary between the predetermined color and the medium 5. Therefore, it is easy to detect the positions of the first figure F1 and the second figure F2 on the medium 5.

[0068] In the above embodiment, the adjustment value determination unit 75 determined the candidate adjustment value set in the adjustment set G1 with the smallest deviation amount V1 as the adjustment value A1. However, the adjustment value determination unit 75 may also calculate an approximation formula F10 (see FIG. 10) based on the deviation amount V1 and candidate adjustment value V2 for each adjustment set G1, and determine the candidate adjustment value V2 corresponding to the smallest value of the deviation amount V1 in the approximation formula F10 as the adjustment value A1.

[0069] FIG. 10 is a diagram showing a first approximate line SL1 and a second approximate line SL2 according to another embodiment. In FIG. 10, the candidate adjustment values ​​V2 for the adjustment sets G1a to G1g are designated as candidate adjustment values ​​V2a to V2g, respectively. Here, as shown in FIG. 10, the approximate formula F10 includes a first approximate formula F11 and a second approximate formula F12. The first approximate formula F11 is a formula for the first approximate line SL1 in which the deviation amount V1 decreases as the candidate adjustment value V2 increases. In the example shown in FIG. 10, the first approximate line SL1 is a formula for the adjustment sets G1a, G1b, G1c, and G1d. The second approximate formula F12 is a formula for the second approximate line SL2 in which the deviation amount V1 increases as the candidate adjustment value V2 increases. In the example shown in FIG. 10, the second approximate line SL2 is a formula for the adjustment sets G1e, G1f, and G1g.

[0070] In this embodiment, the deviation amount V1 is smallest at the intersection P1 between the first approximate line SL1 and the second approximate line SL2. Therefore, the adjustment value determination unit 75 determines the candidate adjustment value V2 at the intersection P1 between the first approximate line SL1 and the second approximate line SL2 as the adjustment value A1 when moving the medium 5 in the sub-scanning direction X.

[0071] In this way, the approximate formula F10, which includes the first approximate formula F11 and the second approximate formula F12, is calculated, and the candidate adjustment value V2 corresponding to the minimum value of the deviation amount V1 in the approximate formula F10 is determined as the adjustment value A1. In this way, even if the number of adjustment sets G1 is small, if the approximate formula F10 can be calculated, the adjustment value A1 can be determined. Therefore, it is possible to reduce the number of adjustment sets G1, and as a result, the amount of ink required to print the adjustment pattern PT1 can be reduced.

[0072] In the above embodiment, the calculation unit 74 determined the length in the main scanning direction Y of the combined figure of the first figure F1 and the second figure F2 for each adjustment set G1 as the deviation amount V1. However, the deviation amount V1 may be the distance in the main scanning direction Y between the first reference line L11 of the first figure F1 and the first comparison line L21 of the second figure F2, or the distance in the main scanning direction Y between the second reference line L12 of the first figure F1 and the first comparison line L22 of the second figure F2. [Explanation of symbols]

[0073] 5 Medium 16 Platen 22 Ink head 24a Upstream nozzle 24b downstream nozzle 26a Upstream nozzle row 26b Downstream nozzle row 30 Sensor head 32 sensors 41 1st movement mechanism 42 Second movement mechanism 60 Control device 70 Memory section 71 1st Printing Department 72 2nd Printing Department 73 Detector 74 Calculation Unit 75 Adjustment value determination unit 100 Printers (inkjet printers) F1 First Figure F2 Second figure G1 adjustment group L11 1st reference line L21 1st comparison line PT1 Adjustment Pattern PT11 1st Pattern PT12 2nd pattern

Claims

1. a platen for supporting the media; an ink head that ejects ink; a sensor head having a sensor for detecting an adjustment pattern printed on a medium; a first movement mechanism that moves the ink head in a main scanning direction during printing and moves the sensor head in the main scanning direction when detecting the adjustment pattern; a second movement mechanism that moves the medium supported by the platen from the upstream side to the downstream side in the sub-scanning direction; a control device; Equipped with The ink head is an upstream nozzle row having a plurality of upstream nozzles arranged side by side in the sub-scanning direction; a downstream nozzle row having a plurality of downstream nozzles arranged side by side in the sub-scanning direction, downstream of the upstream nozzle row in the sub-scanning direction; Equipped with The adjustment pattern is a first pattern including a plurality of first figures arranged side by side in the main scanning direction and including a first reference line extending obliquely between the main scanning direction and the sub-scanning direction; a second pattern including a plurality of second figures, each of which includes a first comparison line that is arranged in the main scanning direction to be paired with the first figure and extends obliquely between the main scanning direction and the sub-scanning direction; Equipped with a pair of the first and second figures is set as an adjustment set, and in the adjustment set, at least a portion of the first and second figures overlap in the sub-scanning direction, and the first and second figures in the adjustment set are arranged to be shifted by a predetermined adjustment interval in the sub-scanning direction from one side to the other side in the main scanning direction, A candidate adjustment value for moving the medium supported by the platen in the sub-scanning direction is set in advance for each adjustment set, The control device a storage unit in which print data of the adjustment pattern is stored; a first printing unit that ejects ink from the upstream nozzles while moving the ink head in the main scanning direction to print the first pattern of the adjustment pattern on a medium supported by the platen; a second printing unit that ejects ink from the downstream nozzles while moving the ink head in the main scanning direction and moving a medium supported by the platen in the sub-scanning direction, thereby printing the second pattern of the adjustment pattern on the medium supported by the platen; a detection unit that moves the sensor head in the main scanning direction and detects the positions of the first and second figures printed on the medium supported by the platen using the sensor; a calculation unit that calculates a deviation amount of the first comparison line relative to the first reference line in the main scanning direction for each adjustment set; an adjustment value determination unit that determines an adjustment value when moving the medium supported by the platen in the sub-scanning direction from the candidate adjustment values ​​corresponding to the amount of deviation for each adjustment group so that the amount of deviation becomes small; An inkjet printer equipped with

2. 2. The inkjet printer according to claim 1, wherein the adjustment value determination unit determines the candidate adjustment value set in the adjustment set with the smallest amount of deviation as the adjustment value.

3. 2. The inkjet printer according to claim 1, wherein the adjustment value determination unit calculates an approximation formula based on the deviation amount and the candidate adjustment value for each adjustment group, and determines the candidate adjustment value corresponding to the minimum deviation amount in the approximation formula as the adjustment value.

4. The approximation formula is a first approximate equation for a first approximate line in which the deviation amount decreases as the candidate adjustment value increases; a second approximate equation for a second approximate straight line in which the deviation amount increases as the candidate adjustment value increases; and The inkjet printer according to claim 3 , wherein the adjustment value determination unit determines the candidate adjustment value at the intersection of the first approximation line and the second approximation line as the adjustment value.

5. 5. The inkjet printer according to claim 1, wherein the first reference line and the first comparison line are parallel to each other.

6. The first figure is The first reference line; a second reference line arranged next to the first reference line in the main scanning direction and parallel to the first reference line; and The second figure is the first comparison line; a second comparison line arranged next to the first comparison line in the main scanning direction and parallel to the first comparison line; 6. An ink jet printer according to claim 1, comprising:

7. The first figure is a first reference connecting line connecting one end of the first reference line and one end of the second reference line; a second reference connecting line connecting the other end of the first reference line and the other end of the second reference line; and The second figure is a first comparison connecting line connecting one end of the first comparison line and one end of the second comparison line; a second comparison connecting line connecting the other end of the first comparison line and the other end of the second comparison line; 7. The inkjet printer of claim 6, comprising:

8. 8. The inkjet printer according to claim 7, wherein the first and second figures have the same shape.

9. 9. The inkjet printer according to claim 7, wherein the first and second figures are parallelograms.

10. 10. The inkjet printer according to claim 6, wherein the calculation unit determines, for each adjustment pair, the length in the main scanning direction when the first graphic and the second graphic are treated as one graphic as the deviation amount.

11. 11. The inkjet printer according to claim 1, wherein the first and second figures are the same size.

12. the first printing unit prints the first pattern with ink of a predetermined color; 12. The inkjet printer according to claim 1, wherein the second printing unit prints the second pattern with ink of the predetermined color.

Images