Discharge position correction method and printer

Abstract

To impact droplets injected from a head at a suitable position.SOLUTION: A discharge position correction method arranges a head at a discharge position corresponding to each of a plurality of object positions spaced from each other by each prescribed distance from a reference position of a placement surface in a sub-scanning direction in the state that a medium is placed on the placement surface, and discharges the droplets while relatively moving a table and the head in a main scanning direction along the placement surface at each object position, thereby printing a plurality of adjustment patterns arranged in the sub-scanning direction on the medium; determines a deviation amount in the sub-scanning direction for each object position with respect to the plurality of adjustment patterns on the basis of a positional relationship between the adjustment patterns of the plurality of adjustment patterns, which are adjacent to each other in the sub-scanning direction; calculates a correction amount of the discharge position in the sub-scanning direction at each of the plurality of object positions on the basis of the determined deviation amount; during a printing operation, corrects the discharge position corresponding to the plurality of object positions on the basis of the calculated correction amount; and arranges the head at the discharge position after correction.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a method for correcting ejection positions and a printing apparatus. [Background technology]

[0002] Known printing devices that print on media include inkjet printing devices that eject droplets from a head onto the media (see, for example, Patent Document 1). Such printing devices include, for example, a table on which the media can be placed, and a head that ejects droplets toward the surface of the media while moving back and forth in the main scanning direction above the table. This printing device ejects droplets while moving the head in the main scanning direction, then moves the head a predetermined distance in the sub-scanning direction that intersects the main scanning direction, and then again moves back and forth in the main scanning direction and ejects droplets. By repeating this operation, an image is formed across the entire media, one row or multiple rows at a time. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-109360 Summary of the Invention [Problem to be solved by the invention]

[0004] In the printing device described above, the head is supported on a table. When the head is moved in the sub-scanning direction, the tilt of the head relative to the table changes depending on the position of the head in the sub-scanning direction, which can cause droplets ejected from the head to land in positions that are different from the intended landing positions.

[0005] The present invention has been made in view of the above, and has an object to provide an ejection position correction method and a printing apparatus that are capable of causing droplets ejected from a head to land in appropriate positions. [Means for solving the problem]

[0006] The ejection position correction method according to the present invention is a method for correcting the ejection position of the head relative to the table in the sub-scanning direction in a printing device that includes: a table having a mounting surface on which a medium is placed; a head having a nozzle surface facing the mounting surface and having a plurality of nozzles formed thereon, the head ejecting droplets from the plurality of nozzles toward the mounting surface; a relative movement mechanism that moves the table and the head relatively in a main scanning direction and a sub-scanning direction along the mounting surface; and a control unit that controls the relative movement between the table and the head by the relative movement mechanism and the ejection of the droplets by the head to perform a printing operation in which the droplets are ejected toward the medium placed on the mounting surface, the method comprising: correcting the ejection position of the head relative to the table in the sub-scanning direction, the method comprising: and discharging the droplets while moving the table and the head relatively in the main scanning direction along the placement surface for each of the target positions, thereby printing a plurality of adjustment patterns lined up in the sub-scanning direction on the medium; a deviation amount detection step of detecting a deviation amount in the sub-scanning direction for each of the plurality of adjustment patterns from the target position based on a positional relationship between adjacent adjustment patterns in the sub-scanning direction among the plurality of adjustment patterns; a correction amount calculation step of calculating a correction amount for the ejection position in the sub-scanning direction for each of the plurality of target positions based on the deviation amount thus determined; and a correction step of correcting the ejection positions corresponding to the plurality of target positions based on the calculated correction amount during the printing operation, and disposing the head at the corrected ejection positions.

[0007] The printing device according to this embodiment includes a table having a mounting surface on which a medium is placed, a head having a nozzle surface facing the mounting surface and having a plurality of nozzles formed thereon, and ejecting droplets from the plurality of nozzles toward the mounting surface, a relative movement mechanism that moves the table and the head relatively in a main scanning direction and a sub-scanning direction along the mounting surface, and a control unit that controls the relative movement between the table and the head by the relative movement mechanism and the ejection of the droplets by the head, to perform a printing operation in which the droplets are ejected toward the medium placed on the mounting surface, and the control unit controls, with the medium placed on the mounting surface, ejection positions corresponding to a plurality of target positions spaced apart by a predetermined distance in the sub-scanning direction from a reference position on the mounting surface. and a memory unit that stores an amount of deviation in the sub-scanning direction for each of a plurality of adjustment patterns from the target position, based on a positional relationship between adjacent adjustment patterns in the sub-scanning direction, among a plurality of adjustment patterns that are arranged in the sub-scanning direction and printed on the medium by discharging the droplets while moving the table and the head relatively in the main scanning direction along the mounting surface for each of the target positions; and a processing unit that calculates an amount of correction of the ejection position in the sub-scanning direction for each of the plurality of target positions based on the amount of deviation stored in the memory unit, corrects the ejection positions corresponding to the plurality of target positions based on the calculated correction amount during the printing operation, and positions the head at the corrected ejection positions. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide an ejection position correction method and a printing apparatus that are capable of causing droplets ejected from a head to land in appropriate positions. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram (perspective view) showing an example of the schematic configuration of a printing apparatus according to this embodiment. [Figure 2] FIG. 2 is a diagram (plan view) showing an example of the schematic configuration of a printing device according to this embodiment. [Figure 3] FIG. 3 is a diagram (viewed from the +Y side) showing an example of the schematic configuration of a printing apparatus according to this embodiment. [Figure 4] FIG. 4 is a diagram (viewed from the +X side) showing an example of the schematic configuration of a printing apparatus according to this embodiment. [Figure 5] FIG. 5 is a flowchart showing an example of the ejection position correction method according to this embodiment. [Figure 6] FIG. 6 is a diagram illustrating an example of the operation of printing an adjustment pattern on a medium. [Figure 7] FIG. 7 is a diagram showing an example of an adjustment pattern formed on a medium. [Figure 8] FIG. 8 is a diagram illustrating an example of a deviation amount table stored in the storage unit. [Figure 9] FIG. 9 is a diagram illustrating an example of a printing operation. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of a method for correcting ejection position and a printing apparatus according to the present invention will be described with reference to the accompanying drawings. Note that the present invention is not limited to these embodiments. Furthermore, the components in the following embodiments include those that are easily replaceable by those skilled in the art, or those that are substantially the same.

[0011] In this embodiment, directions in the drawings are explained using an XYZ coordinate system. In this XYZ coordinate system, a plane parallel to the floor on which the printing device 100 is placed is defined as the XY plane. In this XY plane, the main scanning direction, which is the direction of head movement, is referred to as the Y direction, and the direction perpendicular to the X direction on the XY plane is referred to as the X direction. The direction perpendicular to the XY plane (height direction) is referred to as the Z direction. The X, Y, and Z directions are explained assuming that the direction of the arrow in the drawing is the + direction and the direction opposite to the arrow is the - direction. In this embodiment, the +X direction may be referred to as the front direction (front side), the -X direction as the rear direction (rear side), the +Y direction as the left (left side), the -Y direction as the right (right side), the +Z direction as the up (upper side), and the -Z direction as the down (lower side).

[0012] 1 to 4 are diagrams showing an example of the schematic configuration of a printing device 100 according to this embodiment. FIG. 1 is a perspective view, FIG. 2 is a plan view, FIG. 3 is a view from the +Y side, and FIG. 4 is a view from the +X side. As shown in FIGS. 1 to 4, in this embodiment, the printing device 100 will be described as an image forming device that forms an image on a medium M such as a film or plate material. As shown in FIG. 1, the printing device 100 includes a table 10, a head 20, a head moving mechanism 30, and a control unit 40.

[0013] The table 10 supports the media M and the head moving mechanism 30. The table 10 has a mounting surface 10a on which the media M is placed. The table 10 has a plurality of top plate members 11 and a support portion 12.

[0014] The top panel member 11 is a rectangular plate. A plurality of top panel members 11 are connected and arranged in the X direction. The table 10 is configured such that the length of the table 10 is in the X direction by connecting the plurality of top panel members 11 in the X direction. The plurality of top panel members 11 are arranged so that the placement surfaces 11a of each are flush with each other.

[0015] The top panel members 11 have positioning portions 13 on opposing surfaces 11f that face each other in the X direction. The positioning portions 13 have, for example, a recessed portion 13a provided on one of the top panel members 11 and a protruding portion 13b provided on the other top panel member 11. The positioning portions 13 position the top panel members 11 in the Y and Z directions by inserting the protruding portion 13b into the recessed portion 13a. Furthermore, by positioning the top panel members 11 relative to each other by the positioning portions 13, members that are provided across multiple top panel members 11, such as X guide portions 36a and 36b (described below) provided on the top panel members 11, are also positioned relative to each other.

[0016] As shown in FIGS. 1 to 3, the support portion 12 supports the tabletop member 11. The support portion 12 has a plurality of legs 12a, 12b. The plurality of legs 12a, 12b are arranged side by side in the X direction along both Y-direction edges of the tabletop member 11. The plurality of legs 12a are supported by a floor portion F. The plurality of legs 12b may be configured to be supported by the floor portion F, or may be configured to be supported by connecting members 12c that connect the plurality of legs 12a to each other. When the plurality of legs 12b are connected to the connecting members 12c, they may be configured to be fixed by welding, or may be configured to be fastened with fastening members such as bolts.

[0017] The head 20 has a nozzle surface 21 facing the mounting surface 11a. The nozzle surface 21 is, for example, planar. The nozzle surface 21 is provided with a plurality of nozzles (not shown) that eject ink. Examples of the ink include ultraviolet-curable ink. The ultraviolet-curable ink may be white ink, colored inks such as cyan (C), magenta (M), yellow (Y), and black (K), or transparent ink, depending on the color of the image to be formed on the medium M. The head 20 is electrically connected to a control unit 40, and its drive is controlled by the control unit 40. The head 20 is connected to an ink supply device (not shown) and receives ink from the ink supply device. The head 20 is movable in the main scanning direction together with a carriage 22. The head 20 ejects ink toward the mounting surface 11a while moving back and forth along the main scanning direction. In the case where the head 20 is configured to eject ultraviolet curable ink, the carriage 22 is equipped with an ultraviolet irradiation device (not shown) that irradiates the ultraviolet curable ink with ultraviolet rays.

[0018] The head moving mechanism 30 is supported by the table 10, and moves the head 20 in the X and Y directions along the mounting surface 10a of the table 10. The head moving mechanism 30 moves the head 20 in the X and Y directions relative to the table 10, thereby moving the table 10 and the head 20 relatively. The head moving mechanism 30 has a main scanning moving unit 31 and a sub-scanning moving unit 32.

[0019] Main scanning movement unit 31 has a Y bar 33, a Y slider 34, and a Y drive unit 35. Y bar 33 is arranged parallel to the Y direction. Y bar 33 guides carriage 22 in the Y direction. Y bar 33 is supported by sub-scanning movement unit 32. Y slider 34 is provided on carriage 22 and slides in the Y direction along Y bar 33. Y drive unit 35 moves Y slider 34 in the Y direction. Y drive unit 35 has a drive source such as a motor, and a transmission mechanism such as a belt that transmits the drive force of the drive source to Y slider 34.

[0020] Sub-scanning movement unit 32 has X guides 36, X sliders 37, and X drive units 38. X guides 36 are provided on both side surfaces 11e of tabletop member 11 in the Y direction. X guides 36 extend in the X direction and are arranged so as to straddle both sides of multiple tabletop members 11 in the X direction. Specifically, X guide portions 36a arranged on both side surfaces 11e of one tabletop member 11 and X guide portions 36b arranged on both side surfaces 11e of another tabletop member 11 are connected in the X direction. X slider 37 is provided on carriage 22 and slides in the X direction along X guides 36. X drive unit 38 moves X slider 37 in the X direction. X drive unit 38 has a drive source such as a motor and a transmission mechanism such as a belt that transmits the drive force of the drive source to X slider 37.

[0021] The control unit 40 comprehensively controls the operation of the printing device 100. The control unit 40 controls the relative movement between the table 10 and the head 20 and the ejection of droplets by the head 20, thereby performing a printing operation in which droplets are ejected toward the medium placed on the placement surface 10a. The control unit 40 has a communication unit 41, a processing unit 42, and a memory unit 43.

[0022] The communication unit 41 performs wired or wireless communication with an external device and includes an interface such as a network interface card.

[0023] The processing unit 42 performs various types of information processing. The processing unit 42 includes a processor such as a CPU (Central Processing Unit) that functions as a controller that executes various types of processing, and a memory such as a ROM (Read Only Memory) or RAM (Random Access Memory) that functions as a memory that stores various types of information.

[0024] The processing unit 42 performs processing related to the operation of the head 20. The processing by the processing unit 42 causes ink to be ejected from the nozzles of the head 20. The processing by the processing unit 42 also causes ultraviolet light to be emitted from the ultraviolet light irradiation device.

[0025] Processing unit 42 performs processing related to the operation of head movement mechanism 30. Through the processing of processing unit 42, Y slider 34 is driven by Y drive unit 35, and carriage 22 moves in the Y direction, which is the main scanning direction. Furthermore, through the processing of processing unit 42, X slider 37 is driven by X drive unit 38, and main scanning movement unit 31 and carriage 22 move in the X direction, which is the sub-scanning direction. For example, a program or the like that defines the movement speed, movement direction, movement timing, etc. of Y slider 34 and X slider 37 can be created in advance and stored in a storage unit, and head movement mechanism 30 can execute the program to control the movement of Y slider 34 and X slider 37.

[0026] The storage unit 43 stores information such as various programs and data. In this embodiment, the storage unit 43 stores the amount of deviation of an adjustment pattern, which will be described later. The storage unit 43 includes storage such as an HDD (Hard Disk Drive) or SSD (Solid State Drive).

[0027] In the control unit 40, the processor in the processing unit 42 reads out various programs and loads them into memory, thereby executing information processing corresponding to the functions of the above-mentioned units. Examples of the various programs include programs received by the communication unit 41, programs stored in the storage unit 43, and programs recorded on an external recording medium. The control unit 40 functions as an information processing device (computer) that executes various information processes. Note that the various programs may be executed by an information processing device other than the control unit 40, or the control unit 40 and the other information processing device may cooperate to execute the various programs.

[0028] In the printing device 100, when the head 20 is moved in the X direction, the inclination of the head 20 (nozzle surface 21) relative to the table 10 may change depending on the position of the head 20 in the X direction. In this case, droplets ejected from the head 20 may land at positions that are shifted from their intended landing positions. Therefore, in the printing device 100 according to this embodiment, when a printing operation is performed, the ejection position of the head 20 relative to the table 10 is corrected in the X direction (sub-scanning direction). The ejection position correction method according to this embodiment will be described below.

[0029] 5 is a flowchart showing an example of a method for correcting ejection positions according to this embodiment. The method for correcting ejection positions includes an adjustment pattern printing step S10, a deviation amount detection step S20, a correction amount calculation step S30, and a correction step S40.

[0030] In the adjustment pattern printing step S10, an adjustment pattern is printed on the medium. Fig. 6 is a diagram schematically illustrating an example of the operation of printing an adjustment pattern on the medium. In the adjustment pattern printing step S10, the medium M is placed on the mounting surface 11a as shown in Fig. 6. In this state, the head 20 is placed at each of ejection positions Q (Q1, Q2, ..., QN (N is a natural number)) corresponding to a plurality of target positions P (P1, P2, ..., PN (N is a natural number)) spaced at predetermined distances d in the X direction from the reference position O on the mounting surface 11a, and droplets are ejected for each target position P while the table 10 and the head 20 are moved relatively in the Y direction along the mounting surface 11a.

[0031] This operation prints multiple adjustment patterns R (R1, R2, ... RN (N is a natural number)) aligned in the X direction on the medium. In this embodiment, N is, for example, 11. The value of N is not limited to 11. The multiple target positions P are arranged so as to straddle the connection portions of the tables 10 in the X direction.

[0032] 7 is a diagram showing an example of an adjustment pattern formed on a medium. As shown in FIG. 7, the adjustment pattern R includes an adjustment portion Ra and a reference portion Rb. The adjustment portion Ra is located on the upstream side in the X direction. The reference portion Rb is located on the downstream side in the X direction, spaced a predetermined distance d from the adjustment portion Ra.

[0033] In this embodiment, the adjustment portion Ra and the reference portion Rb are, for example, straight lines parallel to the Y direction. The adjustment portion Ra and the reference portion Rb have different lengths in the Y direction. In this embodiment, the reference portion Rb is longer in the Y direction than the adjustment portion Ra. The adjustment portion Ra may be longer in the Y direction than the reference portion Rb. The adjustment portion Ra and the reference portion Rb may be different colors. Note that the adjustment portion Ra and the reference portion Rb are not limited to straight lines and may have other shapes such as curves, dashed lines, or planar figures. In FIG. 7, to make it easier to distinguish between the adjustment portion Ra and the reference portion Rb, the adjustment portion Ra is shown with a solid line and the reference portion Rb is shown with a dashed line.

[0034] In the adjustment pattern R, the adjustment portion Ra and the reference portion Rb are spaced a predetermined distance d in the X direction. Each adjustment pattern R is formed by moving the head 20 the predetermined distance d in the X direction. Therefore, the second and subsequent adjustment patterns R are formed so that the target position of the adjustment portion Ra overlaps with the reference portion Rb of the adjustment pattern R formed immediately before.

[0035] When the inclination of the head 20 relative to the table 10 does not change, as shown in the detection portion A of Figure 7, the adjustment pattern R is formed so that the adjustment portion Ra of the adjustment patterns R2 to R11 overlaps with the reference portion Rb of the adjustment patterns R1 to R10 formed one before, at the center in the X direction.

[0036] Furthermore, when the inclination of the head 20 relative to the table 10 changes, the adjustment pattern R is formed so that the adjustment portion Ra of the adjustment patterns R2 to R11 is shifted in the +X direction or the -X direction relative to the reference portion Rb of the adjustment pattern R1 to R10 formed one before, as shown in the detection portions B and C of Figure 7.

[0037] In the deviation amount detection step S20, the deviation amount in the X direction from the target position P for each of the plurality of adjustment patterns R is determined based on the positional relationship between adjacent adjustment patterns R in the X direction among the plurality of adjustment patterns R.

[0038] For example, as shown in detection portion A in FIG. 7, when the adjustment portion Ra of the adjustment patterns R6 to R11 overlaps with the reference portion Rb of the adjustment patterns R5 to R10 formed immediately before in the center in the X direction, the amount of deviation is 0.

[0039] Furthermore, as shown in detection portion B in Figure 7, when the adjustment portion Ra of adjustment patterns R2 and R5 is shifted in the +X direction relative to the reference portion Rb of the adjustment patterns R1 and R4 formed one before, the amount of shift will be a positive value.

[0040] Furthermore, as shown in the detection portion C in Figure 7, when the adjustment portion Ra of the adjustment patterns R3 and R4 is shifted in the -X direction relative to the reference portion Rb of the adjustment patterns R2 and R3 formed one before, the amount of shift will be a negative value.

[0041] When detecting the amount of misalignment, for example, an image of the adjustment pattern R formed on the medium M is acquired by an image acquisition unit such as a camera or scanner, and the acquired image is subjected to image processing, etc., thereby detecting the amount of misalignment. For example, an operator inputs the detected amount of misalignment into the printing device 100 in association with the target position P, and a misalignment amount table in which the target position P is associated with the amount of misalignment is stored in the storage unit 43.

[0042] FIG. 8 is a diagram showing an example of a deviation amount table stored in the storage unit 43. In the example shown in FIG. 8, in addition to target positions P1 to P11 where adjustment patterns R were ejected, a column for target position P12, which is the last target position on the +X side of target position P11, is provided. The target position is an X coordinate with reference position O as the origin, measured in μm. The deviation amount is a value obtained by subtracting the X coordinate of the reference portion Rb of the adjustment pattern R on the -X side from the X coordinate of the adjustment portion Ra of the adjustment pattern R on the +X side for two adjacent adjustment patterns R, measured in μm. As shown in FIG. 8, the target positions P and deviation amounts are stored in association with each other. Note that in this example, the deviation amount corresponding to target position P1 on the farthest -X side, where no overlapping of two adjustment patterns R is formed, and the deviation amount corresponding to target position P12 on the farthest +X side are both set to 0. This setting improves the accuracy of linear interpolation.

[0043] In the correction amount calculation step S30, the correction amount of the ejection position Q of the head 20 in the X direction is calculated for each of the multiple target positions P based on the relationship between the target position P and the deviation amount stored in the memory unit 43. Here, the correction amount is the amount by which the ejection position Q of the head 20 is changed in the +X direction or the -X direction.

[0044] If the amount of deviation detected in deviation amount detection step S20 is 0, it means that the droplets ejected from the head 20 at the ejection positions Q6 to Q11 have landed on the target positions P6 to P11.

[0045] If the amount of deviation detected in deviation amount detection step S20 is a positive value, it means that the droplets ejected from the head 20 at ejection positions Q2 and Q5 landed at positions shifted toward the +X side from the target positions P2 and P5. Therefore, in this case, the processing unit 42 calculates a correction value for shifting the ejection positions Q2 and Q5 toward the -X side so that the adjustment portions Ra of the adjustment patterns R2 and R5 and the reference portions Rb of the previous adjustment patterns R1 and R4 overlap at their centers in the X direction.

[0046] If the amount of deviation detected in deviation amount detection step S20 is a negative value, it means that the droplets ejected from the head 20 at ejection positions Q3 and Q4 landed at positions that are shifted toward the -X side from the target positions P3 and P4. Therefore, in this case, the processing unit 42 calculates a correction value to shift the ejection positions Q3 and Q4 toward the +X side so that the adjustment portions Ra of the adjustment patterns R3 and R4 and the reference portions Rb of the previous adjustment patterns R2 and R3 overlap at their centers in the X direction.

[0047] The processing unit 42 associates the correction value obtained as described above with the target position P and stores it in the storage unit 43.

[0048] After performing the correction value calculation step S30, the adjustment pattern printing step S10 may be performed again to form the adjustment pattern R at the corrected ejection position Q' corrected with the correction value, and the deviation amount detection step S20 and the correction amount calculation step S30 may be performed again based on the adjustment pattern R. In this case, the correction amount can be updated based on the calculation result calculated again in the correction amount calculation step S30.

[0049] 9 is a diagram schematically illustrating an example of a printing operation. As shown in FIG. 9, in a correction step S40, during printing, ejection positions Q corresponding to multiple target positions P are corrected based on the calculated correction amount. The X coordinate of the corrected ejection position Q' is the value obtained by adding the correction value to the X coordinate of the ejection position Q before correction (the same as the X coordinate of the target position P). The processing unit 42 positions the head 20 at the corrected ejection position Q', and from this state controls the movement of the head 20 by the head movement mechanism 30 and the ejection of droplets by the head 20 to eject droplets toward the medium M placed on the mounting surface 10a. By ejecting droplets from the head 20 at the corrected ejection position Q', it is possible to land the droplets S at appropriate positions.

[0050] As described above, the ejection position correction method according to this embodiment is a method for correcting the ejection position of the head 20 relative to the table 10 in the sub-scanning direction in a printing device that includes: a table 10 having a mounting surface 11a on which a medium is placed; a head 20 having a nozzle surface 21 facing the mounting surface 11a and having a plurality of nozzles formed thereon, the head 20 ejecting droplets from the plurality of nozzles toward the mounting surface 11a; a head moving mechanism 30 that moves the table 10 and the head 20 relatively in the main scanning direction and the sub-scanning direction along the mounting surface 11a; and a control unit 40 that controls the relative movement of the table 10 and the head 20 by the head moving mechanism 30 and the ejection of droplets by the head 20 to perform a printing operation in which droplets are ejected toward the medium placed on the mounting surface 11a, and the head 20 is disposed at ejection positions corresponding to a plurality of target positions spaced at intervals of 10 mm, and droplets are ejected while the table 10 and the head 20 are moved relatively in the main scanning direction along the mounting surface 11a for each target position, thereby printing a plurality of adjustment patterns lined up in the sub-scanning direction on the medium; a deviation amount calculation step S20 is performed to calculate the amount of deviation in the sub-scanning direction for each of the plurality of adjustment patterns from the target position based on the positional relationship between adjacent adjustment patterns in the sub-scanning direction among the plurality of adjustment patterns; a correction amount calculation step S30 is performed to calculate the amount of correction of the ejection position in the sub-scanning direction for each of the plurality of target positions based on the determined deviation amount; and a correction step S40 is performed to correct the ejection positions corresponding to the plurality of target positions based on the calculated correction amount during the printing operation, and to position the head 20 at the corrected ejection positions.

[0051] According to this configuration, multiple adjustment patterns R aligned in the X direction are printed on the medium, and the amount of deviation in the X direction from the target position P is calculated for each of the multiple adjustment patterns R based on the positional relationship between adjacent adjustment patterns R in the X direction, and the amount of correction for the ejection position in the X direction is calculated for each of the multiple target positions P based on the amount of deviation, and the ejection position Q during the printing operation is corrected based on the calculated correction amount. This makes it possible to cause droplets ejected from the head 20 to land in appropriate positions.

[0052] In the ejection position correction method according to this embodiment, the table 10 has a plurality of top plate members 11 connected in the X direction, and a plurality of target positions P are arranged so as to straddle the connection portions 14 between the top plate members 11 in the X direction.

[0053] According to this configuration, when the inclination of the head 20 relative to the table 10 changes in the X direction within a range spanning the connection portion 14 between the top plate members 11, it is possible to make the droplets ejected from the head 20 land at appropriate positions.

[0054] In the ejection position correction method according to this embodiment, the adjustment pattern R includes an adjustment portion Ra that is arranged on the upstream side (+X side) of the X direction, and a reference portion Rb that is arranged a predetermined distance from the reference portion Rb on the downstream side (-X side) of the X direction.

[0055] According to this configuration, in the adjustment pattern R, the adjustment portion Ra and the reference portion Rb are spaced a predetermined distance d in the X direction, and each adjustment pattern R is formed by moving the head 20 the predetermined distance d in the X direction. As a result, the second and subsequent adjustment patterns R formed in the X direction are formed so that the target position of the adjustment portion Ra is the reference portion Rb of the previously formed adjustment pattern R, making it easier to detect the positional relationship between adjacent adjustment patterns R in the X direction.

[0056] In the ejection position correction method according to this embodiment, the adjustment portion Ra and the reference portion Rb are straight lines parallel to the main scanning direction.

[0057] According to this configuration, the amount of droplets consumed when forming the adjustment portion Ra and the reference portion Rb can be reduced.

[0058] In the ejection position correction method according to this embodiment, the adjustment portion Ra and the reference portion Rb have different lengths in the main scanning direction.

[0059] This configuration allows the operator to easily distinguish between the adjustment portion Ra and the reference portion Rb.

[0060] The printing device 100 according to this embodiment includes a table 10 having a mounting surface 11a on which a medium is placed, a head 20 having a nozzle surface 21 facing the mounting surface 11a and having a plurality of nozzles formed thereon, and ejecting droplets from the plurality of nozzles toward the mounting surface 11a, a head movement mechanism 30 that moves the table 10 and the head 20 relatively in the main scanning direction and sub-scanning direction along the mounting surface 11a, and a control unit 40 that controls the relative movement of the table 10 and the head 20 by the head movement mechanism 30 and the ejection of droplets by the head 20 to perform a printing operation in which droplets are ejected toward the medium placed on the mounting surface 11a, and the control unit 40 controls the head 20 to eject droplets at predetermined intervals in the sub-scanning direction from a reference position on the mounting surface 11a with the medium placed on the mounting surface 11a. The head 20 is positioned at each of the ejection positions corresponding to the plurality of vacant target positions, and droplets are ejected while the table 10 and the head 20 are moved relatively in the main scanning direction along the mounting surface 11a for each target position to print a plurality of adjustment patterns arranged in the sub-scanning direction on the medium, and based on the positional relationship between adjacent adjustment patterns in the sub-scanning direction, a memory unit 43 stores an amount of deviation in the sub-scanning direction for each of the plurality of adjustment patterns from the target position; and a processing unit 42 calculates an amount of correction of the ejection position in the sub-scanning direction for each of the plurality of target positions based on the amount of deviation stored in the memory unit 43, corrects the ejection positions corresponding to the plurality of target positions based on the calculated correction amount during the printing operation, and positions the head 20 at the corrected ejection position.

[0061] According to this configuration, multiple adjustment patterns R aligned in the X direction are printed on the medium, and the amount of deviation in the X direction from the target position P is calculated for each of the multiple adjustment patterns R based on the positional relationship between adjacent adjustment patterns R in the X direction, and the amount of correction for the ejection position in the X direction is calculated for each of the multiple target positions P based on the amount of deviation, and the ejection position Q during the printing operation is corrected based on the calculated correction amount. This makes it possible to cause droplets ejected from the head 20 to land in appropriate positions.

[0062] The technical scope of the present invention is not limited to the above-described embodiment, and appropriate modifications can be made without departing from the spirit of the present invention. For example, in the above-described embodiment, a configuration in which the table 10 and the head 20 are moved relative to each other by moving the head 20 relative to the table 10 has been described as an example, but the present invention is not limited to this configuration. For example, a configuration in which the table 10 and the head 20 are moved relative to each other by moving the table 10 relative to the head 20 may also be used.

[0063] In the above embodiment, the configuration in which the multiple target positions P are arranged so as to straddle the connection portions 14 of the table top members 11 in the X direction has been described as an example, but the configuration is not limited to this. The multiple target positions P may be arranged so as not to straddle the connection portions 14 of the table top members 11. Furthermore, the table 10 may be configured not to have multiple table top members 11. [Explanation of symbols]

[0064] A, B, C...detection part, F...floor part, M...media, O...reference position, P, P to P12...target position, R, R1 to R11...adjustment pattern, Ra...adjustment part, Rb...reference part, Q, Q1 to Q11...discharge position, S...droplet, 10...table, 10a, 11a...mounting surface, 11...top plate member, 11e...side surface, 11f...opposing surface, 12...support part, 12a, 12b...legs, 12c...connecting member, 13...positioning part, 1 3a...concave portion, 13b...convex portion, 14...connecting portion, 20...head, 21...nozzle surface, 22...carriage, 30...head moving mechanism, 31...main scanning moving portion, 32...sub-scanning moving portion, 33...Y bar, 34...Y slider, 35...Y driving portion, 36...X guide, 36a, 36b...X guide portion, 37...X slider, 38...X driving portion, 40...control portion, 41...communication portion, 42...processing portion, 43...storage portion, 100...printing device

Claims

1. a table having a mounting surface on which a medium is placed; a head having a nozzle surface facing the mounting surface and having a plurality of nozzles formed thereon, the head discharging droplets from the plurality of nozzles toward the mounting surface; a relative movement mechanism that moves the table and the head relatively in a main scanning direction and a sub-scanning direction along the mounting surface; a control unit that controls the relative movement between the table and the head by the relative movement mechanism and the ejection of the droplets by the head, thereby performing a printing operation in which the droplets are ejected toward the medium placed on the placement surface; a discharge position correction method for correcting a discharge position of the head relative to the table in the sub-scanning direction in a printing apparatus comprising: an adjustment pattern printing step of disposing the head at each of a plurality of target positions spaced at predetermined distances in the sub-scanning direction from a reference position on the mounting surface while the medium is mounted on the mounting surface, and discharging the droplets while moving the table and the head relatively in the main scanning direction along the mounting surface for each target position, thereby printing a plurality of adjustment patterns arranged in the sub-scanning direction on the medium; a deviation amount detection step of detecting a deviation amount in the sub-scanning direction for each of the plurality of adjustment patterns relative to the target position based on a positional relationship between adjacent adjustment patterns in the sub-scanning direction among the plurality of adjustment patterns; a correction amount calculation step of calculating a correction amount of the ejection position in the sub-scanning direction for each of the plurality of target positions based on the calculated deviation amount; a correction step of correcting the ejection positions corresponding to the plurality of target positions based on the calculated correction amount during the printing operation, and disposing the head at the corrected ejection positions; A method for correcting a discharge position, comprising:

2. the table has a plurality of top plate members connected in the sub-scanning direction, The plurality of target positions are arranged so as to straddle the connecting portions of the top plate members in the sub-scanning direction. The ejection position correction method according to claim 1 .

3. The adjustment pattern includes an adjustment portion disposed on the upstream side in the sub-scanning direction, and a reference portion disposed on the downstream side in the sub-scanning direction at the predetermined distance from the adjustment portion. The ejection position correction method according to claim 1 .

4. The adjustment pattern and the reference portion are straight lines parallel to the main scanning direction. The ejection position correction method according to claim 3 .

5. The adjustment pattern and the reference portion have different lengths in the main scanning direction. The ejection position correction method according to claim 4 .

6. a table having a mounting surface on which a medium is placed; a head having a nozzle surface facing the mounting surface and having a plurality of nozzles formed thereon, the head discharging droplets from the plurality of nozzles toward the mounting surface; a relative movement mechanism that moves the table and the head relatively in a main scanning direction and a sub-scanning direction along the mounting surface; a control unit that controls the relative movement between the table and the head by the relative movement mechanism and the ejection of the droplets by the head, thereby performing a printing operation in which the droplets are ejected toward the medium placed on the placement surface; Equipped with The control unit a storage unit that, with the medium placed on the placement surface, disposes the head at ejection positions corresponding to a plurality of target positions spaced at predetermined distances in the sub-scanning direction from a reference position on the placement surface, and ejects the droplets while moving the table and the head relatively along the placement surface in the main scanning direction for each of the target positions to print a plurality of adjustment patterns aligned in the sub-scanning direction onto the medium, and stores an amount of deviation in the sub-scanning direction for each of the plurality of adjustment patterns from the target positions based on a positional relationship between the adjustment patterns adjacent in the sub-scanning direction; a processing unit that calculates a correction amount of the ejection position in the sub-scanning direction for each of the plurality of target positions based on the deviation amount stored in the storage unit, corrects the ejection positions corresponding to the plurality of target positions based on the calculated correction amount during the printing operation, and positions the head at the corrected ejection positions; A printing device having:

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