Printing apparatus

Abstract

To provide a printing apparatus that can reduce the risk of increased media consumption and the time required to detect adjustment images. [Solution] The printing apparatus comprises a printing unit 12 that prints a job image A1 and an adjustment image B1 onto a medium 99, the printing unit having a head for ejecting liquid onto the medium and a carriage 17 on which the head is mounted and which moves in the scanning direction X1 relative to the medium, a detection unit 22 mounted on the carriage for detecting an adjustment image including one or more adjustment patterns P1, a transport unit 19 that transports the medium relative to the printing unit in a transport direction Y1 different from the scanning direction, and a control unit that adjusts the liquid ejection timing based on the detection result of the adjustment image by the detection unit, the control unit prints the adjustment image by the printing unit such that it is aligned with the job image in the scanning direction and the distance to the upstream end A3 of the job image is smaller than the distance to the downstream end A2 of the job image in the transport direction.

Description

[[Technical Field]]

[0001] The present invention relates to a printing apparatus. [[Background Art]]

[0002] Patent Document 1 describes a printing apparatus including a printing unit that prints a job image on a medium by ejecting liquid onto the medium while scanning the medium. The printing apparatus is configured to print an adjustment image including one or more adjustment patterns in order to align the landing position of liquid ejected from the printing unit at a first ejection timing with the landing position of liquid ejected from the printing unit at a second ejection timing. The printing apparatus adjusts the first ejection timing and the second ejection timing by detecting the adjustment image. [[Prior Art Documents]] [[Patent Documents]]

[0003] [[Patent Document 1]] Japanese Patent Application Laid-Open No. 2012-210773 [[Summary of the Invention]] [[Problem to be Solved by the Invention]]

[0004] In such a printing apparatus, when the adjustment image is printed so as to be aligned with the job image in the conveyance direction of the medium, the medium consumption tends to increase. In contrast, when the adjustment image is printed so as to be aligned with the job image in the scanning direction of the printing unit, it is necessary to suppress an increase in the time required for detecting the adjustment image. [[Means for Solving the Problem]]

[0005] A printing apparatus for solving the above problems is a printing unit for printing a job image and an adjustment image on a medium, the printing unit having a head for ejecting liquid onto the medium and a carriage on which the head is mounted and which moves in the scanning direction relative to the medium; a detection unit mounted on the carriage for detecting the adjustment image which includes one or more adjustment patterns; a transport unit for transporting the medium relative to the printing unit in a transport direction different from the scanning direction; and a control unit for adjusting the liquid ejection timing based on the detection result of the adjustment image by the detection unit, wherein the control unit prints the adjustment image by the printing unit such that it is aligned with the job image in the scanning direction and the distance to the upstream end of the job image is smaller than the distance to the downstream end of the job image in the transport direction. [Brief explanation of the drawing]

[0006] [Figure 1] Figure 1 is a schematic diagram showing one embodiment of a printing apparatus. [Figure 2] Figure 2 is a bottom view of the head showing the nozzle surface. [Figure 3] Figure 3 shows the layout of the job image, adjustment image, and check image. [Figure 4] Figure 4 shows an example of an adjustment pattern. [Figure 5] Figure 5 shows an example of an adjusted image. [Figure 6] Figure 6 shows the layout of this adjustment image. [Figure 7] Figure 7 is a flowchart showing an example of the printing process. [Modes for carrying out the invention]

[0007] The following describes an embodiment of a printing device with reference to the diagram. The printing device is an inkjet printer that prints images such as characters and photographs by ejecting ink, which is an example of a liquid, onto a medium such as paper, fabric, or film.

[0008] <Printing device> As shown in Figure 1, the printing device 10 includes a housing 11. The housing 11 houses the various components of the printing device 10.

[0009] The printing apparatus 10 includes a printing unit 12. The printing unit 12 is configured to print an image onto a medium 99. More specifically, the printing unit 12 prints an image onto the medium 99 by discharging a liquid onto the medium 99. The printing unit 12 may dispense a liquid containing not only ink, but also particles of functional materials such as electrode materials and pixel materials dispersed, mixed, or dissolved in the liquid.

[0010] The printing unit 12 has a head 13. The head 13 is configured to discharge liquid onto a medium 99. The head 13 has a nozzle surface 15 on which one or more nozzles 14 are provided. In one example, the head 13 has multiple nozzles 14 opening on the nozzle surface 15. The nozzle surface 15 faces the medium 99. The head 13 discharges liquid from the nozzles 14.

[0011] As shown in Figure 2, the multiple nozzles 14 form one or more nozzle rows 16 on the nozzle surface 15. For example, the multiple nozzles 14 form multiple nozzle rows 16 on the nozzle surface 15. In one example, the multiple nozzles 14 form eight nozzle rows 16 on the nozzle surface 15.

[0012] A nozzle row 16 is formed by multiple nozzles 14 aligned in one direction. In one example, a nozzle row 16 is formed by multiple nozzles 14 aligned in the transport direction Y1. Therefore, the nozzle row 16 extends in the transport direction Y1. The transport direction Y1 is the relative direction in which the medium 99 is transported to the printing unit 12. Multiple nozzle rows 16 are aligned in a direction different from the transport direction Y1. Multiple nozzle rows 16 are aligned in the scanning direction X1. The scanning direction X1 is, for example, a direction that serves as an indicator of the width of the medium 99.

[0013] The printing unit 12 has a carriage 17. The carriage 17 is mounted on a head 13. The carriage 17 is configured to scan against a medium 99. The carriage 17 is configured to move in a scanning direction X1 relative to the medium 99. The carriage 17 is configured to move back and forth along the scanning direction X1. Each back and forth movement of the carriage 17 is called a path. The carriage 17 moves across the medium 99 across its width. When scanning against the medium 99, the carriage 17 moves either a forward path or a return path. In one example, the carriage 17 moves a forward path when moving in the scanning direction X1. The carriage 17 moves a return path when moving in the opposite direction to the scanning direction X1.

[0014] As shown in Figure 1, the printing apparatus 10 includes a support section 18. The support section 18 is configured to support the medium 99. The support section 18 is positioned opposite the printing section 12. The support section 18 is positioned opposite the nozzle surface 15.

[0015] The printing device 10 includes a transport unit 19. The transport unit 19 is configured to transport the medium 99 relative to the printing unit 12 in the transport direction Y1. In one example, the transport unit 19 is configured to transport the medium 99. The transport unit 19 transports the medium 99 in the transport direction Y1. The transport unit 19 may also be configured to move the printing unit 12. For example, the transport unit 19 may be configured to move the printing unit 12 in the opposite direction to the transport direction Y1 relative to the medium 99. In this case, the medium 99 will be transported relative to the printing unit 12. Thus, the printing device 10 may be a flatbed printer using a gantry or the like.

[0016] The conveying section 19 is configured to intermittently convey the medium 99 during printing. That is, the conveying section 19 is configured to repeat conveying and stopping of the medium 99 during printing. For example, the conveying section 19 is configured to convey the medium 99 by a predetermined amount in the conveying direction Y1 every time the printing section 12 reciprocates along the scanning direction X1. For example, the conveying section 19 stops the medium 99 while the printing section 12 reciprocates along the scanning direction X1. For example, the conveying section 19 conveys the medium 99 in the conveying direction Y1 while the printing section 12 is stopped. The conveyance of the medium 99 and the movement of the printing section 12 may be performed such that they partially overlap each other.

[0017] The conveying section 19 may be configured to convey a long medium 99. For example, the conveying section 19 may be configured to convey the medium 99 from a roll body on which the medium 99 is wound. The conveying section 19 may be configured to convey a cut-sheet medium 99. For example, the conveying section 19 may be configured to convey the medium 99 from a cassette, a tray, or the like on which a plurality of media 99 are stacked.

[0018] The conveying section 19 may be configured to reversely convey the medium 99 relative to the printing section 12. That is, the conveying section 19 may be configured to convey the medium 99 relative to the printing section 12 in a direction opposite to the conveying direction Y1. In other words, the conveying section 19 is configured to be capable of executing reverse conveyance that conveys the medium 99 in the direction opposite to the conveying direction Y1. Here, the conveying direction Y1 is a direction in which the medium 99 is intermittently conveyed during printing, and is a direction along the medium 99. In the following description, a position on the side of the conveying direction Y1 relative to any given position is expressed as downstream. Similarly, a position opposite to the conveying direction Y1 relative to any given position is expressed as upstream.

[0019] The conveying unit 19 may include an upper conveying roller 20. The upper conveying roller 20 is positioned so as to be in contact with a medium 99. The upper conveying roller 20 is positioned so as to be in contact with the printing surface of the medium 99 on which printing is performed by the printing unit 12. The upper conveying roller 20 is positioned so as to be in contact with the upper surface of the medium 99. Herein, the upper conveying roller 20 may also be simply referred to as a conveying roller.

[0020] The upper conveying roller 20 is located upstream of the printing unit 12 in the conveying direction Y1. The upper conveying roller 20 is located upstream of the printing unit 12 in the conveying direction Y1 so as not to contact an image printed on the medium 99 during reverse conveying. The upper conveying roller 20 is located upstream of the head 13 in the conveying direction Y1.

[0021] The conveying unit 19 may include a lower conveying roller 21. The lower conveying roller 21 is positioned so as to face the upper conveying roller 20. The upper conveying roller 20 and the lower conveying roller 21 are positioned so as to sandwich the medium 99 therebetween. The lower conveying roller 21 is positioned so as to be in contact with the lower surface of the medium 99. The lower conveying roller 21 is located upstream of the printing unit 12 in the conveying direction Y1. Specifically, the lower conveying roller 21 is located upstream of the head 13 in the conveying direction Y1. The lower conveying roller 21 is rotated by a motor (not shown) and configured to convey the medium 99 in a direction opposite to the conveying direction Y1. In addition, the upper conveying roller 20 rotates following the rotation of the lower conveying roller 21 and the conveyance of the medium 99, thereby stabilizing the conveyance of the medium 99 by the lower conveying roller 21.

[0022] The printing apparatus 10 includes a detection unit 22. The detection unit 22 is attached to the printing unit 12. More specifically, the detection unit 22 is mounted on the carriage 17. The detection unit 22 is positioned to face the medium 99. The detection unit 22 is positioned to face the support unit 18. The detection unit 22 may be positioned in the carriage 17 to be aligned with the head 13. For example, the detection unit 22 is positioned in the carriage 17 to be aligned with the head 13 in the transport direction Y1. In one example, the detection unit 22 is positioned downstream of the head 13 in the transport direction Y1. The detection unit 22 may be positioned upstream of the head 13 in the transport direction Y1. The detection unit 22 may be positioned to overlap with the head 13 in the transport direction Y1. In this case, the detection unit 22 is positioned in the carriage 17 to be aligned with the head 13 in the scanning direction X1.

[0023] The detection unit 22 is configured to detect the adjustment image B1, which will be described later. More specifically, the detection unit 22 is configured to detect the density of the adjustment image B1. The detection unit 22 includes a reflective optical sensor. The detection unit 22 includes a light-emitting element and a light-receiving element. The detection unit 22 detects the adjustment image B1 by irradiating the medium 99 with light and receiving the light reflected from the medium 99.

[0024] The printing device 10 may include a notification unit 23. The notification unit 23 is configured to notify information. The notification unit 23 notifies the user of information by sound, light, or the like. The notification unit 23 is, for example, a display.

[0025] The printing device 10 may include an operation unit 24. The operation unit 24 is configured to receive operations. The operation unit 24 receives operations from the user. The operation unit 24 is, for example, a touch panel.

[0026] The printing device 10 includes a control unit 25. The control unit 25 controls the printing unit 12. The control unit 25 controls the transport unit 19. The control unit 25 controls the detection unit 22. The control unit 25 controls the notification unit 23. The control unit 25 controls the operation unit 24. The control unit 25 comprehensively controls the printing device 10.

[0027] The control unit 25 may consist of one or more processors that perform various processes according to a computer program. The control unit 25 may consist of one or more dedicated hardware circuits, such as ASICs, that perform at least some of the various processes. The control unit 25 may consist of a circuit that includes a combination of processors and hardware circuits. The processor includes a CPU and memory such as RAM and ROM. The memory stores program code or instructions configured to cause the CPU to perform processes. Memory, i.e., computer-readable media, includes any readable media that can be accessed by a general-purpose or dedicated computer.

[0028] <Processing by the control unit> Next, the processing performed by the control unit 25 will be described. The control unit 25 prints an image onto the medium 99 by controlling the printing unit 12 and the transport unit 19.

[0029] As shown in Figure 3, the control unit 25 prints the job image A1 onto the medium 99 using the printing unit 12. That is, the printing unit 12 prints the job image A1 onto the medium 99. The job image A1 is an image based on a print job. The job image A1 is an image included in a print job. For example, if a print job includes multiple pages, one job image A1 shown in Figure 3 corresponds to one page of the job image A1. A print job includes a command to print one or more job images A1. The control unit 25 prints the job image A1 based on a print job, for example, by receiving a print job from an external source via a network. When the control unit 25 receives a print job, it prints the job image A1 by intermittently transporting the medium 99 using the transport unit 19 and moving the printing unit 12 back and forth along the scanning direction X1. Note that the job image A1 only needs to be an area where it is permissible to form a job image A1. For example, the job image A1 may consist of multiple objects that are far apart from each other. In such cases, the spaces between objects are also permitted to form the job image A1 and are included in the job image A1.

[0030] The control unit 25 prints the adjustment image B1 onto the medium 99 using the printing unit 12. That is, the printing unit 12 prints the adjustment image B1 onto the medium 99. The adjustment image B1 is an image for adjusting the liquid discharge timing by the printing unit 12. More specifically, the adjustment image B1 is an image for adjusting the first discharge timing and the second discharge timing. In one example, the adjustment image B1 is an image for adjusting the second discharge timing relative to the first discharge timing. The adjustment image B1 may also be an image for adjusting the first discharge timing relative to the second discharge timing. The first discharge timing and the second discharge timing are different timings from each other. Based on the adjustment image B1, the control unit 25 adjusts the second discharge timing relative to the first discharge timing. The control unit 25 may also adjust the first discharge timing relative to the second discharge timing based on the adjustment image B1.

[0031] The control unit 25 may print so that the liquid dispensed at the first dispensing timing and the liquid dispensed at the second dispensing timing overlap. That is, the control unit 25 may print so that the landing position of the liquid dispensed at the first dispensing timing overlaps with the landing position of the liquid dispensed at the second dispensing timing. More specifically, in the scanning direction X1, the control unit 25 may print so that the landing position of the liquid dispensed at the first dispensing timing overlaps with the landing position of the liquid dispensed at the second dispensing timing. In this case, the liquid dispensed at the first dispensing timing and the liquid dispensed at the second dispensing timing are positioned in a line when viewed from the transport direction Y1.

[0032] The control unit 25 may perform bidirectional printing. In bidirectional printing, the control unit 25 prints an image by ejecting liquid from the printing unit 12 in both the forward and return directions. Bidirectional printing is so-called Bi-D printing. In bidirectional printing, the first ejection timing is the ejection timing when moving in the forward direction, and the second ejection timing is the ejection timing when moving in the return direction. In other words, in bidirectional printing, the first ejection timing and the second ejection timing are timings in which the carriage 17 moves in different directions. In bidirectional printing, the liquid ejected in the forward direction and the liquid ejected in the return direction may be printed in an overlapping manner. In bidirectional printing, the landing positions of the liquid ejected from the same nozzle row 16 may be aligned during printing.

[0033] The control unit 25 may perform unidirectional printing. In unidirectional printing, the control unit 25 prints an image by ejecting liquid from the printing unit 12 in either the forward or return path. Unidirectional printing is so-called Uni-D printing. In unidirectional printing, for example, the first ejection timing is the ejection timing during the forward movement, and the second ejection timing is the ejection timing during the next forward movement. In other words, in unidirectional printing, the first ejection timing and the second ejection timing are timings for different paths, although the carriage 17 moves in the same direction. In unidirectional printing, the liquid ejected in the forward path may be printed so as to overlap the liquid ejected in the next forward path. In unidirectional printing, the landing positions of the liquid ejected from different nozzle rows 16 may be aligned.

[0034] The ejection timing may gradually shift during printing. For example, when printing multiple job images A1 consecutively, the ejection timing may gradually shift during printing. Therefore, the control unit 25 prints adjustment image B1 while the print job is running. The control unit 25 prints adjustment image B1 in conjunction with printing job image A1. The control unit 25 prints adjustment image B1 in parallel with job image A1.

[0035] Adjustment image B1 contains one or more adjustment patterns P1. In one example, adjustment image B1 contains multiple adjustment patterns P1. Adjustment image B1 contains, for example, five adjustment patterns P1. In adjustment image B1, multiple adjustment patterns P1 are arranged in one direction. In adjustment image B1, multiple adjustment patterns P1 are arranged in the scanning direction X1.

[0036] The adjustment pattern P1 is printed by the liquid dispensed at the first dispensing timing and the liquid dispensed at the second dispensing timing. The control unit 25 causes the printing unit 12 to dispense liquid at the first dispensing timing and the liquid at the second dispensing timing to print the adjustment pattern P1. In other words, the printing unit 12 prints the adjustment pattern P1 by dispensing liquid at the first dispensing timing and the liquid at the second dispensing timing. The adjustment pattern P1 is a test pattern for checking the degree of overlap between the liquid dispensed at the first dispensing timing and the liquid dispensed at the second dispensing timing.

[0037] As shown in Figure 4, the adjustment pattern P1 includes one or more first lines L1 and one or more second lines L2. The first line L1 is a line formed by the liquid discharged at the first discharge timing. The second line L2 is a line formed by the liquid discharged at the second discharge timing. The first line L1 and the second line L2 are rows of dots formed by the liquid discharged from the nozzle row 16. When the first line L1 and the second line L2 are in a single row in the adjustment pattern P1, the impact position of the liquid discharged at the first discharge timing coincides with the impact position of the liquid discharged at the second discharge timing. In other words, in this case, the discharge timing is appropriate. Note that Figure 4 shows an example where the first line L1 and the second line L2 are not in a single row.

[0038] The first line L1 and the second line L2 are printed to form an overlapping portion LP. The overlapping portion LP is the part of the adjustment pattern P1 where the first line L1 and the second line L2 overlap when viewed from the scanning direction X1. The first line L1 and the second line L2 are printed so that part or all of them overlap in the transport direction Y1. The ejection timing is adjusted based on the misalignment between the first line L1 and the second line L2 in the overlapping portion LP.

[0039] As shown in Figure 5, adjustment image B1 includes a reference adjustment pattern P2. The reference adjustment pattern P2 is the adjustment pattern P1 printed by the liquid being dispensed at the currently set dispensing timing. In one example, the reference adjustment pattern P2 is the adjustment pattern P1 printed by the liquid being dispensed at the currently set second dispensing timing.

[0040] Adjustment image B1 may include multiple adjustment patterns P1. Adjustment image B1 may include adjustment patterns P1 in addition to the reference adjustment pattern P2. Multiple adjustment patterns P1 are patterns printed at different ejection timings. In one example, multiple adjustment patterns P1 are patterns printed at different second ejection timings. Multiple adjustment patterns P1 may also be patterns printed at different first ejection timings.

[0041] Adjustment image B1 may include one or more positive adjustment patterns P3. A positive adjustment pattern P3 is an adjustment pattern P1 printed by dispensing liquid at a dispensing timing that is positively shifted from the currently set dispensing timing. That is, a positive adjustment pattern P3 is an adjustment pattern P1 in which the dispensing timing is positively shifted from the reference adjustment pattern P2. In one example, a positive adjustment pattern P3 is an adjustment pattern P1 in which the second dispensing timing is positively shifted from the reference adjustment pattern P2.

[0042] One or more adjustment patterns P1 may include one or more negative adjustment patterns P4. A negative adjustment pattern P4 is an adjustment pattern P1 printed by dispensing liquid at a dispensing timing that is shifted in the negative direction from the currently set dispensing timing. That is, a negative adjustment pattern P4 is an adjustment pattern P1 in which the dispensing timing is shifted in the negative direction from the reference adjustment pattern P2. In one example, a negative adjustment pattern P4 is an adjustment pattern P1 in which the second dispensing timing is shifted in the negative direction from the reference adjustment pattern P2.

[0043] Multiple positive adjustment patterns P3 are printed such that the amount of deviation in ejection timing relative to the reference adjustment pattern P2 is different for each. Multiple positive adjustment patterns P3 are printed, for example, by shifting the ejection timing in the positive direction by a predetermined amount relative to the reference adjustment pattern P2. Multiple positive adjustment patterns P3 are printed by shifting the second ejection timing in the positive direction by a predetermined amount relative to the reference adjustment pattern P2.

[0044] Multiple negative adjustment patterns P4 are printed such that the amount of deviation in the ejection timing relative to the reference adjustment pattern P2 is different for each. Multiple negative adjustment patterns P4 are printed, for example, by shifting the ejection timing in the negative direction by a predetermined amount relative to the reference adjustment pattern P2. Multiple negative adjustment patterns P4 are printed by shifting the second ejection timing in the negative direction by a predetermined amount relative to the reference adjustment pattern P2.

[0045] The control unit 25 is configured to adjust the discharge timing based on the detection result of the adjustment image B1 by the detection unit 22. The control unit 25 adjusts the discharge timing by detecting the adjustment image B1 with the detection unit 22. Specifically, the control unit 25 adjusts the discharge timing by detecting one or more adjustment patterns P1 with the detection unit 22. In one example, the control unit 25 adjusts the second discharge timing relative to the first discharge timing based on the detection result of the adjustment image B1.

[0046] The control unit 25 detects the amount of misalignment between the first line L1 and the second line L2 in the adjustment pattern P1 using the detection unit 22. The control unit 25 detects the amount of misalignment between the first line L1 and the second line L2 by detecting the concentration of the overlapping portion LP using the detection unit 22. When the amount of misalignment between the first line L1 and the second line L2 is large, the liquid is uniformly distributed in the overlapping portion LP. When the amount of misalignment between the first line L1 and the second line L2 is small, the liquid is unevenly distributed in the overlapping portion LP. Therefore, when the amount of misalignment between the first line L1 and the second line L2 is large, a high concentration of the overlapping portion LP is detected.

[0047] The control unit 25 may adjust the discharge timing when the amount of deviation between the first line L1 and the second line L2 in the reference adjustment pattern P2 is large. For example, the control unit 25 determines that the amount of deviation between the first line L1 and the second line L2 is large when the concentration of the overlapping portion LP is greater than a threshold. The control unit 25 may adjust the discharge timing based on the concentration of the overlapping portion LP when the amount of deviation between the first line L1 and the second line L2 in the reference adjustment pattern P2 is large.

[0048] The control unit 25 may adjust the discharge timing based on the detection results of multiple adjustment patterns P1. The control unit 25 may adjust the discharge timing based on the detection results of one or more positive adjustment patterns P3 and one or more negative adjustment patterns P4. The control unit 25 may change the discharge timing to the adjustment pattern P1 among the multiple adjustment patterns P1 in which the concentration of the overlapping portion LP is smallest. That is, the control unit 25 may change the discharge timing to the adjustment pattern P1 among the multiple adjustment patterns P1 in which the amount of deviation between the first line L1 and the second line L2 is smallest. The control unit 25 may change the discharge timing to the adjustment pattern P1 among the multiple adjustment patterns P1 in which the concentration of the overlapping portion LP is below a threshold.

[0049] The control unit 25 may confirm with the user whether to adjust the discharge timing based on the detection result of the adjustment image B1 by the detection unit 22. The control unit 25 may, for example, prompt the user to adjust the discharge timing based on the detection result of the adjustment image B1. If the amount of misalignment between the first line L1 and the second line L2 is large, the control unit 25 may notify the user via the notification unit 23 that the amount of misalignment between the first line L1 and the second line L2 is large. The control unit 25 may automatically adjust the discharge timing based on the detection result of the adjustment image B1.

[0050] As shown in Figure 3, the control unit 25 prints the adjustment image B1 in the margin portion of the medium 99 when printing the job image A1. More specifically, the control unit 25 prints the adjustment image B1 in the margin portion of the medium 99 adjacent to the job image A1 in the scanning direction X1.

[0051] The control unit 25 prints the adjustment image B1 so that it is aligned with the job image A1. More specifically, the control unit 25 prints the adjustment image B1 so that it is aligned with the job image A1 in the scanning direction X1. In other words, the control unit 25 prints both the job image A1 and the adjustment image B1 so that they are aligned in the scanning direction X1. The control unit 25 prints the job image A1 and the adjustment image B1 in parallel by moving the printing unit 12 back and forth along the scanning direction X1. By aligning the adjustment image B1 with the job image A1 in the scanning direction X1, media consumption is reduced compared to when the adjustment image B1 is aligned with the job image A1 in the transport direction Y1.

[0052] The control unit 25 prints the adjustment image B1 so that it is aligned with the upstream portion of the job image A1 in the scanning direction X1. More specifically, the control unit 25 prints the adjustment image B1 such that the distance to the upstream end A3 of the job image A1 is smaller than the distance to the downstream end A2 of the job image A1 in the transport direction Y1. The downstream end A2 is the end of the job image A1 located downstream in the transport direction Y1. The upstream end A3 is the end of the job image A1 located upstream in the transport direction Y1. The downstream end A2 consists of, for example, the first line of the job image A1 to be printed. The upstream end A3 consists of, for example, the last line of the job image A1 to be printed. The control unit 25 may print the final line of the job image A1 and the adjustment image B1 at the same time.

[0053] The control unit 25 may print the check image C1. That is, the printing unit 12 may print the check image C1. The check image C1 is an image for checking the discharge status of multiple nozzles 14. The check image C1 is an image for checking a state in which liquid is not discharged normally from the nozzles 14, so-called nozzle failure. The check image C1 is formed, for example, by discharging liquid from all nozzles 14 simultaneously. The user checks whether nozzle failure has occurred by checking the check image C1.

[0054] The control unit 25 may print the check image C1 in the margin portion of the medium 99 when printing the job image A1. For example, the control unit 25 may print the check image C1 in the margin portion of the medium 99 adjacent to the job image A1 in the scanning direction X1.

[0055] The control unit 25 may print the check image C1 so that it is aligned with the job image A1. In one example, the control unit 25 prints the check image C1 so that it is aligned with the job image A1 in the scanning direction X1. The control unit 25 prints both the job image A1 and the check image C1 so that they are aligned in the scanning direction X1. The control unit 25 prints the job image A1 and the check image C1 in parallel by moving the printing unit 12 back and forth along the scanning direction X1.

[0056] The control unit 25 prints the check image C1 so that it is aligned with the adjustment image B1 in the transport direction Y1. More specifically, the control unit 25 prints the check image C1 so that it is located downstream of the adjustment image B1 in the transport direction Y1. In other words, the control unit 25 prints the check image C1 before the adjustment image B1 while the job image A1 is being printed. The control unit 25 prints the check image C1 so that the distance between the check image C1 and the downstream end A2 is smaller than the distance between the adjustment image B1 and the downstream end A2 in the transport direction Y1.

[0057] The control unit 25 may print multiple check images C1 while printing the job image A1. For example, the control unit 25 may print the check images C1 together with the job image A1 each time the printing unit 12 moves in the scanning direction X1. That is, the control unit 25 may print one line of job image A1 and the check images C1 at the same time. In this case, the multiple check images C1 will be arranged in the transport direction Y1.

[0058] The control unit 25 detects the adjustment image B1 using the detection unit 22 after the printing of the adjustment image B1 is complete. More specifically, the control unit 25 detects the adjustment image B1 using the detection unit 22 after the printing of the job image A1 and the adjustment image B1 is complete. Therefore, after the printing of the job image A1 and the adjustment image B1 is complete, the control unit 25 adjusts the position of the medium 99 and the detection unit 22 in the transport direction Y1 so that the detection unit 22 passes over the adjustment image B1. Since the adjustment image B1 is positioned so as to be aligned with the upstream portion of the job image A1 in the scanning direction X1, the distance between the printing unit 12 and the adjustment image B1 is short when the printing of the job image A1 and the adjustment image B1 is complete. In other words, the distance between the detection unit 22 and the adjustment image B1 is short. As a result, the time required for the detection unit 22 to detect the adjustment image B1 is reduced.

[0059] After the job image A1 and adjustment image B1 are printed, the control unit 25 aligns the detection unit 22 with the adjustment image B1 by transporting the medium 99 in reverse relative to the printing unit 12 using the transport unit 19. After the job image A1 and adjustment image B1 are printed, the control unit 25 aligns the detection unit 22 with the adjustment image B1 by reversing the rotation of the upper transport roller 20. At this time, since the adjustment image B1 is positioned so as to be aligned with the upstream portion of the job image A1 in the scanning direction X1, the amount of transport during reverse transport is small. Therefore, the time required for the detection unit 22 to detect the adjustment image B1 is reduced. The printing apparatus 10 may also have a layout that allows the detection unit 22 to pass directly above the adjustment image B1 without transporting the medium 99 in reverse when the job image A1 and adjustment image B1 are printed. After printing the job image A1 and the adjustment image B1, the printing device 10 may align the detection unit 22 with the adjustment image B1 by transporting the medium 99 relative to the printing unit 12 using the transport unit 19.

[0060] If the medium 99 is transported in reverse, there is a risk that the job image A1 may reach the upper transport roller 20. In this case, there is a risk that the job image A1 may be transferred to the upper transport roller 20. To address this, the upper transport roller 20 is positioned upstream of the printing unit 12 in the transport direction Y1 so as not to come into contact with the job image A1 when the medium 99 is transported in reverse. For example, the upper transport roller 20 is positioned upstream of the printing unit 12 such that, when the printing of the job image A1 and adjustment image B1 is completed, the distance between the detection unit 22 and the adjustment image B1 is smaller than the distance between the upstream end A3 and the upper transport roller 20 in the transport direction Y1. In other words, when the printing of the job image A1 and adjustment image B1 is completed, the control unit 25 prints the adjustment image B1 using the printing unit 12 such that, in the transport direction Y1, the distance between the detection unit 22 and the adjustment image B1 is smaller than the distance between the upstream end A3 and the upper transport roller 20. This reduces the risk of the job image A1 being transferred to the upper transport roller 20.

[0061] As shown in Figure 6, the control unit 25 may print the adjustment image D1. The adjustment image D1 is an image containing multiple adjustment patterns P1. The adjustment image D1 has a larger number of adjustment patterns P1 compared to the adjustment image B1. The adjustment image D1 contains a greater number of adjustment patterns P1 than the adjustment image B1 contains. Specifically, the adjustment image D1 has a larger number of positive adjustment patterns P3 and a larger number of negative adjustment patterns P4 compared to the adjustment image B1. The adjustment image D1 may also contain adjustment patterns P1 with larger displacement amounts for the first line L1 and the second line L2 compared to the adjustment image B1. The adjustment image D1 may also contain adjustment patterns P1 with smaller displacement amounts for the first line L1 and the second line L2 compared to the adjustment image B1. The adjustment image D1 may also include a reference adjustment pattern P2.

[0062] The control unit 25 may cause the printing unit 12 to print the adjustment image D1 based on the detection result of the adjustment image B1 by the detection unit 22. For example, the control unit 25 may cause the printing unit 12 to print the adjustment image D1 if it determines that adjustment of the ejection timing is necessary based on the detection result of the adjustment image B1. The control unit 25 may cause the printing unit 12 to print the adjustment image D1 if the amount of deviation between the first line L1 and the second line L2 in the reference adjustment pattern P2 included in the adjustment image B1 is large. The control unit 25 may cause the printing unit 12 to print the adjustment image D1 if the adjustment image B1 does not include an adjustment pattern P1 in which the amount of deviation between the first line L1 and the second line L2 is below a threshold.

[0063] The control unit 25 may print the adjustment image D1 so as to be aligned with the job image A1 in the transport direction Y1. In one example, the control unit 25 prints the adjustment image D1 so as to be aligned with the job image A1 and adjustment image B1 in the transport direction Y1. The control unit 25 prints the adjustment image D1 after printing the job image A1 and adjustment image B1. The control unit 25 prints the adjustment image D1 before printing the next job image A1. The control unit 25 prints the adjustment image D1 between multiple job images A1.

[0064] The control unit 25 adjusts the ejection timing by detecting the adjustment image D1 with the detection unit 22. Similar to when adjusting based on the adjustment image B1, the control unit 25 changes the ejection timing to the adjustment pattern P1 in which the amount of deviation between the first line L1 and the second line L2 is smallest among the multiple adjustment patterns P1 included in the adjustment image D1. The control unit 25 changes the ejection timing to the adjustment pattern P1 in which the amount of deviation between the first line L1 and the second line L2 is less than or equal to a threshold among the multiple adjustment patterns P1 included in the adjustment image D1. Compared with the detection result of the adjustment image B1, the detection result of the adjustment image D1 shows the amount of deviation between the first line L1 and the second line L2 in more detail. Therefore, the control unit 25 can finely adjust the ejection timing based on the detection result of the adjustment image D1.

[0065] The control unit 25 may print the adjustment image D1 before printing the job image A1. More specifically, when the control unit 25 receives a print job, it may print the adjustment image D1 before starting to print the job image A1. The control unit 25 can properly print the first job image A1 by adjusting the ejection timing based on the adjustment image D1.

[0066] <Printing process> Next, the printing process will be described. The printing process is the process of printing an image onto the medium 99. The printing process is the process of printing job image A1. The printing process includes the process of printing adjustment image B1. The printing process is performed by the control unit 25. The printing process is started when the control unit 25 receives a print job.

[0067] As shown in Figure 7, in step S11, the control unit 25 prints an image based on the print job. At this time, the control unit 25 prints an image on the medium 99 by alternately repeating the transport of the medium 99 by the transport unit 19 and the discharge of liquid by the printing unit 12. The control unit 25 prints the job image A1. The control unit 25 prints the job image A1 and also prints the adjustment image B1. The control unit 25 prints the adjustment image B1 so that it is aligned with the job image A1 in the scanning direction X1, and the distance to the upstream end A3 is smaller than the distance to the downstream end A2. The control unit 25 may also print the check image C1 along with the job image A1.

[0068] In step S12, the control unit 25 reverses the transport unit 19 to transport the medium 99. The control unit 25 transports the medium 99 in the opposite direction to the transport direction Y1, for example, by reversing the rotation of the upper transport roller 20. At this time, the control unit 25 reverses the transport unit 19 to transport the medium 99 so that the detection unit 22 can detect the overlapping portion LP. The control unit 25 reverses the transport unit 19 to transport the medium 99 so that the detection unit 22 and the adjustment image B1 overlap in the transport direction Y1.

[0069] In step S13, the control unit 25 detects the adjustment image B1 by moving the printing unit 12 in the scanning direction X1. The control unit 25 detects the density of the overlapping portion LP of the adjustment pattern P1 contained in the adjustment image B1.

[0070] In step S14, the control unit 25 determines whether the liquid's landing position is off based on the detection result of the adjustment image B1. That is, the control unit 25 determines whether adjustment of the ejection timing is necessary. If adjustment of the ejection timing is not necessary, the control unit 25 terminates the printing process. If adjustment of the ejection timing is necessary, the control unit 25 proceeds to step S15.

[0071] In step S15, the control unit 25 determines whether automatic adjustment of the discharge timing is set. That is, the control unit 25 confirms whether automatic adjustment of the discharge timing is permitted by the user. If automatic adjustment of the discharge timing is permitted, the control unit 25 proceeds to step S16. If automatic adjustment of the discharge timing is not permitted, the control unit 25 proceeds to step S17.

[0072] In step S16, the control unit 25 adjusts the ejection timing. The control unit 25 adjusts the ejection timing based on the detection result of the adjustment image B1. For example, the control unit 25 changes the ejection timing to the adjustment pattern P1 in which the amount of misalignment between the first line L1 and the second line L2 is smallest. The control unit 25 may also change the ejection timing based on the amount of misalignment between the first line L1 and the second line L2. After adjusting the ejection timing, the control unit 25 terminates the printing process.

[0073] In step S17, the control unit 25 notifies the user that the dispensing timing is off. At this time, the control unit 25 notifies the user that the dispensing timing needs to be adjusted. For example, the control unit 25 displays a screen on the notification unit 23 prompting the user to adjust the dispensing timing. The control unit 25 may also display a screen on the notification unit 23 accepting the request for dispensing timing adjustment.

[0074] In step S18, the control unit 25 confirms with the user whether or not to adjust the ejection timing. At this time, the control unit 25 may display a screen on the notification unit 23 confirming whether or not to adjust the ejection timing. The control unit 25 waits for instructions from the user. When the control unit 25 receives an instruction to adjust the ejection timing, it proceeds to step S19. When the control unit 25 receives an instruction not to adjust the ejection timing, it terminates the printing process.

[0075] In step S19, the control unit 25 determines whether the ejection timing can be adjusted based on the detection result of the adjustment image B1. That is, the control unit 25 determines whether the ejection timing can be adjusted based on the detection result in step S13. For example, the control unit 25 checks whether the adjustment image B1 contains an adjustment pattern P1 in which the amount of displacement between the first line L1 and the second line L2 is small. If the control unit 25 determines that the ejection timing can be adjusted based on the detection result of the adjustment image B1, it proceeds to step S16. In this case, the control unit 25 adjusts the ejection timing based on the detection result in step S13. If the control unit 25 determines that the ejection timing cannot be adjusted based on the detection result of the adjustment image B1, it proceeds to step S20.

[0076] In step S20, the control unit 25 prints the adjustment image D1. The control unit 25 prints the adjustment image D1 at a position aligned with the job image A1 in the transport direction Y1. That is, after the transport unit 19 transports the medium 99, the control unit 25 prints the adjustment image D1 using the printing unit 12.

[0077] In step S21, the control unit 25 detects the adjustment image D1. Specifically, the control unit 25 moves the medium 99 to a position where the adjustment image D1 can be detected by the detection unit 22, and then moves the printing unit 12 in the scanning direction X1. For example, after printing the adjustment image D1 is complete, the control unit 25 reverses the transport of the medium 99 to align the position of the detection unit 22 with the adjustment image D1. The control unit 25 detects the adjustment image D1 by the detection unit 22 by moving the printing unit 12 in the scanning direction X1. Once the control unit 25 obtains the detection result of the adjustment image D1, it proceeds to step S16. In this case, the control unit 25 adjusts the ejection timing based on the detection result of the adjustment image D1.

[0078] <Effects and Effects of the Examples> Next, the operation and effects of the examples will be described. (1) The control unit 25 prints the adjustment image B1 using the printing unit 12 such that it is aligned with the job image A1 in the scanning direction X1, and the distance to the upstream end A3 is less than the distance to the downstream end A2 in the transport direction Y1. With the above configuration, since the job image A1 and the adjustment image B1 are aligned in the scanning direction X1, the amount of media consumed is less compared to when the job image A1 and the adjustment image B1 are aligned in the transport direction Y1. Since the adjustment image B1 is located near the upstream end A3 in the transport direction Y1, the position of the adjustment image B1 and the printing unit 12 becomes close when the printing of the job image A1 and the adjustment image B1 is completed. Therefore, the time required to detect the adjustment image B1 is less compared to when the positions of the adjustment image B1 and the printing unit 12 are far apart when the printing of the job image A1 and the adjustment image B1 is completed. Accordingly, the risk of increased media consumption and the time required to detect the adjustment image B1 is reduced.

[0079] (2) After the job image A1 and adjustment image B1 have been printed, the control unit 25 uses the transport unit 19 to transport the medium 99 in the reverse direction relative to the printing unit 12, thereby aligning the position of the detection unit 22 with the adjustment image B1. With the above configuration, the detection unit 22 can quickly detect the adjustment image B1.

[0080] (3) The upper transport roller 20 is positioned upstream of the printing unit 12 in the transport direction Y1 so as not to come into contact with the job image A1 when the medium 99 is transported in the reverse direction. With the above configuration, the risk of the job image A1 being transferred to the upper transport roller 20 is reduced.

[0081] (4) The control unit 25 prints the check image C1 using the printing unit 12 such that it is aligned with the job image A1 in the scanning direction X1, and the distance between the check image C1 and the downstream end A2 is smaller than the distance between the adjustment image B1 and the downstream end A2 in the transport direction Y1. With the above configuration, the risk of increased media consumption due to the printing of the check image C1 is reduced.

[0082] (5) The printing unit 12 prints the adjustment pattern P1 by ejecting liquid at the first ejection timing and at the second ejection timing. The first ejection timing and the second ejection timing are either when the movement direction of the carriage 17 is different from each other, or when they are on different passes. With the above configuration, the first ejection timing and the second ejection timing can be adjusted based on the adjustment pattern P1.

[0083] (6) The control unit 25 confirms with the user whether or not to adjust the liquid discharge timing by the printing unit 12 based on the detection result of the adjustment image B1 by the detection unit 22. With the above configuration, the risk of the discharge timing being changed automatically is reduced.

[0084] (7) The control unit 25 prints the adjustment image D1 using the printing unit 12 based on the detection result of the adjustment image B1 by the detection unit 22. With the above configuration, the ejection timing can be finely adjusted using the adjustment image D1.

[0085] <Technical philosophy> The technical concepts and their effects, as understood from the above-described embodiments and modifications, are explained below.

[0086] (A) The printing apparatus is a printing unit that prints a job image and an adjustment image onto a medium, and comprises a head for ejecting liquid onto the medium, and a carriage on which the head is mounted and which moves in the scanning direction relative to the medium; a detection unit mounted on the carriage for detecting the adjustment image which includes one or more adjustment patterns; a transport unit that transports the medium relative to the printing unit in a transport direction different from the scanning direction; and a control unit that adjusts the liquid ejection timing based on the detection result of the adjustment image by the detection unit, wherein the control unit prints the adjustment image using the printing unit such that it is aligned with the job image in the scanning direction, and the distance to the upstream end of the job image is smaller than the distance to the downstream end of the job image in the transport direction. With the above configuration, since the job image and the adjustment image are aligned in the scanning direction, the amount of medium consumed is less compared to when the job image and the adjustment image are aligned in the transport direction. Since the adjustment image is located near the upstream end of the job image in the transport direction, the position of the adjustment image and the printing unit are close when the printing of the job image and the adjustment image is completed. Therefore, compared to cases where the adjustment image and the printing area are far apart when printing of the job image and adjustment image is complete, less time is required to detect the adjustment image. Consequently, the risk of increased media consumption and the time required to detect the adjustment image is reduced.

[0087] (B) In the above printing apparatus, the control unit may, after the printing of the job image and the adjustment image is completed, align the detection unit with the adjustment image by transporting the medium in the reverse direction relative to the printing unit using the transport unit. With the above configuration, the detection unit can quickly detect the adjustment image.

[0088] (C) In the above printing apparatus, the transport unit has an upper transport roller for transporting the medium, and the upper transport roller may be located upstream of the printing unit in the transport direction so as not to come into contact with the job image when the medium is transported in the reverse direction. With the above configuration, the risk of the job image being transferred to the upper transport roller is reduced.

[0089] (D) In ​​the above-described printing apparatus, the head has a nozzle surface provided with a plurality of nozzles from which liquid is discharged, and the control unit may print a check image for confirming the discharge state of the plurality of nozzles, aligned with the job image in the scanning direction, and such that the distance between the check image and the downstream end is smaller than the distance between the adjustment image and the downstream end in the transport direction, using the printing unit. With the above configuration, the risk of increased media consumption due to the printing of the check image is reduced.

[0090] (E) In the above printing apparatus, the printing unit prints the adjustment pattern by discharging liquid at a first discharging timing and discharging liquid at a second discharging timing different from the first discharging timing, wherein the first discharging timing and the second discharging timing may be at different directions of movement of the carriage or at different paths. With the above configuration, the first discharging timing and the second discharging timing can be adjusted based on the adjustment pattern.

[0091] (F) In the above-described printing apparatus, the control unit may confirm with the user whether or not to adjust the liquid discharge timing by the printing unit based on the detection result of the adjustment image by the detection unit. With the above configuration, the risk of the discharge timing being changed automatically is reduced.

[0092] (G) In the above printing apparatus, the control unit may, based on the detection result of the adjustment image by the detection unit, print a final adjustment image containing more adjustment patterns than the number of adjustment patterns contained in the adjustment image using the printing unit. With the above configuration, the ejection timing can be finely adjusted using the final adjustment image. [Explanation of Symbols]

[0093] 10...Printing device, 11...Housing, 12...Printing section, 13...Head, 14...Nozzle, 15...Nozzle surface, 16...Nozzle row, 17...Carriage, 18...Support section, 19...Transport section, 20...Upper transport roller, 21...Lower transport roller, 22...Detection section, 23...Notification section, 24...Operation section, 25...Control section, 99...Media, A1...Job image, A2...Downstream end, A3...Upstream end, B1...Adjustment image, C1...Check image, D1...Main adjustment image, L1...First line, L2...Second line, LP...Overlapped section, P1...Adjustment pattern, P2...Reference adjustment pattern, P3...Positive adjustment pattern, P4...Negative adjustment pattern, X1...Scanning direction, Y1...Transport direction.

Claims

1. A printing unit for printing a job image and an adjustment image onto a medium, the printing unit having a head for dispensing liquid onto the medium, and a carriage on which the head is mounted and which moves in the scanning direction relative to the medium, A detection unit mounted on the carriage detects the adjustment image which includes one or more adjustment patterns, A transport unit that transports the medium relative to the printing unit in a transport direction different from the scanning direction, The system includes a control unit that adjusts the liquid discharge timing based on the detection result of the adjustment image by the detection unit, The printing apparatus is characterized in that the control unit prints the adjustment image using the printing unit such that the adjustment image is aligned with the job image in the scanning direction and the distance to the upstream end of the job image is less than the distance to the downstream end of the job image in the transport direction.

2. The printing apparatus according to claim 1, characterized in that the control unit, after the completion of printing the job image and the adjustment image, aligns the positions of the detection unit and the adjustment image by transporting the medium in the reverse direction relative to the printing unit using the transport unit.

3. The transport unit has transport rollers for transporting the medium, The printing apparatus according to claim 2, characterized in that the transport roller is located upstream of the printing section in the transport direction so as not to come into contact with the job image when the medium is transported in the reverse direction.

4. The head has a nozzle surface provided with a plurality of nozzles from which liquid is discharged, The printing apparatus according to claim 1, characterized in that the control unit prints a check image for confirming the discharge state of the plurality of nozzles, aligned with the job image in the scanning direction, and such that the distance between the check image and the downstream end is smaller than the distance between the adjustment image and the downstream end in the transport direction.

5. The printing unit prints the adjustment pattern by discharging liquid at a first discharging timing and discharging liquid at a second discharging timing different from the first discharging timing. The printing apparatus according to claim 1, characterized in that the first ejection timing and the second ejection timing are the timings of the carriage's movement in different directions or the timings of different passes.

6. The printing apparatus according to claim 1, characterized in that the control unit confirms with the user whether or not to adjust the liquid discharge timing by the printing unit based on the detection result of the adjustment image by the detection unit.

7. The printing apparatus according to claim 1, characterized in that the control unit prints the adjusted image, which includes a number of adjustment patterns greater than the number of adjustment patterns included in the adjusted image, using the printing unit, based on the detection result of the adjusted image by the detection unit.

Images