Printing system and method for controlling printing device

Abstract

The present invention reduces positional deviations of a plurality of ink layers when performing pullback printing on a medium.　When printing an image in which an ink layer L1 formed by a head 35 is overlapped on an ink layer L2 formed by a head 36, a print data creation unit 13 of an information processing device 10 forms the ink layer L2 by means of the head 36 on print data PDb for forming the ink layer L2 by means of the head 36, then returns the ink layer L2 to the position of the head 35 on the upstream side in a conveyance direction by means of a delivery mechanism 41; and adds pullback printing control data CDa for detecting a mark mk by means of a sensor. A correction unit 14 corrects image data according to the position information about the mark mk detected by a sensor 38. The print data creation unit 13 creates print data PDa for forming the ink layer L1 by means of the head 35 by using the image data corrected by the correction unit 14.

Description

Printing system and printing device control method

[0001] The present invention relates to a printing system and a method for controlling a printing device.

[0002] A printing device may print an image on a medium in which multiple ink layers are superimposed (see, for example, Patent Document 1). When the printing device has multiple heads that are positioned at different positions in the transport direction of the medium, the printing device ejects ink from one head to form an ink layer, then transports the formed ink layer to the position of another head, and ejects ink from the other head to superimpose the ink layers.

[0003] Japanese Patent Application Laid-Open No. 2018-111257

[0004] Depending on the specifications of the image to be printed, a printing device may overlay an ink layer formed by a head located upstream in the transport direction on an ink layer formed by a head located downstream in the transport direction. In this case, the printing device performs an operation to pull the media back from the downstream side to the upstream side in the transport direction. In a printing device, the media is transported in a specified orientation, but the pullback may cause a slight tilt. If ink layers are overlaid on tilted media, the multiple ink layers may not overlap properly due to misalignment, which may affect print quality.

[0005] To address this issue, there is a need to reduce the misalignment of the ink layer when performing media pull-back printing in a printing device, thereby reducing the impact on print quality.

[0006] One aspect of the present invention is as follows: (1) A printing system comprising: a printing device capable of printing an image in which multiple ink layers are superimposed on a medium; and a control device that controls the operation of the printing device, wherein the printing device comprises: a transport mechanism that transports the medium; a first head having nozzles that eject ink onto the medium; a second head having nozzles that eject ink onto the medium and positioned downstream in a transport direction of the medium relative to the first head; and a sensor that detects marks printed on the medium, and the control device comprises: a print data creation unit that creates print data for controlling the operation of the printing device based on data of the image; and a correction unit that corrects data of the image based on position information of the mark detected by the sensor, and when printing an image in which an ink layer formed by the first head is superimposed on an ink layer formed by the second head, the print data creation unit adds control data to second print data for forming the ink layer with the second head, after the ink layer is formed by the second head, for returning the ink layer by the transport mechanism to a position of the first head upstream in the transport direction and for detecting the mark with the sensor, First print data for forming the ink layer with the first head is created using the image data corrected by the correction unit.

[0007] (2) In the printing system of (1), the print data creation unit determines whether to add the control data to the second print data based on the layering order of the ink layers that make up the image.

[0008] (3) In the printing system of (2), if the stacking order is such that an ink layer is formed by the second head after an ink layer is formed by the first head, the print data creation unit adds the control data to the second print data for forming an ink layer by the second head, and if the stacking order is such that an ink layer is formed by the second head after an ink layer is formed by the first head, the print data creation unit does not add the control data to the second print data for forming an ink layer by the second head.

[0009] (4) In any of the printing systems (1) to (3), if the stacking order of the multiple ink layers constituting the image includes a stacking order in which an ink layer is formed by the second head and then an ink layer is formed by the first head, the print data creation unit adds control data to the print data for forming the first ink layer for printing the mark on the medium by the first head or the second head.

[0010] (5) In any of the printing systems (1) to (4), the printing data includes information specifying the ink ejection position on the medium, and the correction unit corrects the image data by changing the ink ejection position in accordance with the tilt or positional deviation of the mark detected by the sensor.

[0011] (6) In any of the printing systems (1) to (5), the sensor is disposed on a carriage that carries the first head and the second head and is movable in a direction perpendicular to the transport direction, and the printing device detects the mark printed on the media using the sensor while moving the carriage in a direction perpendicular to the transport direction.

[0012] (7) In any of the printing systems (1) to (6), the printing device causes the first head or the second head to print the mark at a position surrounding the first layer of ink formed by the second head.

[0013] (8) In the printing system of any of (1) to (7), the second head is capable of ejecting adhesive ink onto the medium, and the printing device includes a transfer unit that is disposed downstream of the first head or the second head in the transport direction and that presses a foil transfer sheet, having foil formed on a base material, against the medium to transfer the foil to the portion of the medium onto which the adhesive ink has been ejected, and when the image is printed by overlaying an ink layer formed by the first head or the second head on a foil transfer layer formed by transferring the foil to the adhesive ink by the transfer unit, the print data creation unit adds control data to foil transfer data for forming the foil transfer layer, for printing the mark by the first head or the second head and transferring the foil by the transfer unit, and for returning the foil transfer layer to the position of the first head or the second head upstream in the transport direction by the transport mechanism, and for detecting the mark by the sensor, The first print data or the second print data for forming the ink layer with the first head or the second head is created using the image data corrected by the correction unit.

[0014] One aspect of the present invention is (9) a method for controlling a printing device capable of printing an image in which multiple ink layers are superimposed on a medium, the printing device comprising: a transport mechanism for transporting the medium; a first head having nozzles for ejecting ink onto the medium; a second head having nozzles for ejecting ink onto the medium and positioned downstream in the transport direction of the medium relative to the first head; and a sensor for detecting marks printed on the medium, the method including: a print data creation step for creating print data for controlling operation of the printing device based on data of the image; and a correction step for correcting the image data based on positional information of the mark detected by the sensor, wherein when the image is printed in the printing device by superimposing an ink layer formed by the first head on an ink layer formed by the second head, in the print data creation step: The mark is printed by the first head or the second head on second print data for forming the ink layer by the second head, and after forming the ink layer by the second head, the ink layer is returned by the transport mechanism to the position of the first head upstream in the transport direction, and control data is added for detecting the mark by the sensor, and first print data for forming the ink layer by the first head is created using the image data corrected by the unit in the correction step.

[0015] According to the present invention, when performing pull-back printing on a medium, it is possible to reduce degradation of print quality due to misalignment of the ink layer.

[0016] 1 is a schematic diagram showing the configuration of a printing system according to an embodiment. It is a schematic diagram showing the configuration of a head unit. (a) is a diagram showing a printed example of an image in which multiple ink layers are superimposed, and (b) is a cross-sectional view taken along line A-A of (a). It is a diagram explaining a printing method for the image of FIG. 3. (a) is a diagram showing another printed example of an image in which multiple ink layers are superimposed, and (b) is a cross-sectional view taken along line A-A of (a). It is a diagram explaining a printing method for the image of FIG. 5. It is a block diagram showing the functional configuration of an information processing device. It is a diagram showing an example of a job list. It is a diagram explaining the processing flow of a printing system when executing a compositing job that includes pullback printing. (a) is a diagram showing the tilt of ink layers due to pullback of a medium, and (b) is a diagram showing an example of image data correction. It is a diagram showing an example of a printed image in which three or more ink layers are superimposed. It is a flowchart showing the processing flow of an information processing device. It is a schematic diagram showing the configuration of a printing system according to a first modified example. (a) is a diagram showing an example of a printed image using a transfer unit, and (b) is a cross-sectional view taken along line A-A of (a). It is a diagram explaining a printing method for the image of FIG. FIG. 10 is a diagram illustrating the flow of processing in the printing system when a combining job is executed in Modification 1.

[0017] An embodiment of the present invention will now be described. FIG. 1 is a schematic diagram showing the configuration of a printing system 1 according to an embodiment. As shown in FIG. 1, the printing system 1 includes a printing device 2 that prints an image by ejecting ink onto a medium M, and an information processing device 10 (control device) that controls the operation of the printing device 2. In the following description, the direction from the front (left side of FIG. 1 ) to the rear (right side of FIG. 1 ) of the printing device 2 will be referred to as the "X direction." The direction perpendicular to the X direction, which is the left-right direction of the printing device 2 (the direction from the front side to the back side of the paper in FIG. 1 ), will be referred to as the "Y direction." The direction perpendicular to the X direction (the vertical direction) when the printing device 2 is placed on a horizontal surface, and which is perpendicular to the X and Y directions, will be referred to as the "Z direction."

[0018] The printing device 2 according to this embodiment is an inkjet printing device that prints an image by ejecting ink droplets onto a medium M. The medium M is not limited to a specific type, but examples include paper, fabric (woven fabric, nonwoven fabric), and resin sheets such as vinyl chloride and polyester. The image printed on the medium M includes, for example, characters, figures, patterns, colors, and combinations thereof.

[0019] 1, the printing device 2 includes a printing unit 3, a platen 4, and a base 5 that supports the printing unit 3 and the platen 4. The printing device 2 also includes a controller 8 that controls the operation of each part of the printing device 2. The base 5 is placed on the floor, and the printing unit 3 and the platen 4 are supported on the top of the base 5.

[0020] The printing unit 3 includes a housing 31, and a carriage 32 and guide rails 33 housed inside the housing 31. The carriage 32 is equipped with a head unit 34 that ejects ink and a sensor 38 for detecting marks (described below). Although not shown, if ultraviolet-curable ink is used, the carriage 32 may be equipped with an ultraviolet irradiation unit. The guide rails 33 are arranged along the Y direction. The carriage 32 is driven by a drive mechanism (not shown) and is movable in the Y direction along the guide rails 33. As the carriage 32 moves, the head unit 34 and sensor 38 mounted on the carriage 32 also move in the Y direction. The controller 8 can be mounted on the housing 31, for example. The controller 8 can include an operation panel that displays information related to printing to the user and accepts operation inputs from the user.

[0021] The head unit 34 is provided with a gap between it and the upper surface of the platen 4. Although not shown in Figure 1, a plurality of nozzles, which are ink ejection ports, are arranged on the surface of the head unit 34 facing the platen 4.

[0022] 1, the medium M is wrapped around the upper surface of the platen 4 in a direction transverse to the X direction. A feed mechanism 41 that transports the medium M in the X direction is provided on the platen 4 behind the head unit 34. The length direction of the medium M is arranged along the X direction, and the width direction is arranged along the Y direction. Although not shown, when using ink that requires drying, such as thermosetting ink, solvent ink, or resin ink, the platen 4 may have a built-in heater for heating the ink ejected onto the medium M.

[0023] The feed mechanism 41 has a pair of rollers that grip the media M in the vertical direction. The feed mechanism 41 has a drive mechanism (not shown) that rotates at least one of the rollers. The media M gripped by the pair of rollers is fed in a direction (front or rear in the X direction) that corresponds to the rotation direction of the rollers as the rollers rotate. In other words, the feed mechanism 41 functions as a transport mechanism for the media M. In other words, the transport direction of the media M is along the X direction. During normal printing, the feed mechanism 41 feeds the media M from the rear side to the front side of the printing device 2. Therefore, in the following description, the "transport direction" refers to the direction from the rear side to the front side in the X direction. The "upstream side in the transport direction" refers to the rear side of the printing device 2, and the "downstream side in the transport direction" refers to the front side of the printing device 2.

[0024] As shown in FIG. 1 , the printing device 2 has a media M feed unit 6 and a media M take-up unit 7. The unprinted media M is wound around the feed unit 6, and the media M is fed toward the printing unit 3 by driving a feed mechanism 41. The take-up unit 7 takes up the media M printed by the printing unit 3 into a roll. The feed unit 6 is located behind the frame 5 supporting the printing unit 3 and the platen 4 in the X direction, and the take-up unit 7 is located in front. The feed unit 6 and the take-up unit 7 are located below the printing unit 3 and the platen 4. The feed unit 6 includes a shaft 61 that supports the rolled media M and a roller 62 that guides the media M fed from the shaft 61 between the printing unit 3 and the platen 4. The shaft 61 is rotatable around a central axis Y1. A core is inserted around the shaft 61, and the media M is wound around the outer periphery of the core.

[0025] The winding unit 7 includes a shaft 71 for winding the printed medium M into a roll, and a roller 72 for guiding the medium M toward the shaft 71 after it has passed between the printing unit 3 and the platen 4. The shaft 71 is rotatable about a central axis Y2. The central axis Y2 of the shaft 71 extends parallel to the central axis Y1 of the shaft 61 on the side of the feeding unit 6. A core is fitted around the shaft 71, and the medium M is wound around the outer periphery of the core.

[0026] The printing device 2 drives the delivery mechanism 41 to pay out the medium M from the payout unit 6 and supply it between the platen 4 and the printing unit 3. The printing device 2 prints on the medium M by repeating the following operations: transporting the medium M a predetermined distance in the transport direction, and moving the head unit 34 mounted on the carriage 32 in the Y direction to eject ink at a specified position on the printing surface of the medium M. After printing, the medium M is transported further downstream in the transport direction and taken up by the take-up unit 7.

[0027] FIG. 2 is a schematic diagram showing the configuration of the head unit 34. FIG. 2 shows the head unit 34 as viewed from below. As shown in FIG. 2, the head unit 34 includes two inkjet heads 35 and 36 (hereinafter simply referred to as "heads 35 and 36"). The heads 35 and 36 are arranged in a staggered arrangement, with offset positions in the X and Y directions. When viewed from above the printing device 2 (see FIG. 4), the head 36 is located to the left of the head 35 in the Y direction and in front of the printing device 2 in the X direction (see FIG. 1). In other words, the head 36 is located downstream of the head 35 in the transport direction of the medium M. Note that the head 36 may also be located to the right of the head 35 in the Y direction.

[0028] The head 35 (first head) has four nozzle portions 351 to 354 aligned in the Y direction. The head 36 (second head) also has four nozzle portions 361 to 364 aligned in the Y direction. For ease of understanding, the nozzle portions 351 to 354 are cross-hatched and the nozzle portions 361 to 364 are hatched in Figure 2. The nozzle portions 351 to 354 and 361 to 364 are provided on the bottom surfaces (surfaces facing the media M) of the heads 35 and 36, respectively.

[0029] As shown in the enlarged area of ​​Figure 2, each nozzle section is made up of a plurality of nozzle rows Nq. Each nozzle row Nq is made up of a plurality of nozzles N arranged at regular intervals in the X direction. A single nozzle section is formed by arranging these plurality of nozzle rows Nq at intervals in the Y direction. Although not shown in the figure, the heads 35 and 36 are provided with piezo elements corresponding to each of the nozzles provided in the nozzle sections 351 to 354 and nozzle sections 361 to 364. Ink is ejected from the nozzles by driving the piezo elements of each nozzle.

[0030] Ink is supplied to each of the nozzle units 351 to 354 and 361 to 364 from an ink supply mechanism (not shown). The ink supply mechanism can supply different types of ink to the nozzle units 351 to 354 and 361 to 364 depending on the settings of the printing device 2. The ink can be, for example, C (cyan), M (magenta), Y (yellow), and K (black) process color inks (hereinafter referred to as "color inks"). Alternatively, the ink can be a special color ink such as LC (light cyan), LM (light magenta), Gy (gray), W (white), CL (clear), Pr (primer), O (orange), violet, metallic colors (gold, silver), or fluorescent colors.

[0031] 2 shows an example in which color ink is supplied to the nozzle portion of head 35, and spot color ink is supplied to the nozzle portion of head 36. In the example of Fig. 2, M (magenta) ink is supplied to nozzle portion 351 of head 35, C (cyan) ink is supplied to nozzle portion 352, Y (yellow) ink is supplied to nozzle portion 353, and K (black) ink is supplied to nozzle portion 354. Also, in the example of Fig. 2, CL (clear) ink is supplied to nozzle portions 361 and 362 of head 36, and W (white) ink is supplied to nozzle portions 363 and 364.

[0032] Note that FIG. 2 is merely an example, and settings such as the number and arrangement of heads, the nozzle portion of each head, the nozzle row, the number and arrangement of nozzles, and the allocation of ink colors to each nozzle portion can be changed as appropriate.

[0033] The printing device 2 is capable of printing images in which multiple ink layers are superimposed. FIG. 3A is a diagram showing an example of a print of an image in which multiple ink layers are superimposed, and FIG. 3B is a cross-sectional view taken along the line A-A in FIG. 3A. In the print example of FIG. 3, an ink layer L1 formed with color ink from the head 35 is superimposed on an ink layer L2 formed with a special color ink (clear ink) from the head 36. Note that in FIG. 3B, the thicknesses of the ink layers L1 and L2 are exaggerated for clarity. Superimposing an ink layer L2 formed with clear ink on an ink layer L1 formed with color ink can impart a glossy appearance to the image. Furthermore, when printing on a transparent medium M, an ink layer L2 formed with white ink can be superimposed on an ink layer L1 formed with color ink. In this case, the image is viewed from the side of the medium M opposite the printed surface, and the white ink of the ink layer L2 serves as a base, allowing the color ink of the ink layer L1 to be clearly visible. Note that Figure 3 shows an example in which the ink layer L1 and the ink layer L2 have the same shape and size, and the ink layer L2 overlaps the entire ink layer L1, but the multiple ink layers may have different shapes or sizes and may partially overlap each other.

[0034] Fig. 4 is a diagram illustrating a method for printing the image in Fig. 3. Fig. 4 shows the printing device 2 as viewed from above. Note that Fig. 4 is a schematic diagram, and the size of the heads 35, 36 is exaggerated relative to the medium M. As shown in Fig. 4(a), the printing device 2 moves the carriage 32 in the Y direction and ejects color ink from the head 35 to form an ink layer L1.

[0035] Next, as shown in FIG. 4B , the printing device 2 advances the printing area PA of the ink layer L1 on the medium M to the position of the head 36 downstream in the transport direction. The printing area PA includes the ink layer L1 and its surrounding area and can be set appropriately based on the specifications of the image data created by the information processing device 10 (described later) and the specifications of the printing device 2. The printing device 2 moves the carriage 32 in the Y direction and ejects clear ink from the head 36 to form the ink layer L2 on top of the ink layer L1. Note that the illustrated example shows an example in which the ink layers L1 and L2 can be formed in one reciprocating movement (one pass) of the heads 35 and 36 in the Y direction. Depending on the size of the image, the printing device 2 can form the ink layers L1 and L2 by alternately advancing the medium M a predetermined distance downstream in the transport direction and moving the carriage 32 in the Y direction to eject color ink from the head 35.

[0036] FIG. 5A shows another example of a printed image in which multiple ink layers are superimposed, and FIG. 5B shows a cross-sectional view of FIG. 5A taken along the line A-A. In the example print shown in FIG. 5, an ink layer L1 formed with color inks from the head 35 is superimposed on an ink layer L2 formed with a special color ink (white ink) from the head 36. Note that the thicknesses of the ink layers L1 and L2 are exaggerated in FIG. 5B. This type of printing is performed, for example, when white ink is used as a base. For example, if the medium M is a dark color, even if an image is printed by ejecting color inks directly onto the medium M, the color of the medium M may affect the image color, making it difficult to see properly. Therefore, by superimposing an ink layer L1 of color inks on an ink layer L2 formed with white ink as a base, the influence of the color of the medium M is reduced, making it easier to see the image color properly. The ink layer L1 of the special color ink may also be formed using, for example, a primer (Pr). The primer ink can be used, for example, as a base for other inks. If the primer ink has adhesive properties, it can be used as a glue to adhere color ink, foil, etc. to media.

[0037] FIG. 6 is a diagram illustrating a printing method for the image in FIG. 5 . Note that FIG. 6 is a schematic diagram, and the size of the heads 35 and 36 is exaggerated relative to the medium M. As shown in FIG. 6A, the printing device 2 moves the carriage 32 in the Y direction and ejects white ink from the head 36 to print the ink layer L2. Next, as shown in FIG. 6B, the printing device 2 pulls back the printing area PA of the ink layer L2 on the medium M to the position of the head 35 on the upstream side in the transport direction. The printing device 2 then moves the carriage 32 in the Y direction and ejects color inks from the head 35 to form ink layer L1 over ink layer L2. In this way, when ink layer L1 is first printed by the head 36 and then ink layer L1 is printed by the head 35, an operation of pulling back the medium M upstream in the transport direction occurs after printing of ink layer L2. Hereinafter, printing that includes an operation of pulling back the medium M upstream in the transport direction will be referred to as "pullback printing." When pulling the media M back upstream in the transport direction, it is necessary to reverse the rotation of the rollers of the delivery mechanism 41 (see FIG. 1) and wind the media M around the feeding unit 6. In the printing device 2, the media M is transported with its longitudinal direction aligned with the X direction, but when the media M is wound around the feeding unit 6, the media M may become slightly tilted with respect to the X direction. This tilting of the media M also causes the ink layer L2 formed on the media M to become tilted. As shown in FIGS. 5A and 6, when performing pullback printing, the printing device 2 prints a mark mk on the media M to detect the tilt of the ink layer L2 that was initially formed.

[0038] As described above, the carriage 32 is equipped with a sensor 38 for detecting the mark mk. The sensor 38 can be, for example, a reflective optical sensor. Although not shown, the optical sensor includes a light-emitting unit and a light-receiving unit that receives light emitted from the light-emitting unit and reflected by the medium M. The sensor 38 is positioned so that it can detect the mark mk when the medium M is returned upstream in the transport direction. For example, as shown in FIG. 6A , the sensor 38 can be positioned below the carriage 32, near the head 35. In this case, the sensor 38 can detect the mark mk printed on the medium M by scanning the printing surface of the medium M while moving the carriage 32 in the Y direction. Note that the sensor 38 may be positioned separately from the carriage 32. In this case, the sensor 38 may be equipped with a drive mechanism separate from the drive mechanism of the carriage 32. Alternatively, the sensor 38 may be a camera that captures image information of the medium M.

[0039] As shown in FIG. 5A, the mark mk is printed near the ink layer L2. The mark mk can be printed, for example, at the four corners of the printing area PA of the ink layer L2 so as to surround the ink layer L2. Note that at least a portion of the mark mk may extend inside the printing area PA to the extent that it does not affect the image. For example, as shown in the enlarged area of ​​FIG. 5A, the mark mk can include a line segment S1 extending in one direction and a line segment S2 extending in a direction perpendicular to the line segment S1. The example of FIG. 5A shows a mark mk in which one end of the line segment S1 is connected to one end of the line segment S2. The shape of the mark mk is not limited to this. For example, the mark mk may be a cross shape, where the line segments S1 and S2 intersect. The mark mk may also include, for example, only the line segment S1 or only the line segment S2.

[0040] When the medium M is not tilted, the line segment S1 of the mark mk is aligned along the X direction, and the line segment S2 is aligned along the Y direction. If the medium M is tilted during the pullback printing described above, the line segments S1 and S2 of the mark mk will be tilted relative to the X and Y directions, respectively. In other words, the tilt of the line segments S1 and S2 can be considered as the tilt of the ink layer L2.

[0041] It should be noted that the marks mk may be any marks that can be detected by the sensor 38, and the number, shape, and arrangement of the marks mk are not limited to the example shown in the figure and can be changed as appropriate. The marks mk can also be used as marks that indicate the cutting position of the medium M after printing. For example, as shown in FIG. 5A, if the marks mk are printed so as to surround the ink layer L2 and the medium M is cut at the position of the marks mk, the marks mk will not remain on the medium M after cutting. This prevents the marks mk from affecting the finished print.

[0042] The mark mk can be printed with ink that can be detected by the sensor 38. For example, if the medium M is white and the spot color ink ejected by the head 36 is white or clear, the mark mk printed with these inks will be difficult for the sensor 38 to detect. In such a case, the mark mk can be printed with any of the CMYK (black) color inks ejected by the head 35. In this case, as shown in FIG. 6A , the printing device 2 prints the mark mk in the printing area PA of the ink layer L2 with the head 35 on the upstream side in the transport direction, and then sends the printing area PA to the position of the head 36, where the ink layer L2 can be formed by the head 36.

[0043] Alternatively, if the spot color ink ejected by the head 36 can be detected by the sensor 38, the mark mk may be printed by the head 36. In this case, the printing device 2 can feed the medium M to the position of the head 36 and print the mark mk together with the ink layer L2 by the head 36.

[0044] For example, if an optical sensor 38 is mounted on the carriage 32, after printing the ink layer L2, the printing device 2 moves the carriage 32 in the Y direction while using the delivery mechanism 41 to pull the medium M back upstream in the transport direction, and detects the mark mk with the sensor 38. The sensor 38 inputs position information (XY coordinates) of the detected mark mk to the controller 8 (see FIG. 1).

[0045] The controller 8 can be configured, for example, by a microcomputer equipped with a processor and memory. The controller 8 is communicatively connected to the information processing device 10 via a LAN cable or the like. The controller 8 receives print data for controlling the operation of the printing device 2 from the information processing device 10. Based on the print data, the controller 8 controls operations such as the movement of the carriage 32 by the drive mechanism, the transport of the medium M by the feed mechanism 41, the ejection of ink from the heads 35 and 36, and the detection of the marks (mk) by the sensor 38. The controller 8 also transmits position information of the marks (mk) detected by the sensor 38 to the information processing device 10.

[0046] FIG. 7 is a block diagram showing the functional configuration of the information processing device 10. The information processing device 10 can be a general-purpose information processing device 10 such as a personal computer, a mobile phone, or a tablet terminal. Although not shown, the information processing device 10 includes a processor such as a central processing unit (CPU) and memories such as a hard disk drive (HDD), a solid state drive (SSD), and a random access memory (RAM). Various software necessary for the operation of the information processing device 10 is installed in the memory. For example, the memory may include software (image creation software) for creating and editing image data (image data) to be printed by a printer, and software (RIP: Raster Image Processor) for creating print data based on the image data. In other words, the information processing device 10 functions as an image processing device that creates image data to be printed on the medium M. The information processing device 10 also functions as a control device that controls the operation of the printing device 2 by transmitting the created print data to the printing device 2. Various data necessary for creating the image data and print data is also stored in the memory of the information processing device 10.

[0047] The information processing device 10 also includes a display device such as a liquid crystal display, and an input device such as a mouse, a keyboard, a touch panel, etc. The information processing device 10 displays an operation screen for creating image data and print data on the display device, and accepts operation inputs from the user via the input device.

[0048] As shown in Fig. 7, the information processing device 10 has, as its functional configuration, an image data creation unit 11, a job management unit 12, a print data creation unit 13, and a correction unit 14. The image data creation unit 11 creates image data to be printed on a medium M by a printer. The created image data is stored in the memory of the information processing device 10. As shown in Figs. 3 and 5, when printing an image in which multiple ink layers are superimposed, the image data is composed of multiple layers including images formed by each ink layer.

[0049] A user can upload image data to be printed on the medium M and specify various printing conditions via an operation screen provided by the software of the information processing device 10. The uploaded image data is not limited to that created by the image data creation unit 11 and may be that created by another information processing device 10. The job management unit 12 creates a print job based on the image data uploaded by the user and the specified printing conditions and registers it in a job list. The job management unit 12 manages the progress of each print job registered in the job list and reflects the printing progress status in the job list. FIG. 8 is a diagram showing an example of a job list. As shown in FIG. 8, the job list contains information such as the job name, a thumbnail of the image to be printed, and job attributes. When a user selects a print job to be executed from the job list and inputs an instruction to start printing, the job management unit 12 outputs the image data and printing conditions of the specified print job to the print data creation unit 13 and creates print data. The job management unit 12 sends the created print data to the controller 8 of the printing device 2 to start printing. When the job management unit 12 receives a notification of the completion of printing from the controller 8, it updates the job list and deletes the completed print job.

[0050] The print data creation unit 13 (see FIG. 7 ) performs the print data creation step. Based on the image data, the print data creation unit 13 creates print data for controlling the operation of the printing device 2. Specifically, the print data creation unit 13 performs RIP processing on the image data input from the job management unit 12 according to the specified printing conditions to create print data. The RIP processing is a process for generating a raster image that specifies the ejection positions for ejecting ink of a color corresponding to the image data. In the RIP processing, a raster image is generated by performing halftone processing on a grayscale image corresponding to each of the color inks (C, M, Y, and K) and the spot color ink. Furthermore, various commands for controlling the printing device 2 according to the specified printing conditions are added to the generated raster image, thereby creating print data.

[0051] When printing an image by overlapping multiple ink layers, as in the print examples of FIGS. 3 and 5 , a composite job that combines multiple print jobs is registered in the job list. FIG. 8 shows an example in which a composite job for printing the image shown in FIG. 5 is registered in the job list. The composite job combines a job (white plate) that forms ink layer L2 using white ink from head 36 and a job (color plate) that forms ink layer L1 using color ink from head 35. The composite job also indicates the layering order of the ink layers. In the example of FIG. 8 , the layering order is the white plate, followed by the color plates. When printing the image shown in FIG. 3 , the layering order is the color plates, followed by the white plate. When executing the composite job, the print data creation unit 13 creates print data for forming each ink layer according to the layering order indicated in the composite job. As described above, since image data is composed of multiple layers, including images formed by each ink layer, the print data creation unit 13 creates print data using layers corresponding to each ink layer in the image data. The job management unit 12 sequentially sends the created print data to the printing device 2. For example, in the composite job shown in Figure 8, the print data creation unit 13 creates print data PDb (second print data) for forming ink layer L2 with head 36 and print data PDa (first print data) for forming ink layer L1 with head 35.

[0052] Furthermore, in the printing example of Fig. 5, pullback printing is performed as described above. Fig. 9 is a diagram illustrating the processing flow of the printing system 1 when executing a composite job that includes pullback printing. As shown in Fig. 9, when pullback printing is performed in a composite job, the print data creation unit 13 adds control data CDa for pullback printing to the print data PDb. As described in Fig. 6B, the control data CDa for pullback printing is control data for, after forming the ink layer L2 with the head 36, returning the printing area PA of the ink layer L2 to the position of the head 35 on the upstream side in the transport direction with the delivery mechanism 41, and detecting the mark mk with the sensor 38.

[0053] The print data creation unit 13 determines whether to add control data CDa to print data PDb based on the layering order of multiple ink layers indicated in the combination job. If the layering order is such that ink layer L2 is formed by head 36 and then ink layer L1 is formed by head 35, the print data creation unit 13 adds control data CDa to print data PDb for forming ink layer L2. If the layering order is such that ink layer L1 is formed by head 35 and then ink layer L2 is formed by head 36, the print data creation unit 13 does not add control data CDa to print data PDb for forming ink layer L2.

[0054] For example, in the printing example of Fig. 5 shown in the compositing job of Fig. 8, the layering order is ink layer L2 (white plate), ink layer L1 (color plate), so the print data creation unit 13 adds control data CDa for pullback printing to the print data PDb for the white plate. On the other hand, in the printing example of Fig. 3, the layering order is ink layer L1 (color plate), ink layer L2 (white plate), so the print data creation unit 13 does not add control data CDa for pullback printing to the print data PDb for the white plate.

[0055] When the layering order indicated in the merging job includes a layering order that requires pullback printing, the print data creation unit 13 adds mark printing control data CDb to the print data for forming the first ink layer. The mark printing control data CDb is control data for printing marks mk on the medium M using the head 35 or 36. In the printing example of FIG. 5 shown in the merging job of FIG. 8, the mark printing control data CDb is added to the print data PDb for forming the first ink layer L2 (white plate).

[0056] As shown in FIG. 9 , when print data PDb is input, the printing device 2 forms an ink layer L2 in accordance with the print data PDb and prints a mark mk in accordance with the mark printing control data CDb. After forming the ink layer L2, the printing device 2 pulls the medium M back upstream in the transport direction in accordance with the pullback printing control data CDa and detects the mark mk. When the printing device 2 completes printing based on the print data PDb, it sends a print completion notification to the information processing device 10. If the printing device 2 detects the mark mk, it includes position information of the mark mk in the print completion notification and sends it to the information processing device 10. The job management unit 12 acquires the position information of the mark mk included in the print completion notification and causes the correction unit 14 to perform a correction process (correction step) on the image data before creating the print data PDa. Specifically, the correction unit 14 corrects the image included in the layer of the image data corresponding to the ink layer L2.

[0057] FIG. 10A illustrates the tilt of the ink layer L2 caused by the retraction of the medium M, and FIG. 10B illustrates an example of image data correction. As mentioned above, the tilt caused by the retraction of the medium M is slight, but the image tilt is exaggerated in the drawing for clarity. FIG. 10A illustrates an example in which the retraction of the medium M causes a tilt of the mark mk at an angle θ. As mentioned above, the tilt of the mark mk can be considered as the tilt of the ink layer L2. The correction unit 14 calculates the tilt angle θ of the mark mk from the position information of the mark mk input from the controller 8 of the printing device 2. As shown in FIG. 10B, the correction unit 14 tilts the image of the layer corresponding to the ink layer L2 in the image data according to the calculated tilt angle θ of the mark mk. The correction unit 14 rotates the entire print area PA of the image by the angle θ around the center of the print area PA as an axis. As a result, the image is tilted by the angle θ. The correction unit 14 uses a known method such as affine transformation to set a new rectangular print area PA (dashed line in the figure) along the X and Y directions that includes the print area PA (dashed line in the figure) of the image that has been tilted due to rotation, thereby creating corrected image data.

[0058] Note that the correction unit 14 does not need to perform correction unless the ink layer L2 has a tilt that affects print quality. Therefore, the correction unit 14 may compare the tilt angle θ of the mark mk input from the controller 8 with a preset threshold value, and perform correction processing if the tilt angle θ exceeds the threshold value.

[0059] Note that the correction method using the tilt angle θ of the mark mk is merely one example, and the correction unit 14 can correct the image data using various methods based on the position information of the mark mk. For example, if the printing device 2 uses thermosetting or ultraviolet-curable ink, it is possible that the medium M or the ink layer L2 will shrink slightly during heating or ultraviolet irradiation. In this case, the correction unit 14 may calculate the reduction ratio of the mark mk from the position information of the mark mk and reduce the image of the image data according to that reduction ratio. Alternatively, when the medium M is pulled back, the mark mk may not tilt, but may be displaced in the X or Y direction. The correction unit 14 may calculate the amount of positional deviation from the position information of the mark mk and move the position of the image of the image data according to the amount of positional deviation.

[0060] 9, the print data creation unit 13 performs RIP processing on the corrected image data to create print data PDa for forming ink layer L1 with the head 35. As described above, the RIP processing generates a raster image that specifies the ejection positions of ink of the color corresponding to the image data. That is, the print data creation unit 13 creates print data PDa from the image data corrected to match the tilt of ink layer L2, and the printing device 2 forms ink layer L1 in accordance with the print data PDa, so that the ejection positions of ink in ink layer L1 properly overlap the tilted ink layer L2.

[0061] While FIGS. 3 and 5 illustrate examples of printing images with two ink layers stacked on top of each other, the number of stacked ink layers is not limited to two and can be varied as appropriate. FIG. 11 illustrates an example of printing an image with three or more ink layers stacked on top of each other. When printing these images, the printing device 2 performs printing including pull-back printing. In FIG. 11(a), an image is printed with three ink layers stacked on top of each other on a transparent medium M. The stacking order is a color ink ink layer L1a, a white ink ink layer L2, and a color ink ink layer L1b. The ink layers L1a and L1b are formed using image data that is inverted relative to each other. This allows the same image to be viewed from both sides of the transparent medium M. In this case, the printing device 2 forms the ink layer L1a with the head 35, then sends the medium M downstream in the transport direction and forms the ink layer L2 with the head 36. After forming the ink layer L2, the printing device 2 performs pull-back printing to form the ink layer L1b with the head 35 located upstream in the transport direction. The printing device 2 can print the mark mk when first forming the ink layer L1a with the head 35. After forming the ink layer L2, the printing device 2 detects the mark mk with the sensor 38 when retracting the medium M, and the information processing device 10 corrects the image data according to the position information of the mark mk and creates print data PDa using the corrected image data.

[0062] In (b) of FIG. 11, an image is printed by overlapping four ink layers on a transparent medium M. The layering order is a color ink ink layer L1a, a white ink ink layer L2a, a color ink ink layer L1b, and a clear ink ink layer L2b. As in (b) of FIG. 11, the ink layers L1a and L1b are formed using mutually inverted image data. The clear ink ink layer L2b can be formed as a protective layer. In (b) of FIG. 11, the printing device 2 forms the ink layers L1a, L2a, and L1b in the same manner as in (a) of FIG. 11. The printing device 2 further feeds the medium M downstream in the transport direction and forms the ink layer L2b with the head 36.

[0063] In (c) of FIG. 11, an image is printed on a transparent medium M by stacking five ink layers. The layering order is a color ink layer L1a, a white ink layer L2a, a black ink layer L1b, a white ink layer L2b, and a color ink layer L1c. In (c) of FIG. 11, a black ink layer L1b, which serves as a shielding layer, is formed in the center, allowing different images to be viewed from one side and the other side of the transparent medium M. The color ink layers L1a and L1b are formed using different image data. The white ink layers L2a and L2b serve as bases for the ink layers L1a and L1c, respectively. The printing example in (c) of FIG. 11 includes two pullback printing operations: one when forming the ink layer L2a after the ink layer L1a, and one when forming the ink layer L2b after the ink layer L1b. In each pullback printing, the marks (mk) are detected and the image data is corrected according to the position information of the marks (mk), and the print data (PDa) is created using the corrected image data. By detecting the marks (mk) and correcting the image data each time pullback printing is performed, it is possible to appropriately overlay multiple ink layers with reduced misalignment.

[0064] In any of the cases shown in FIGS. 11A to 11C, the printing device 2 can print the marks mk using the head 35 or the head 36 when forming the first ink layer.

[0065] Fig. 12 is a flowchart showing the flow of processing in the information processing apparatus 10. Note that Fig. 12 explains processing from a state in which a print start instruction for a composite job registered in the job list (see Fig. 8) is input by the user.

[0066] The job management unit 12 determines whether pullback printing is necessary by referring to the stacking order indicated in the composite job (step S01). If the stacking order includes a stacking order in which ink layer L1 is formed after ink layer L2 is formed, the job management unit 12 determines that pullback printing is necessary (step S01: Yes) and proceeds to the pullback printing process from step S02 onwards. If the stacking order does not include a stacking order in which ink layer L1 is formed after ink layer L2 is formed, the job management unit 12 determines that pullback printing is not necessary (step S01: No) and proceeds to the normal printing process. In normal printing, the job management unit 12 causes the print data creation unit 13 to create print data for each job according to the stacking order, and sequentially sends the data to the printing device 2 to proceed with printing. Details of normal printing are omitted.

[0067] In step S02, the job management unit 12 sets the number of jobs N included in the composite job to an initial value of n = 1 and starts the nth job. The number of jobs N corresponds to the number of ink layers (number of layers) forming the image printed on the media. The job management unit 12 then causes the print data creation unit 13 to create print data for the nth job (step S03). The print data creation unit 13 then performs RIP processing according to the specified printing conditions on the image of the layer corresponding to the ink layer formed by the nth job in the image data input from the job management unit 12, thereby creating print data. If the currently executing nth job is to form ink layer L2 and the next (n+1)th job is to form ink layer L1 (step S04: Yes), the print data creation unit 13 creates print data PDb and adds control data CDa for pullback printing to this print data PDb (step S05).

[0068] Furthermore, if the nth job being executed is the first job (n=1) (step S06: Yes), the print data creation unit 13 adds control data CDb for printing marks to the print data to be created (step S07). When adding control data CDb to print data PDa, the control data CDb has content to print marks mk while forming ink layer L1 with head 35. When adding control data CDb to print data PDb, the control data CDb has content to print marks mk with head 35 before forming ink layer L2 with head 36.

[0069] The print data creation unit 13 creates print data by executing the print data creation steps of steps S04 to S07. The job management unit 12 sends the created print data to the printing device 2 (step S08). When the job management unit 12 receives a print completion notification from the printing device 2 (step S09: Yes), it determines whether the number of executed nth jobs has reached N. If n=N is not true (step S10: No), the job management unit 12 sets n=n+1 (step S11) and starts the next job.

[0070] As described with reference to FIG. 9 , when pullback printing is being performed on the printing device 2, the print completion notification includes position information of the mark mk. If the print completion notification includes position information of the mark mk (step S12: Yes), the job management unit 12 inputs the position information of the mark mk to the correction unit 14. The correction unit 14, for example, calculates the tilt angle θ from the position information of the mark mk. The correction unit 14 corrects the image data by tilting the image of the layer corresponding to the ink layer formed in the nth job in the image data according to the calculated tilt angle θ (step S13, correction step). The job management unit 12 proceeds to step S03 and causes the print data creation unit 13 to create print data for the next job. Here, if correction processing has been performed in step S13, the print data creation unit 13 creates print data using the corrected image data. If the print completion notification does not include position information of the mark mk (step S12: No), the job management unit 12 proceeds to step S03 without correcting the image data and starts the next job. In this case, the print data creation unit 13 creates print data using uncorrected image data. Although not shown in the flowchart, as described above, the correction unit 14 may compare the calculated tilt angle θ of the mark mk with a preset threshold value and perform correction processing only if the calculated tilt angle θ exceeds the threshold value. The job management unit 12 repeats the processes of steps S03 to S13 to sequentially execute each job included in the composite job. When the nth job that has been executed reaches the job number N (step S10: Yes), the job management unit 12 ends the process.

[0071] As described above, the printing system 1 described in the embodiment has, for example, the following configuration: (1) The printing system 1 includes a printing device 2 capable of printing an image in which multiple ink layers are superimposed on a medium M, and an information processing device 10 (control device) that controls the operation of the printing device 2. The printing device 2 includes: a feed mechanism 41 (transport mechanism) that transports the medium M; a head 35 (first head) equipped with nozzles that eject ink onto the medium M; a head 36 (second head) equipped with nozzles that eject ink onto the medium M and shifted downstream in the transport direction of the medium M relative to the head 35; and a sensor 38 that detects marks mk printed on the medium M. The information processing device 10 includes: a print data creation unit 13 that creates print data for controlling the operation of the printing device 2 based on image data (image data), and a correction unit 14 that corrects the image data based on position information of the marks mk detected by the sensor 38. When printing an image in which an ink layer L1 formed by the head 35 is superimposed on an ink layer L2 formed by the head 36, the print data creation unit 13 adds control data CDa (control data) for pullback printing to the print data PDb (second print data) for forming the ink layer L2 by the head 36, so that after the ink layer L2 is formed by the head 36, the feed mechanism 41 returns the ink layer L2 to the position of the head 35 upstream in the transport direction and the sensor 38 detects the mark mk. The print data creation unit 13 creates print data PDa (first print data) for forming the ink layer L1 by the head 35 using the image data corrected by the correction unit 14. Specifically, the correction unit 14 creates the print data PDa using a layer corresponding to the ink layer L2 corrected by the correction unit 14.

[0072] The printing system 1 of this embodiment reduces misalignment of ink layers and reduces the impact on print quality when performing pullback printing on the medium M. In the printing device 2, when printing an ink layer L1 formed by the head 35 over an ink layer L1 formed by the head 36, the ink layer L2 formed on the medium M by the head 36 needs to be pulled back to the position of the head 35, which is upstream in the transport direction. When pulling the medium M back upstream in the transport direction, the medium M may tilt slightly, causing the ink layer L1 printed on the medium M to also tilt. Printing the ink layer L2 with the ink layer L1 tilted may prevent the multiple ink layers from overlapping properly, resulting in misalignment and potentially affecting print quality. In this embodiment, when printing an image in which the ink layer L1 formed by the head 35 is overlaid on the ink layer L2 formed by the head 36 in the printing device 2, the information processing device 10 adds pullback printing control data CDa to the print data PDb (second print data) for forming the ink layer L2 by the head 36. When the printing device 2 retracts the medium M after forming the ink layer L2 in accordance with the control data CDa, the sensor 38 detects the mark mk printed on the medium M. The correction unit 14 of the information processing device 10 corrects the image data based on the position information of the detected mark mk. The print data creation unit 13 creates print data PDa for forming the ink layer L1 based on the corrected image data. This allows the printing device 2 to properly overlay the ink layer L1 on the tilted ink layer L2, reducing misalignment.

[0073] In the above embodiment, an example has been described in which the correction unit 14 calculates the tilt angle θ of the mark mk from the position information of the mark mk, but the controller 8 of the printing device 2 may calculate the numerical values ​​necessary for correction of the tilt angle θ, etc. from the position information of the mark mk, and transmit them to the information processing device 10.

[0074] (2) The print data creation unit 13 determines whether to add control data CDa for pullback printing to the print data PDb based on the layering order of the multiple ink layers that make up the image.

[0075] The printing device 2 may print an image in which three or more ink layers are superimposed. The print data creation unit 13 determines whether to add control data CDa for pullback printing based on the layering order indicated in the composite job, so that even when three or more ink layers are superimposed, the sensor 38 can detect the mark mk and the correction unit 14 can correct the image data each time the medium M is pulled back. This allows multiple ink layers to be printed in an appropriate superimposed manner.

[0076] (3) When, in the stacking order, ink layer L1 is formed by head 35 after ink layer L2 is formed by head 36, print data creation unit 13 adds control data CDa for pullback printing to print data PDb for forming ink layer L2 by head 36. When, in the stacking order, ink layer L1 is formed by head 35 after ink layer L2 is formed by head 36, print data creation unit 13 does not add control data CDa for pullback printing to print data PDb for forming ink layer L2 by head 36.

[0077] When printing an image in which multiple ink layers are superimposed, when ink layer L1 is superimposed on ink layer L2, it is necessary to pull back the medium M, but when ink layer L2 is superimposed on ink layer L1, it is not necessary to pull back the medium M. The print data creation unit 13 determines whether or not to add control data CDa for pullback printing based on the stacking state in the stacking order, thereby enabling appropriate control of the printing device 2.

[0078] (4) If the stacking order of the multiple ink layers that make up the image includes a stacking order in which ink layer L2 is formed by head 36 and then ink layer L1 is formed by head 35, the print data creation unit 13 adds control data CDb for mark printing to the print data for forming the first ink layer, for printing mark mk on medium M by head 35 or head 36.

[0079] When the printing device 2 performs pullback printing, by printing a mark mk on the medium M when the first ink layer is formed, the same mark mk can be used for processing each time the medium M is pulled back thereafter, thereby simplifying the processing.

[0080] (5) The print data includes information specifying the ink ejection position on the medium M. The correction unit 14 corrects the image data by tilting the image in accordance with the tilt angle θ of the mark mk detected by the sensor 38.

[0081] The inclination of the mark mk printed on the medium M reflects the inclination of the ink layer L2. The correction unit 14 corrects the image data by tilting the image of the image data in accordance with the inclination angle θ of the mark mk, and in the print data PDa for the ink layer L1 created from the corrected image data, the ink ejection position is specified so that it overlaps the inclined ink layer L2. This allows multiple ink layers to be printed in an appropriate overlapping manner, reducing misalignment of the ink layers and improving print quality.

[0082] (6) The sensor 38 is disposed on the carriage 32 that carries the heads 35 and 36 and is movable in the Y direction perpendicular to the transport direction. The printing device 2 detects the marks mk printed on the medium M using the sensor 38 while moving the carriage 32 in the Y direction perpendicular to the transport direction.

[0083] For example, by placing an optical sensor 38 on the carriage 32, the sensor 38 can be moved in the Y direction by the carriage 32 while scanning the medium M to detect the marks mk. This allows a small sensor 38 to be used, making it possible to make the printing device 2 more compact and reducing the cost of the sensor 38.

[0084] (7) The controller 8 of the printing device 2 causes the head 35 or the head 36 to print the mark mk at a position surrounding the ink layer L2 formed by the head 36.

[0085] By printing the marks mk in positions that surround the ink layer L2, the inclination of the marks mk is more likely to reflect the inclination of the ink layer L2, thereby improving the accuracy of the correction process by the correction unit 14. Furthermore, by printing the marks mk so as to surround the ink layer L2, the marks mk can be used not only for correcting the image data, but also to indicate the cutting position of the medium M after printing.

[0086] The above-described effects can also be applied to a control method for controlling the printing device 2. In the embodiment, an example has been described in which the functions of the control device of the printing system 1 are realized by the information processing device 10, but the present invention is not limited to this example. The functions of the control device may also be realized by the controller 8 of the printing device 2. In this case, the controller 8 of the printing device 2 includes a hardware RIP that performs RIP processing on image data to create print data.

[0087] (Variation 1) Fig. 13 is a schematic diagram showing the configuration of a printing system 1A according to Variation 1. As shown in Fig. 13, the printing system 1A according to Variation 1 includes a printing device 2 and an information processing device 10, similar to the embodiment. In Variation 1, the same components as those in the above-described embodiment are given the same reference numerals, and detailed description thereof will be omitted. The functional configuration of the information processing device 10 in Variation 1 is the same as that in Fig. 7, and therefore is not shown. Also, in Fig. 13, the platen 4 of the printing device 2 and the stand 5 supporting the printing unit 3 are not shown.

[0088] 13 , the printing device 2 of the printing system 1A according to the first modification has a transfer unit 9 (transfer section) that transfers foil onto the medium M. The transfer unit 9 is disposed between the printing section 3 and platen 4 and the winding section 7 in the transport direction of the medium M. The transfer unit 9 can be removably installed in the printing device 2 as an option, for example.

[0089] The transfer unit 9 presses a foil transfer sheet FS, in which foil is formed on a substrate, against the medium M, transferring the foil to the portion of the medium M onto which the adhesive ink has been ejected. In Modification 1, an example in which an adhesive primer ink is used will be described as an example of the adhesive ink. Foil includes not only metal foil made by beating and stretching metal into a thin sheet, but also metal, resin, glass, etc. powders and pieces of paper solidified into a thin sheet.

[0090] 13, the transfer unit 9 includes a pair of transfer rollers 91a, 91b, a transfer roller 92 that pays out a foil transfer sheet FS relative to the transfer rollers 91a, 91b, and a foil winding unit 95 that winds up the foil transfer sheet FS from the transfer unit. The transfer roller 92 includes a shaft 93 that supports the media M wound in a roll, and a roller 94 that guides the foil transfer sheet FS paid out from the shaft 93 between the pair of transfer rollers 91a, 91b. A core is inserted around the shaft 93, and the foil transfer sheet FS is wound around the outer periphery of the core.

[0091] The foil winding unit 95 includes a shaft 96 for winding the foil transfer sheet FS into a roll after transfer and a roller 97 for guiding the foil transfer sheet FS toward the shaft 96 after it has passed between the pair of transfer rollers 91a and 91b. The shaft 96 of the foil winding unit 95 rotates around the central axis Y4 by a drive mechanism (not shown) to wind up the foil transfer sheet FS. A core is inserted around the shaft 96, and the foil transfer sheet FS is wound around the core. In response to the movement of the foil transfer sheet FS caused by the rotation of the shaft 96 of the foil winding unit 95, the shaft 93 of the transfer roller 92 rotates around the central axis Y3, unwinding the foil transfer sheet FS toward the transfer rollers 91a and 91b. In addition to the control described in the embodiment, the controller 8 of the printing device 2 also controls the drive mechanism of the shaft 96.

[0092] A foil transfer sheet FS unwound from the foil winding unit 95 and a medium M transported downstream in the transport direction from the printing unit 3 are sandwiched between a pair of transfer rollers 91 a, 91 b. Between the pair of transfer rollers 91 a, 91 b, the surface of the foil transfer sheet FS on which the foil is formed faces the printed surface of the image on the medium M. When the foil transfer sheet FS and the medium M are sandwiched and pressed between the pair of transfer rollers 91 a, 91 b, the foil of the foil transfer sheet FS peels off from the substrate and adheres to the portion of the medium M on which the primer ink was ejected.

[0093] Even in Variation 1, it is possible to print an image in which multiple ink layers, including a foil transfer layer, are superimposed. FIG. 14A shows an example of an image printed using the transfer unit 9, and FIG. 14B is a cross-sectional view taken along the line A-A in FIG. 14A. In the printing example of FIG. 14, foil F is transferred to an area where adhesive primer ink Pr has been ejected to form a foil transfer layer L3, and an ink layer L1 formed with color ink is superimposed on the foil transfer layer L3 to form an image. Also, in the printing example of FIG. 14, the foil transfer layer L3 has a different shape and size from the ink layer L1, and the ink layer L1 partially overlaps the foil transfer layer L3. FIG. 14 is merely an example, and the layering order and number of layers are not limited. For example, an ink layer L2 formed with a special color ink may be superimposed on the foil transfer layer L3. For example, by superimposing an ink layer L2 of clear ink on the foil transfer layer L3, the foil F can be protected and less likely to peel off. Alternatively, three or more ink layers L1 and L2 may be superimposed on the foil transfer layer L3. In addition, the ink layer L1 or the ink layer L2 may be formed under the foil transfer layer L3.

[0094] Fig. 15 is a diagram illustrating a method for printing the image in Fig. 14. Note that Fig. 15 is a schematic diagram, and shows the sizes of the heads 35 and 36 in relation to the medium M in an exaggerated manner. As shown in Fig. 15(a), the printing device 2 moves the carriage 32 in the Y direction, and ejects the primer ink Pr onto the medium M using the head 36. The primer ink Pr is ejected onto portions corresponding to the shape of the foil transfer layer L3.

[0095] The printing device 2 further sends the medium M downstream in the transport direction, and the transfer unit 9 transfers the foil F onto the primer ink Pr to form a foil transfer layer L3.

[0096] 15(b), the printing device 2 returns the foil transfer layer L3 of the medium M to the position of the head 35 on the upstream side in the transport direction. The printing device 2 moves the carriage 32 in the Y direction and ejects color ink from the head 35 to form an ink layer L1 that overlaps the foil transfer layer L3.

[0097] As described above, the printing device 2 of Modification 1 may also perform pull-back printing, in which the medium M is pulled back upstream in the transport direction. As described above, the medium M may tilt when pulled back, causing the foil transfer layer L3 formed on the medium M to become tilted. Therefore, as shown in FIG. 15A , the printing device 2 of Modification 1, like the embodiment, prints a mark mk on the medium M using the head 35 or head 36 when forming the foil transfer layer L3. When printing the mark mk using color ink from the head 35, the printing device 2 prints the mark mk in the printing area PA of the foil transfer layer L3 while feeding the medium M downstream in the transport direction, and then forms the foil transfer layer L3 using the head 36 and transfer unit 9. Furthermore, as shown in FIG. 15B , when the printing device 2 pulls the medium M back from the transfer unit 9 to the position of the head 35 upstream in the transport direction, the sensor 38 mounted on the carriage 32 detects the mark mk. The controller 8 of the printing device 2 transmits position information of the mark mk detected by the sensor 38 to the information processing device 10. The correction unit 14 of the information processing device 10 corrects the image data based on the position information of the mark mk. The print data creation unit 13 creates print data PDa for forming the ink layer L1 based on the corrected image data. The manner in which the image data is corrected is the same as that described in Figure 10, so details will be omitted.

[0098] When printing an image by overlapping multiple ink layers including the foil transfer layer L3, a composite job that combines multiple print jobs is registered in the job list (see FIG. 8) of the information processing device 10, as in the embodiment, and the progress of each job is managed by the job management unit 12. The job management unit 12 causes the print data creation unit 13 to create print data for each job, as in the embodiment.

[0099] FIG. 16 is a diagram illustrating the processing flow of the printing system 1A when executing a merging job in Variation 1. As shown in FIG. 16 , when printing the image of FIG. 14 , the print data creation unit 13 creates print data PDc (foil transfer data) for forming the foil transfer layer L3 and print data PDa for forming the ink layer L1. The print data creation unit 13 creates each print data using layers corresponding to each layer constituting the image data. The print data PDc is the content of the print data PDb for forming the ink layer L2 with the head 36, as described in the embodiment, plus control for transporting the ink layer L2 to the transfer unit 9. As in the embodiment, if pullback printing is performed in the merging job, the print data creation unit 13 adds control data CDa for pullback printing to the print data. As in the embodiment, the print data creation unit 13 determines whether to add control data CDa to the print data based on the stacking order of the multiple ink layers indicated in the merging job. 14, when the ink layer L1 or L2 is formed after the foil transfer layer L3 in the stacking order, the print data creation unit 13 adds control data CDa to the print data PDc for forming the foil transfer layer L3. When the ink layer L1 is formed after the ink layer L2 in the stacking order, the print data creation unit 13 also adds control data CDa to the print data PDb for forming the ink layer L2.

[0100] Similarly to the embodiment, if the layering order indicated in the composite job includes a layering order requiring reverse printing, the print data creation unit 13 adds control data CDb for mark printing to the print data for forming the first ink layer. In the print example of FIG. 14 , both control data CDa for reverse printing and control data CDb for mark printing are added to the print data PDc for forming the foil transfer layer L3. As shown in FIG. 16 , upon input of print data PDc, the printing device 2 forms the foil transfer layer L3 according to the print data PDc and prints a mark mk according to the control data CDb for mark printing. After forming the foil transfer layer L3, the printing device 2 retracts the medium M upstream in the transport direction according to the control data CDa for reverse printing and detects the mark mk. The printing device 2 sends a print completion notification to the information processing device 10, including position information for the mark mk. Similarly to the embodiment, the information processing device 10 can acquire the position information from the print completion notification and perform image data correction processing in the correction unit 14.

[0101] As described above, the foil transfer layer L3 may be overlaid with a special color ink layer L2 instead of the color ink layer L1. In this case, after the foil F is transferred in the transfer unit 9, the foil transfer layer L3 is pulled back to the position of the head 36. In this case, the sensor 38 may be disposed not only near the head 35 but also near the head 36 so that the mark mk printed in the printing area PA of the foil transfer layer L3 can be detected at the position of the head 36.

[0102] As described above, the printing system 1A described in Modification 1 has the following configuration. (8) In the printing system 1A, the head 36 of the printing device 2 is capable of ejecting adhesive ink onto the medium M. As the adhesive ink, for example, adhesive primer ink Pr can be used. The printing device 2 includes a transfer unit 9 (transfer section) that is disposed downstream in the transport direction of the head 36 and presses a foil transfer sheet FS, on which foil F is formed on a substrate, against the medium M to transfer the foil F to the portion of the medium M onto which the adhesive ink was ejected. When printing an image by overlaying ink layer L1 or ink layer L2 formed by head 35 or head 36 on foil transfer layer L3 formed by transfer unit 9 transferring foil F to adhesive ink ejected by head 36, print data creation unit 13 adds control data CDa for pullback printing to print data PDc (foil transfer data) for forming foil transfer layer L3, for pulling foil transfer layer L3 back to the position of head 35 or head 36 upstream in the transport direction after foil F is transferred by transfer unit 9, and for detecting mark mk with sensor 38. Print data creation unit 13 creates print data PDa or print data PDb for forming ink layer L1 or ink layer L2 by head 35 or head 36 using image data corrected by correction unit 14.

[0103] In the printing system 1A of Variation 1, for example, after the transfer unit 9 transfers foil F to the primer ink Pr ejected by the head 36 to form the foil transfer layer L3, when the head 35 or head 36 prints the ink layer L1 or L2, the medium M is pulled back to the upstream position of the head 35 or head 36 in the transport direction, which may result in tilting of the foil transfer layer L3. In Variation 1, when the print data creation unit 13 performs the pullback after forming the foil transfer layer L3, it adds control data CDa for pullback printing to the print data PDc for forming the foil transfer layer L3. When the printing device 2 pulls back the medium M after forming the foil transfer layer L3 in accordance with the control data CDa, the sensor 38 detects the marks mk printed on the medium M. The correction unit 14 of the information processing device 10 corrects the image data based on the position information of the detected marks mk. The print data creation unit 13 creates print data PDa or PDb for forming the ink layer L1 or the ink layer L2 based on the corrected image data, which allows the printing device 2 to properly overlay the ink layer on the foil transfer layer L3, thereby reducing misalignment.

[0104] The above-described effects can also be applied to the control method of the printing device 2.

[0105] The present invention is not limited to the above-described embodiment and modified examples, and can be modified as appropriate within the scope of the technical concept of the present invention. Furthermore, the modified examples are not limited to the embodiment, and can be combined with each other.

[0106] REFERENCE SIGNS LIST 1, 1A Printing system 2 Printing device 9 Transfer unit (transfer section) 10 Information processing device (control device) 13 Print data creation section 14 Correction section 35, 36 Inkjet head (head) 38 Sensor 41 Feed mechanism (conveyance mechanism) 100 Processing device 102 Sensor M Media FS Foil transfer sheet Pr Primer ink (adhesive ink) F Foil L1 First layer L2 Second layer mk Mark

Claims

1. A printing system comprising: a printing device capable of printing an image in which a plurality of ink layers are superimposed on a medium; and a control device for controlling the operation of the printing device, wherein the printing device comprises: a transport mechanism for transporting the medium; a first head having a nozzle for ejecting ink onto the medium; a second head having a nozzle for ejecting ink onto the medium and disposed downstream in a transport direction of the medium with respect to the first head; and a sensor for detecting a mark printed on the medium, and the control device comprises: a print data creation unit for creating print data for controlling the operation of the printing device based on data of the image; and a correction unit for correcting data of the image based on positional information of the mark detected by the sensor, wherein the print data creation unit, when printing an image in which an ink layer formed by the first head is superimposed on an ink layer formed by the second head, adds control data to second print data for forming the ink layer with the second head, after forming the ink layer with the second head, for returning the ink layer by the transport mechanism to the position of the first head on the upstream side in the transport direction and for detecting the mark with the sensor, a printing system that creates first print data for forming the ink layer with the first head using the data of the image corrected by the correction unit; 2. A printing system according to claim 1, wherein the print data creation section determines whether to add the control data to the second print data based on the stacking order of the multiple ink layers that make up the image.

3. A printing system as claimed in claim 2, wherein the print data creation unit adds the control data to the second print data for forming an ink layer with the second head if, in the stacking order, an ink layer is formed with the second head after an ink layer is formed with the second head, and does not add the control data to the second print data for forming an ink layer with the second head if, in the stacking order, an ink layer is formed with the second head after an ink layer is formed with the first head.

4. A printing system as described in claim 2, wherein, when the stacking order of the multiple ink layers constituting the image includes a stacking order in which an ink layer is formed by the first head after an ink layer is formed by the second head, the print data creation unit adds control data to the print data for forming a first ink layer for printing the mark on the medium by the first head or the second head.

5. A printing system according to any one of claims 1 to 4, wherein the print data includes information specifying the ink ejection position on the medium, and the correction unit corrects the image data by changing the ink ejection position in accordance with the inclination or positional deviation of the mark detected by the sensor.

6. A printing system according to any one of claims 1 to 4, wherein the sensor is disposed on a carriage which carries the first head and the second head and is movable in a direction perpendicular to the transport direction, and the printing device detects the mark printed on the media by the sensor while moving the carriage in the direction perpendicular to the transport direction.

7. A printing system according to any one of claims 1 to 4, wherein the printing device causes the first head or the second head to print the mark at a position surrounding the ink layer formed by the second head.

8. A printing system according to any one of claims 1 to 4, wherein the first head or the second head is capable of ejecting adhesive ink onto the medium, and the printing device comprises a transfer unit arranged downstream of the second head in the transport direction and pressing a foil transfer sheet having a foil formed on a base material against the medium to transfer the foil, the transfer unit transferring the foil to the adhesive ink to form a foil transfer layer, and overlaying an ink layer formed by the first head or the second head on the foil transfer layer, the print data creation unit, when printing the image by overlaying an ink layer formed by the first head or the second head on a foil transfer layer formed by transferring the foil to the adhesive ink by the transfer unit, adds control data to foil transfer data for forming the foil transfer layer, after the foil is transferred by the transfer unit, for returning the foil transfer layer to the position of the first head or the second head upstream in the transport direction and for detecting the mark by the sensor, and the first print data or the second print data for forming the ink layer by the first head or the second head is created using the data of the image corrected by the correction unit.

9. A control method for a printing device capable of printing an image in which a plurality of ink layers are superimposed on a medium, the printing device comprising: a transport mechanism for transporting the medium; a first head having a nozzle for ejecting ink onto the medium; a second head having a nozzle for ejecting ink onto the medium and disposed downstream in a transport direction of the medium with respect to the first head; and a sensor for detecting a mark printed on the medium, the control method including: a print data creation step for creating print data for controlling an operation of the printing device based on data of the image; and a correction step for correcting the image data based on position information of the mark detected by the sensor, wherein in the printing device, when the image is printed by superimposing an ink layer formed by the first head on an ink layer formed by the second head, in the print data creation step, the mark is printed by the first head or the second head, and after forming the ink layer by the second head, control data is added to second print data for forming the ink layer with the second head, for returning the ink layer to the position of the first head upstream in the transport direction by the transport mechanism, and for detecting the mark by the sensor, A control method for a printing device, comprising: creating first print data for forming the ink layer with the first head using data of the image corrected in the correcting step.

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