Printing method and printing apparatus

Abstract

The invention provides a printing method and a printing apparatus for suppressing bleeding of a transfer image. The printing method includes: an image forming step of forming an image on a transfer medium by discharging colored ink from a first inkjet head; in the substrate forming step, a substrate ink is discharged from a second inkjet head with respect to the transfer medium to overlap the substrate ink on the image, and a region to which the adhesive is supplied at the same timing with respect to the transfer medium in the adhesive applying step is set as a processing unit region. The substrate forming step includes a processing unit region including a first region and a second region in which the substrate ink is superimposed on the image at a later time than the first region. The ejection amount of the base ink per unit area of the second region is made smaller than the ejection amount of the base ink per unit area of the first region.

Description

Technical Field

[0001] The present invention relates to a printing method for performing printing on a transfer medium, and a printing apparatus. Background Art

[0002] As disclosed in Patent Document 1, a printing method for fabric using a transfer sheet as a transfer medium is known. The printing method includes a step of printing first image data on a transfer sheet using black toner and color toner, a step of processing all colors in the printing range of the first image data into black to produce second image data, a step of printing the second image data on the transfer sheet on which the first image data is printed using white toner instead of black toner, a step of applying an adhesive on the uppermost layer of the printed transfer sheet, a step of bonding the transfer sheet coated with the adhesive to the fabric and pressing while heating, and a step of peeling the base material of the transfer sheet.

[0003] In the case of forming an image to be transferred onto a fabric as a transfer medium using an inkjet printer, it is considered to attach a powdery hot-melt adhesive to the image formed by the ink sprayed onto the transfer sheet and transfer the image onto the fabric. For example, by forming an image of colored ink on the transfer sheet, overlapping white ink on the image, attaching the powdery hot-melt adhesive to the white ink, and attaching the heated hot-melt adhesive to the fabric, the image on the transfer sheet can be transferred onto the fabric.

[0004] When the white ink is sprayed onto the image on the transfer sheet, it gradually dries. In the printed area on the transfer sheet, the later the white ink is sprayed, the less the degree of drying of the white ink. Therefore, when the transfer sheet is tilted to apply the powdery hot-melt adhesive or the like, the white ink with a smaller degree of drying sometimes flows downward. If the white ink flows downward, bleeding occurs on the transferred image.

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2014-104595 Summary of the Invention

[0006] The printing method of the present invention has the following mode. That is, in order to perform the adhesive application step and the transfer step to perform printing on a transfer medium, the adhesive application step is a step of attaching an adhesive to a base ink, the base ink being overlapped on an image formed on the transfer medium, and the transfer step is a step of transferring the image onto the transfer medium by attaching the adhesive to the transfer medium. Among them,

[0007] The printing method includes:

[0008] An image forming step of forming the image on the transfer medium by ejecting a colored ink from a first inkjet head;

[0009] A substrate forming step of overlapping the substrate ink on the image by ejecting the substrate ink from a second inkjet head with respect to the transfer medium,

[0010] A region where the adhesive is supplied to the transfer medium at the same timing in the adhesive application step is set as a processing unit region, and the processing unit region includes a first region and a second region where the substrate ink overlaps the image at a later time than the first region.

[0011] In the substrate forming step, the ejection amount of the substrate ink per unit area for the second region is made less than the ejection amount of the substrate ink per unit area for the first region.

[0012] Furthermore, the printing apparatus of the present invention has the following mode, that is, in order to perform the adhesive application step and the transfer step to perform printing on the transfer medium, the adhesive application step is a step of attaching an adhesive to the substrate ink, the substrate ink is overlapped on the image formed on the transfer medium, and the transfer step is a step of transferring the image to the transfer medium by attaching the adhesive to the transfer medium, wherein,

[0013] The printing apparatus includes:

[0014] A first inkjet head that ejects a colored ink;

[0015] A second inkjet head that ejects the substrate ink;

[0016] A drive unit that relatively moves the second inkjet head in a first direction with respect to the transfer medium;

[0017] A control unit that controls the ejection of the colored ink from the first inkjet head, the ejection of the substrate ink from the second inkjet head, and the drive unit,

[0018] The control unit performs the following control, that is, the image is formed on the transfer medium by the colored ink ejected from the first inkjet head, and the substrate ink ejected from the second inkjet head is overlapped on the image,

[0019] An area where the adhesive is supplied at the same timing in the adhesive application process for the transfer medium is set as a processing unit area, and this processing unit area includes a first area and a second area where the base ink overlaps the image at a later time than the first area.

[0020] The control unit makes the ejection amount of the base ink per unit area for the second area less than the ejection amount of the base ink per unit area for the first area. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A diagram schematically showing a structural example of a printing system.

[0022] Figure 2 A top view schematically showing a structural example of a printer.

[0023] Figure 3 A bottom view schematically showing an example of a nozzle surface of an inkjet head.

[0024] Figure 4 A block diagram schematically showing a structural example of a printing apparatus.

[0025] Figure 5 A diagram schematically showing an example of a printing method for a transfer medium.

[0026] Figure 6 A diagram schematically showing an example of area division of a processing unit area.

[0027] Figure 7 A diagram schematically showing an example of side-shift intermittent conveyance.

[0028] Figure 8 A diagram schematically showing an example of a processing unit area in a single sheet of paper.

[0029] Figure 9 A diagram schematically showing an example of area division of a processing unit area corresponding to the conveyance amount per one sub-scan.

[0030] Figure 10 A diagram schematically showing an example of a processing unit area in the case of cutting continuous paper.

[0031] Figure 11 A flowchart schematically showing an example of printing control processing.

[0032] Figure 12 A flowchart schematically showing an example of coefficient setting processing.

[0033] Figure 13A diagram schematically showing an example of changing the amount of base ink ejected according to the size of a continuous region of an image within the same area.

[0034] Figure 14 A diagram schematically showing a structural example of a coefficient table.

[0035] Figure 15 A diagram schematically showing an example of changing the number of cycles according to the amount of base ink ejected per unit area. Detailed implementation manners

[0036] Hereinafter, embodiments of the present invention will be described. Of course, the following embodiments are merely examples of the present invention, and not all the features shown in the embodiments are necessarily required for the solution of the invention.

[0037] (1) Summary of the manners included in the present invention:

[0038] First, with reference to Figures 1 to 15 the examples shown, the summary of the manners included in the present invention will be described. In addition, the drawings of this application are diagrams schematically showing examples, and sometimes the scales of the respective parts are different from the actual situation in order to make the respective parts of these drawings recognizable, and the magnification ratios in the respective directions shown in these drawings are sometimes different, so there are cases where the respective drawings do not match. Of course, the respective elements of this manner are not limited to the specific examples indicated by the symbols. In the "Summary of the manners included in the present invention", the content in parentheses is a supplementary explanation of the immediately preceding term.

[0039] In addition, in this application, the numerical range "Min~Max" means not less than the minimum value Min and not more than the maximum value Max.

[0040] Manner 1

[0041] As exemplified by Figure 1 , 5 etc., a printing method according to one manner is a printing method for performing printing on the transfer medium M1. In order to perform an adhesive application step ST3 of applying an adhesive 111 onto a base ink 36b on an image IM1 formed by overlapping on the transfer medium M1, and a transfer step ST5 of transferring the image IM1 onto the transfer medium M2 by attaching the adhesive 111 to the transfer medium M2. This printing method includes the following steps.

[0042] (a1) An image forming step ST1 of forming the image IM1 on the transfer medium M1 by ejecting a colored ink 36a from a first inkjet head (for example, a colored ink head 31).

[0043] (a2) A substrate forming step ST2 of overlapping the base ink 36b on the image IM1 by relatively moving a second inkjet head (for example, the base ink head 32) in a first direction D1 with respect to the transfer medium M1 and ejecting the base ink 36b from the second inkjet head (32).

[0044] Here, as Figure 2 , 6 etc. illustrate, an area where the adhesive 111 is supplied to the transfer medium M1 at the same timing in the adhesive application step ST3 is set as a processing unit area A0. This processing unit area A0 includes a first area A1 and a second area A2 where the base ink 36b is overlapped on the image IM1 at a later time compared to the first area A1. In this printing method, in the substrate forming step ST2, the ejection amount of the base ink 36b per unit area for the second area A2 is made less than the ejection amount of the base ink 36b per unit area for the first area A1.

[0045] In the above-mentioned processing unit area A0, by making the ejection amount of the base ink for the second area A2 where the base ink 36b is overlapped on the image IM1 at a later time compared to the first area A1 less, the flow of the base ink 36b caused by the inclination of the transfer medium M1 in the adhesive application step ST3 can be suppressed. By suppressing the flow of the base ink 36b, bleeding of the transferred image (the transferred image IM1) caused by the downward sagging of the base ink 36b etc. can be suppressed. Therefore, the above method can provide a printing method capable of suppressing bleeding of the transferred image.

[0046] In the above method, various examples are considered.

[0047] The relative movement of the second inkjet head (32) in the first direction D1 with respect to the transfer medium M1 includes a case where the second inkjet head (32) moves in the first direction D1 under the condition that the transfer medium M1 does not move, a case where the transfer medium M1 moves in a direction opposite to the first direction D1 under the condition that the second inkjet head (32) does not move, and a case where both the transfer medium M1 and the second inkjet head (32) move along the first direction D1. In addition, the second inkjet head (32) may also relatively move in a second direction D2 intersecting the first direction D1 with respect to the transfer medium M1.

[0048] The first inkjet head (31) may relatively move with the second inkjet head (32) with respect to the transfer medium M1, or may relatively move with respect to the transfer medium M1 independently of the second inkjet head (32).

[0049] In the processing unit area A0, the following areas are included.

[0050] (Area b1) An area corresponding to the quantity of a single sheet of transfer medium when the transfer medium is a single sheet of paper (for example, refer to Figure 8 ).

[0051] (Area b2) An area corresponding to the quantity of one-time conveyance when the transfer medium, which is continuous paper subjected to side-shift printing, is intermittently conveyed (for example, refer to Figure 7 ).

[0052] (Area b3) An area corresponding to the conveyance quantity of one-time sub-scanning when sub-scanning is performed on the transfer medium subjected to serial printing (for example, refer to Figure 9 ).

[0053] (Area b4) An area corresponding to the quantity of a single sheet of the transfer medium after being cut when the transfer medium subjected to line printing is cut (for example, refer to Figure 10 ).

[0054] In addition, the printing on a single sheet of paper can be any one of side-shift type, serial type, and line type. The side-shift type is a printing method in which an inkjet head ejects ink while scanning in the main scanning direction and the sub-scanning direction intersecting with the main scanning direction with respect to the processing unit area of the transfer medium. The side-shift type for continuous paper is a printing method in which the inkjet head ejects ink while scanning in the conveying direction and the direction intersecting with the conveying direction with respect to the above-mentioned area b2 of the transfer medium in a conveying stop state, and the continuous paper is intermittently conveyed in the conveying direction in units corresponding to the above-mentioned area b2. The serial type is a printing method in which the inkjet head ejects ink while reciprocating in the main scanning direction and performs sub-scanning during the main scanning. The line type is a printing method in which ink is ejected from an inkjet head having a length greater than the width of the continuous paper onto the continuous paper being conveyed. The materials of the single sheet of paper and the continuous paper are not strictly limited to paper, and can also be resin, metal, etc.

[0055] In the substrate forming step ST2, the substrate ink 36b can be ejected from the second inkjet head (32) moving relatively in the first direction D1, or the substrate ink 36b can be ejected from the second inkjet head (32) moving relatively in the second direction D2 under the condition that the relative position in the first direction D1 remains unchanged.

[0056] The processing unit region A0 may also include a third region A3 where the base ink 36b overlaps the image IM1 later than the first region A1 and earlier than the second region A2. In this case, in the base forming step ST2, the ejection amount of the base ink 36b per unit area for the third region A3 may be more than that for the second region A2 and less than that for the first region A1 per unit area of the base ink 36b.

[0057] In the present application, "first", "second",... are terms used to recognize each structural element included in a plurality of structural elements having similarities, and do not refer to an order.

[0058] Of course, the above supplementary explanations also apply in the following manner.

[0059] Mode 2

[0060] Such as Figure 6 As exemplified, etc., the first region A1 may also include a portion where the base ink 36b first overlaps the image IM1 in the processing unit region A0. The second region A2 may also include a portion where the base ink 36b finally overlaps the image IM1 in the processing unit region A0.

[0061] In the processing unit region A0, by having a smaller ejection amount of the base ink on the side where the base ink 36b finally overlaps the image IM1 compared to the portion where the base ink 36b first overlaps the image IM1, it is possible to further suppress the flow of the base ink 36b caused by the inclination of the transfer medium M1 in the adhesive application step ST3. Therefore, the above mode can further suppress the bleeding of the transferred image.

[0062] Mode 3

[0063] Such as Figure 13 As exemplified, etc., at least one of the first region A1 and the second region A2 may include a first continuous region A11 that is connected as the image IM1 in one piece within the region, and a second continuous region A12 that is separated from the first continuous region A11 and is connected as the image IM1 in one piece within the region. Here, it is assumed that the area of the second continuous region A12 is larger than that of the first continuous region A11. In the present printing method, in the base forming step ST2, the ejection amount of the base ink 36b per unit area for the second continuous region A12 may be less than that for the first continuous region A11 per unit area of the base ink 36b.

[0064] The larger the continuous area is, the more likely it is that the base ink 36b will flow due to the inclination of the transfer medium M1 in the adhesive application step ST3. By reducing the ejection amount of the base ink for the relatively large second continuous area A12 in the first area A1 or the second area A2, the flow of the base ink 36b caused by the inclination of the transfer medium M1 in the adhesive application step ST3 can be further suppressed. Therefore, the above method can further suppress bleeding of the transferred image.

[0065] Method 4

[0066] As Figure 6 As exemplified by etc., in the present printing method, in the base formation step ST2, while the second inkjet head (32) is relatively moved with respect to the transfer medium M1 along a second direction D2 intersecting the first direction D1, the main scan of ejecting the base ink 36b can be performed, and by relatively moving the second inkjet head (32) with respect to the transfer medium M1 in the first direction D1 during the sub-scan during this main scan, the position where the base ink 36b is overlapped on the image IM1 is changed in the first direction D1. The second area A2 can also be an area where the base ink 36b is overlapped on the image IM1 in a main scan that is later than the main scan in which the base ink 36b is overlapped on the image IM1 located in the first area A1.

[0067] In printing that performs main scanning and sub-scanning in a manner such as image-side shifting or serial, regarding the difference in the ejection time of the base ink 36b, the sub-scanning direction is larger than the main scanning direction. Therefore, it is preferable to change the ejection amount of the base ink 36b in the sub-scanning direction compared to the main scanning direction. Therefore, the above method can appropriately suppress bleeding of the transferred image in the case of printing that performs main scanning and sub-scanning.

[0068] Here, the printing of Method 4 can be either single-cycle or multi-cycle (two or more cycles). The number of cycles refers to the number of main scans accompanied by the ejection of the base ink that are performed at the same position.

[0069] The above supplementary explanations also apply to the following methods.

[0070] Method 5

[0071] As Figure 9As exemplified, in this printing method, in the substrate forming step ST2, the main scanning of ejecting the substrate ink 36b may be performed while the second inkjet head (32) relatively moves in the first direction D1 with respect to the transfer medium M1. The second region A2 may also be a region where the substrate ink 36b overlaps the image IM1 in the main scanning later than in the first region A1 when the substrate ink 36b overlaps the image IM1 located in the first region A1.

[0072] Even within one main scan, there are differences in the ejection time of the substrate ink 36b, and thus the longer the distance of the main scan, the greater the difference in the ejection time of the substrate ink 36b. By reducing the ejection amount of the substrate ink for the second region A2 where the substrate ink 36b overlaps the image IM1 later than in the first region A1 within one main scan, the flow of the substrate ink 36b caused by the inclination of the transfer medium M1 in the adhesive application step ST3 can be suppressed. Therefore, the above method can appropriately suppress the bleeding of the transferred image caused by the difference in the ejection time of the substrate ink during the main scan.

[0073] Of course, after setting the first region A1 and the second region A2 to change the ejection amount of the substrate ink 36b by applying the sub-scanning direction to the first direction D1 as in Method 4, the main scanning direction can be applied to the first direction D1 to set the first region A1 and the second region A2 to change the ejection amount of the substrate ink 36b as in Method 5.

[0074] Method 6

[0075] As Figure 11 As exemplified, in this printing method, in the substrate forming step ST2, the tentative ejection amount PD of the substrate ink 36b may be determined regardless of the position in the first direction D1 in the processing unit region A0, and the ejection amount DT of the substrate ink 36b for the first region A1 and the second region A2 may be determined by multiplying the tentative ejection amount PD by the coefficient αi corresponding to the position in the first direction D1. In addition, the ejection amount DT of the substrate ink 36b is also referred to as the substrate ink ejection amount DT.

[0076] In the above case, it is possible to easily change the substrate ink ejection amount DT in the first region A1 and the second region A2. In addition, by accepting the input of the coefficient αi from the user, the substrate ink ejection amount DT can be adjusted according to the user's needs.

[0077] In addition, whether the image transferred onto the transfer medium becomes the intended image quality is affected not only by the amount and composition of the base ink, but also by the amount and composition of the colored ink for the image, the amount and composition of the adhesive attached to the base ink, and so on. Therefore, strictly speaking, the coefficient needs to be determined by considering a vast number of combinations that are envisaged, such as the amount and composition of the ink, the type of transfer medium, the amount and type of the adhesive, the type of the transfer medium to be transferred, etc. By accepting the input of the coefficient from the user, it is possible to avoid preparing coefficients for all the vast combinations that are envisaged, and thus contribute to the reduction of the memory.

[0078] Mode 7

[0079] The base ink 36b may also be an ink containing a component that blocks the transmission of light. In this case, since the color of the transfer medium M2 cannot be observed through the image portion, the image quality of the transferred image can be improved.

[0080] Here, among the inks containing a component that blocks the transmission of light, there are inks containing a component that diffuses light like white ink, inks containing a component that absorbs light like black ink, inks containing a component that diffuses light and a component that absorbs light like gray ink, and so on. This supplementary explanation also applies to the following modes.

[0081] Mode 8

[0082] As Figure 6 illustrated, printing is performed with main scanning and sub-scanning. As Figure 15 illustrated, the processing unit area A0 may also include a first ejection amount area AD1 where the ejection amount per unit area of the base ink 36b overlapped on the image IM1 is a first ejection amount (for example, 40% in Figure 15 ), and a second ejection amount area AD2 where the ejection amount per unit area of the base ink 36b overlapped on the image IM1 is a second ejection amount greater than the first ejection amount (for example, 80% in Figure 15 ). Here, the second ejection amount area AD2 is located at a position different from the first ejection amount area AD1 in the first direction D1. Let the number of cycles of the main scanning accompanied by the ejection of the base ink performed at the same position in the transfer medium M1 be the number of cycles NP. In this printing method, in the base formation step ST2, the number of cycles NP in the second ejection amount area AD2 may be made greater than the number of cycles NP in the first ejection amount area AD1.

[0083] Since the drying of the base ink 36b is promoted by increasing the number of cycles NP in the region where the ejection amount of the base ink is large, the flow of the base ink 36b caused by the inclination of the transfer medium M1 in the adhesive application step ST3 can be further suppressed. Therefore, the above-described method can further suppress the bleeding of the transferred image.

[0084] Method 9

[0085] In addition, as Figure 1 , 5 illustrated, the printing apparatus 1 according to one embodiment is a printing apparatus 1 that performs printing on the transfer medium M1 in order to execute an adhesive application step ST3 of applying an adhesive 111 onto the base ink 36b of the image IM1 formed by overlapping on the transfer medium M1, and a transfer step ST5 of transferring the image IM1 onto the transfer medium M2 by attaching the adhesive 111 to the transfer medium M2. As Figures 2 to 4 illustrated, the printing apparatus 1 includes a first inkjet head (31) that ejects a colored ink 36a, a second inkjet head (32) that ejects the base ink 36b, a drive unit 50, and a control unit 10. The drive unit 50 relatively moves the second inkjet head (32) in a first direction D1 with respect to the transfer medium M1. The control unit 10 controls the ejection of the colored ink 36a from the first inkjet head (31), the ejection of the base ink 36b from the second inkjet head (32), and the drive unit 50. As Figure 5 illustrated, the control unit 10 performs control such that the image IM1 is formed on the transfer medium M1 by the colored ink 36a ejected from the first inkjet head (31), and the base ink 36b ejected from the second inkjet head (32) is overlapped on the image IM1.

[0086] Here, a region where the adhesive 111 is supplied to the transfer medium M1 at the same timing in the adhesive application step ST3 is set as a processing unit region A0. The processing unit region A0 includes a first region A1 and a second region A2 where the base ink 36b is overlapped on the image IM1 at a later time than the first region A1. The control unit 10 makes the ejection amount per unit area of the base ink 36b for the second region A2 less than the ejection amount per unit area of the base ink 36b for the first region A1.

[0087] The above-described method can provide a printing apparatus that can suppress the bleeding of a transferred image.

[0088] Moreover, the above-described method can be applied to a printing system including the above-described printing apparatus, a control method for the above-described printing apparatus, a control method for the printing system described above, a control program for the above-described printing apparatus, a control program for the printing system described above, a computer-readable recording medium recording any of the control programs described above, and the like. In addition, the above-described printing apparatus may also be composed of a plurality of dispersed parts.

[0089] (2) Specific examples of the printing apparatus:

[0090] Figure 1 Schematically illustrated is the structure of a printing system that forms an image IM1 on a transfer medium M1 and transfers the image IM1 onto a medium M2 to be transferred. Figure 1 The illustrated printing system includes a printing apparatus 1, an adhesive supply apparatus 100, and a thermal transfer apparatus 200.

[0091] Although the printing apparatus 1 may also be a single printer 2, it may also be composed of a printer 2 and a host apparatus HO1 as Figure 1 illustrated. Figure 1 The illustrated host apparatus HO1 can generate image data DA1 corresponding to the image IM1 to be transferred and can transmit the image data DA1 to the printer 2. Hereinafter, the image IM1 to be transferred is also referred to as the transfer image IM1. The printer 2 includes a printing unit 20 that ejects ink onto the transfer medium M1 to form an image IM1 corresponding to the image data DA1 on the transfer medium M1. The adhesive supply apparatus 100 includes an adhesive tank 110 that causes the adhesive 111 to adhere to the ink on the transfer medium M1 and a heating unit 120 that heats the transfer medium M1 after the adhesive is supplied. The thermal transfer apparatus 200 transfers the image IM1 from the transfer medium M1 onto the medium M2 to be transferred.

[0092] In the transfer medium M1, a transfer film or the like that can transfer an image by the DTF (Direct to Film) method can be used. In such a transfer film, a resin film such as a PET (polyethylene terephthalate) film can be preferably used. Of course, the material of the transfer medium M1 may include paper, metal, etc. in addition to resin, and the transfer medium M1 may also be a metal film or the like. In the adhesive 111, a powdery adhesive such as a powdery hot-melt adhesive can be used. The hot-melt adhesive is a thermoplastic resin powder, which melts when heated above the melting point and solidifies when cooled. In the hot-melt adhesive, an adhesive containing one or more thermoplastic resins selected from polyurethane resins, polyolefin resins, polyamide resins, polyester resins, etc. can be used. In the medium to be transferred M2, fabrics such as woven or knitted fabrics, non-woven fabrics, etc. can be used, and processed fabrics such as T-shirts can also be used.

[0093] Although it will be described in detail later, in the printing apparatus 1, an image forming step ST1 and a substrate forming step ST2 are carried out. In the adhesive supply apparatus 100, an adhesive supply step ST3 and a heating step ST4 are carried out. In the thermal transfer apparatus 200, a transfer step ST5 is carried out.

[0094] Figure 2 A top view schematically illustrating the structure of the printer 2 having the inkjet head 30 is shown. In addition, Figure 2 The illustrated processing unit area A0 is a rectangle with a length of L0 and a width of W0. Figure 3 A bottom view schematically illustrating the nozzle surface 30a of the inkjet head 30 is shown. Figure 4 A block diagram schematically illustrating the structure of the printing apparatus 1 is shown. Figure 5 A printing method for the medium to be transferred M2 is schematically illustrated. Figure 6 A regional division of the processing unit area A0 is schematically illustrated.

[0095] The printer 2 is an inkjet printer that ejects liquid ink droplets 37. The printer 2 includes a control unit 10, a printing unit 20, a RAM (Random Access Memory) 21 as a semiconductor memory, a communication I / F (interface) 22, a storage unit 23, an operation panel 24, and the like. The control unit 10, the RAM 21, the communication I / F 22, the storage unit 23, and the operation panel 24 are connected to a bus and are configured to be able to input and output information to each other. The printing unit 20 includes an inkjet head 30 and a drive unit 50.

[0096] The control unit 10 includes a CPU (Central Processing Unit) 11 as a processor, a color conversion unit 12, a halftone processing unit 13, a rasterization processing unit 14, a drive signal transmission unit 15, and the like. The control unit 10 can be constituted by an SoC (System on a Chip) or the like. Based on the image data DA1 obtained from either the host device HO1 or an external memory (not shown), the control unit 10 controls the inkjet head 30 and the drive unit 50 to form an image IM1 of the colored ink 36a and a layer of the base ink 36b on the transfer medium M1. In the image data DA1, for example, RGB data having integer values of, for example, 2 8 gray levels for each pixel can be applied.

[0097] The CPU 11 is a device that centrally implements information processing and control in the printer 2.

[0098] The color conversion unit 12, for example, has a color conversion LUT (Look-Up Table) that defines the correspondence between the gray levels of R, G, and B and the gray levels of C (cyan), M (magenta), Y (yellow), K (black), and W (white). In the color conversion LUT, the gray level of W is, for example, the value for using the base ink 36b when using at least one of the colored inks 36a of C, M, Y, and K. If an example is given, when the gray levels of C, M, Y, and K are 0 indicating that the colored ink is not used, the gray level of W is 0 indicating that the base ink is not used, and in the remaining cases, the gray level of W is 128 indicating that 50% of the base ink is used. Thus, the base ink 36b is overlapped at the position of the image IM1. Of course, the ejection amount of the base ink 36b overlapped on the image IM1 can be less than 50% or more than 50% within the range of the transfer image IM1 that can obtain a relatively good image quality. The color conversion unit 12 refers to the color conversion LUT and converts the RGB data into ink amount data having integer values of, for example, 2 8 gray levels for each pixel for C, M, Y, and K. The ink amount data represents the usage amounts of the inks 36 of C, M, Y, K, and W in units of pixels. Additionally, in Figure 4 the shown ink 36, there are included the colored inks 36a of C, M, Y, and K and the base ink 36b. Further, when the resolution of the RGB data is different from the printing resolution, the color conversion unit 12 first converts the resolution of the RGB data to the printing resolution or converts the resolution of the ink amount data to the printing resolution.

[0099] The halftone processing unit 13 performs halftone processing on the ink amount data by any method such as dithering or error diffusion, thereby generating dot data with the number of gray levels reduced to, for example, 2 or 4. The dot data is generated separately for C, M, Y, K, and W. The dot data represents the formation state of the dots of the ink 36 in units of pixels.

[0100] The rasterization processing unit 14 performs rasterization processing to arrange and exchange the dot data in the order in which the dots are formed by the driving unit 50, thereby generating raster data.

[0101] The drive signal transmission unit 15 generates a drive signal SG1 corresponding to the voltage signal applied to the drive element 42 of the inkjet head 30 from the raster data, and outputs this signal to the drive circuit 41 of the inkjet head 30.

[0102] The RAM 21 stores the image data DA1, etc. received from the host device HO1, etc. The communication I / F 22 inputs and outputs information to and from the host device HO1, etc. Examples of the host device HO1 include computers such as personal computers and tablet terminals, and mobile phones such as smartphones. The storage unit 23 can be a non-volatile semiconductor memory such as a flash memory, or a magnetic storage device such as a hard disk. The operation panel 24 includes an output unit 25 such as a liquid crystal panel for displaying information, and an input unit 26 such as a touch panel for accepting operations on the display screen.

[0103] The drive circuit 41 applies a voltage signal to the drive element 42 according to the drive signal SG1 input from the drive signal transmission unit 15. The drive element 42 can be a piezoelectric element that applies pressure to the ink 36 in the pressure chamber communicating with the nozzle 34, or a drive element that generates bubbles in the pressure chamber by heat to eject the ink droplets 37 from the nozzle 34. In the pressure chamber of the inkjet head 30, the ink 36 is supplied from the ink cartridge 35. The ink 36 in the pressure chamber is ejected as ink droplets 37 from the nozzle 34 toward the transfer medium M1 through the drive element 42. When the ink droplets 37 fall onto the transfer medium M1, dots are formed on the transfer medium M1. When dots of the colored ink 36a are formed on the transfer medium M1, the image IM1 represented by the pattern of the dots is formed on the transfer medium M1.

[0104] Figure 3The inkjet head 30 shown includes a color ink head 31 that ejects color ink 36a, and a base ink head 32 that ejects base ink 36b. The color ink head 31 is an example of a first inkjet head, and the base ink head 32 is an example of a second inkjet head. The color ink 36a is an ink that contains a color material such as a pigment as a dispersed substance or solute in a liquid (such as water) serving as a dispersion medium or solvent. In the color ink 36a, for example, there are colored inks containing C, M, and Y, and an ink of K as achromatic color. The color ink head 31 includes a C ink head 31C that ejects C ink, an M ink head 31M that ejects M ink, a Y ink head 31Y that ejects Y ink, and a K ink head 31K that ejects K ink. The base ink 36b is an ink containing a component that blocks the transmission of light, for example, a W ink containing a component that diffuses light. The W ink is, for example, an ink that contains a white pigment such as titanium oxide or zinc oxide as a dispersed substance in a liquid such as water serving as a dispersion medium. By blocking the transmission of light with the base ink 36b, the color of the transfer medium M2 that becomes the background of the image IM1 does not affect the color of the image IM1, and thus a transfer medium M2 with a relatively good image quality can be obtained for the image IM1. Each ink head (31C, 31M, 31Y, 31K, 32) has a nozzle row in which a plurality of nozzles 34 are arranged in a nozzle arrangement direction that intersects the second direction D2 as the scanning direction, for example, the first direction D1. The plurality of nozzles 34 of each ink head may also be arranged in a staggered manner in the nozzle arrangement direction, or in other words, arranged in two rows in the nozzle arrangement direction. The nozzle arrangement direction may deviate from the first direction D1 within a range less than 90°. Each nozzle 34 of the color ink head 31 ejects the color ink 36a as ink droplets 37, and each nozzle 34 of the base ink head 32 ejects the base ink 36b as ink droplets 37. Figures 2 to 4 The inkjet head 30 shown is mounted on the carriage 33. When the printer 2 performs side-shift printing, the carriage 33 can move along the second direction D2 as the main scanning direction and the first direction D1 as the sub-scanning direction.

[0105] As a side-shift driving unit 50 includes a main scanning driving unit 51, a sub-scanning driving unit 52, and a conveying unit 55. Figure 2 The main scanning driving unit 51 shown performs main scanning in which while moving the inkjet head 30 along the second direction D2 as the main scanning direction, ink 36 is ejected from the inkjet head 30 in at least one of the forward direction D11 and the return direction D12. If we focus on the base ink head 32, it can be said that the main scanning driving unit 51 performs main scanning in which the base ink head 32 ejects the base ink 36b while relatively moving along the second direction D2 with respect to the transfer medium M1. Figure 2The sub-scanning drive unit 52 shown performs sub-scanning that moves the inkjet head 30 in a first direction D1, which is the sub-scanning direction, during main scanning. That is, during sub-scanning, the inkjet head 30 moves intermittently in the first direction D1. If we focus on the base ink head 32, it can be said that the sub-scanning drive unit 52 relatively moves the base ink head 32 in the first direction D1 with respect to the transfer medium M1 during sub-scanning within the main scanning period. Figure 2 The transport unit 55 shown transports the transfer medium M1, which is a continuous sheet, in a first direction D1, which is the transport direction, during the printing period of the processing unit area A0. That is, during non-printing, the transfer medium M1 moves intermittently in the first direction D1. Figure 2 , 4 The transport unit 55 shown transports the transfer medium M1 in the first direction D1 along the transport path 59. The platen 58 is located below the transport path 59 and supports the transfer medium M1 by contacting the transfer medium M1 located on the transport path 59. The inkjet head 30 controlled by the control unit 10 ejects ink droplets 37 toward the transfer medium M1 supported on the platen 58, thereby attaching the ink 36 to the transfer medium M1.

[0106] The control unit 10 controls the ejection of the colored ink 36a from the colored ink head 31, the ejection of the base ink 36b from the base ink head 32, and the drive unit 50.

[0107] In addition, as long as the base ink 36b can be overlapped on the image IM1 formed by the colored ink 36a, various configurations can be considered for the base ink head 32. For example, the base ink head 32 can also be located at a position facing the return direction D11 from the Figure 3 shown C ink head 31C, and can also be located at a position facing a direction opposite to the sub-scanning direction from the colored ink head 31.

[0108] Next, with reference to Figure 5 , 6 and so on, the printing method for the transfer medium M2 will be described. Figure 5 The printing method shown includes the following steps.

[0109] (c1) An image forming step ST1 of forming an image IM1 on the transfer medium M1 by ejecting the colored ink 36a from the colored ink head 31.

[0110] (c2) A base forming step ST2 of overlapping the base ink 36b on the image IM1 by relatively moving the base ink head 32 in the first direction D1 with respect to the transfer medium M1 and ejecting the base ink 36b from the base ink head 32.

[0111] (c3) Adhesive application step ST3 of applying an adhesive 111 onto a base ink 36b that is overlapped on an image IM1 formed on a transfer medium M1.

[0112] (c4) Heating step ST4 of heating the transfer medium M1 to which the adhesive 111 has been applied.

[0113] (c5) Transfer step ST5 of transferring the image IM1 onto a transfer medium M2 by causing the adhesive 111 to adhere to the transfer medium M2.

[0114] For example, as Figure 6 shown, a situation is envisioned where inks 36 are ejected from an inkjet head 30 in units of belts B1 to B6 with respect to a processing unit area A0. For example, in the case where a second main scan for ejecting the base ink 36b is performed after a first main scan where the colored ink 36a has been ejected for each belt, the image forming step ST1 is performed using the first main scan, and the base forming step ST2 is performed using the second main scan. In the case where the first main scan is a main scan in the forward direction D11, the second main scan can be a main scan in the return direction D12 like duplex printing, or can be a main scan in the forward direction D11 like simplex printing. As long as the base ink 36b overlaps the image IM1 formed by the colored ink 36a without mixing, the image forming step ST1 and the base forming step ST2 can also be performed using a single main scan in the forward direction D11 by the Figure 3 shown inkjet head 30.

[0115] For each belt, the image IM1 can be formed in a single cycle manner, the base ink 36b can be overlapped on the image IM1 in a single cycle manner, the image IM1 can be formed in a multi-cycle manner, and the base ink 36b can also be overlapped on the image IM1 in a multi-cycle manner.

[0116] In Figure 1 the shown example, the transfer medium M1 on which the base ink 36b is overlapped on the image IM1 is intermittently conveyed from the printer 2 to the adhesive application device 100 and obliquely enters the adhesive tank 110. When the powdery adhesive 111 enters the adhesive tank 110, the adhesive 111 adheres to the undried base ink 36b. In Figure 5 , a state is shown where the image IM1, the base ink 36b, and the powdery adhesive 111 are sequentially laminated on the transfer medium M1 in the adhesive application step ST3. The adhesive application step ST3 is performed in this way. In Figure 1In the illustrated example, the transfer medium M1 to which the thermoplastic adhesive 111 is applied is intermittently conveyed from the adhesive tank 110 to the heating unit 120. During this period, the excess adhesive 111 is shaken off by tilting the transfer medium M1 again or the like. The heating unit 120 heats the transfer medium M1 to which the adhesive 111 is applied. When the transfer medium M1 is heated to a temperature above the melting temperature of the adhesive 111, the adhesive 111 melts. In Figure 5 , a state is shown in which the image IM1, the dried base ink 36b, and the melted adhesive 111 are sequentially laminated on the transfer medium M1 in the heating step ST4. When the thermal transfer device 200 can heat the transfer medium M1, the heating unit 120 may also perform preheating on the transfer medium M1 to a temperature lower than the melting temperature of the adhesive 111. The heating step ST4 is carried out in this way. In Figure 1 the illustrated example, the heated transfer medium M1 is intermittently discharged from the heating unit 120. The discharged transfer medium M1 is cut as needed, overlapped on the transfer medium M2 with the surface to which the adhesive 111 is applied facing the transfer medium M2, and fed into the thermal transfer device 200.

[0117] The thermal transfer device 200 presses the transfer medium M1 and the transfer medium M2 in a state where the adhesive 111 applied to the transfer medium M1 is in contact with the transfer medium M2. When the thermal transfer device 200 has a heating mechanism, the thermal transfer device 200 heats the transfer medium M1 and the transfer medium M2 to a temperature above the melting temperature of the adhesive 111. In Figure 5 , a state is shown in which the melted adhesive 111, the dried base ink 36b, the image IM1, and the transfer medium M1 are sequentially laminated on the transfer medium M2. By pressing the transfer medium M1 and the transfer medium M2, the image IM1 is attached to the transfer medium M2 via the base ink 36b and the adhesive 111. The transfer step ST5 of transferring the image IM1 to the transfer medium M2 is carried out in this way. When the transfer medium M1 is peeled off from the transfer medium M2, the image IM1 remains on the transfer medium M2, and thus a transfer medium M2 having the image IM1 transferred thereon as shown in Figure 1 can be obtained. Since there is a layer of the base ink 36b between the transferred image IM1 and the transfer medium M2, it is possible to suppress the color of the transfer medium M2 from affecting the image IM1, and thus the image quality of the image IM1 is relatively good.

[0118] Although the above transfer medium M1 is continuous paper, the transfer medium M1 can also be a single sheet of paper. In this case, the user can also place the printed single sheet of paper into the adhesive tank 110 to cause the powdery adhesive 111 to adhere to the base ink 36b. In this operation, the transfer medium M1 is inclined.

[0119] When the base ink 36b is sprayed onto the image IM1 on the transfer medium M1, it gradually dries. In the processing unit area A0 where the adhesive 111 is supplied at the same timing in the adhesive supply process ST3 with respect to the transfer medium M1, the later the spraying of the base ink 36b becomes, the smaller the degree of drying of the base ink 36b. Therefore, when the transfer medium M1 is inclined to supply the adhesive 111 or the like, the base ink 36b with a smaller degree of drying sometimes flows downward. If the base ink 36b flows downward, the transferred image IM1 will bleed, resulting in a reduction in the image quality of the transferred image IM1.

[0120] However, if the implementation of the adhesive supply process ST3 is delayed in order to increase the drying time of the base ink 36b, the productivity after the adhesive supply process ST3 will be reduced.

[0121] The printing apparatus 1 of this specific example solves the above problems by making the ejection amount of the base ink 36b per unit area in the second area A2 where the base ink 36b is overlapped on the image IM1 later in the above processing unit area A0 smaller.

[0122] First, refer to Figure 6 to illustrate the area division of the processing unit area A0 and examples of the ejection amount of the base ink per unit area of each area.

[0123] In the processing unit area A0, the above areas b1 to b4 can be cited. Figure 6An example is shown in which main scanning and sub-scanning are performed in units of belts B1 to B6 with respect to the area b1 of a single sheet of paper or the area b2 during side-shift printing. The control unit 10 controls the main scanning to be performed such that the inkjet head 30 ejects the ink 36 while relatively moving with respect to the transfer medium M1 along the second direction D2. The control unit 10 performs the following control: by relatively moving the colored ink head 31 with respect to the transfer medium M1 in the first direction D1 during the sub-scanning within the main scanning, the position in the first direction D1 where the image IM1 is formed on the transfer medium M1 is changed. Further, the control unit 10 performs the following control: by relatively moving the base ink head 32 with respect to the transfer medium M1 in the first direction D1 during the sub-scanning, the position in the first direction D1 where the base ink 36b is overlapped on the image IM1 is changed. The image IM1 is formed on the transfer medium M1 in units of belts B1 to B6 in the order of the first direction D1, and the base ink 36b is overlapped on the image IM1 in units of belts B1 to B6 in the order of the first direction D1. Figure 6 The shown processing unit area A0 includes a first area A1 and a second area A2 where the base ink 36b is overlapped on the image IM1 at a later time compared to the first area A1. The second area A2 is an area where the base ink 36b is overlapped on the image IM1 in a main scanning that is later than the main scanning in which the base ink 36b is overlapped on the image IM1 located in the first area A1. In Figure 6 it, various examples C1 to C4 of dividing the belts B1 to B6 into areas are shown.

[0124] In Example C1, belts B1 and B2 are assigned to the first area A1, belts B3 and B4 are assigned to the third area A3, and belts B5 and B6 are assigned to the second area A2. The first area A1 includes belt B1 that first overlays the base ink 36b on the image IM1 in the processing unit area A0. The third area A3 overlays the base ink 36b on the image IM1 at a time later than the first area A1 and earlier than the second area A2. The second area A2 includes belt B6 that last overlays the base ink 36b on the image IM1 in the processing unit area A0. The control unit 10 controls the ejection amount of the base ink 36b per unit area for the first area A1 to the ejection amount DT1, controls the ejection amount of the base ink 36b per unit area for the third area A3 to the ejection amount DT3, and controls the ejection amount of the base ink 36b per unit area for the second area A2 to the ejection amount DT2. The ejection amount DT3 is less than the ejection amount DT1, and the ejection amount DT2 is less than the ejection amount DT3. The ejection amounts DT2 and DT3 only need to be set within a range where the influence on the image quality of the transfer image IM1 caused by the change in the ejection amount DT of the base ink is small.

[0125] In addition, the ejection amount (denoted as DT) of the base ink 36b per unit area refers to the ratio (including percentage) of the number of dots formed by the ink droplets 37 to a predetermined number of pixels, and in the case of forming dots of different sizes, it refers to the ratio when converted to the largest dot (e.g., large dot). A pixel is the smallest element that constitutes an image capable of independently allocating colors. For example, when forming Nd large dots for 100 pixels, the ejection amount DT becomes Nd%.

[0126] In the processing unit area A0, by making the ejection amount DT2 for the second area A2, which overlays the base ink 36b on the image IM1 at a time later than the first area A1, smaller, the flow of the base ink 36b caused by the inclination of the transfer medium M1 in the adhesive application step ST3 can be suppressed. By suppressing the flow of the base ink 36b, bleeding of the transfer image IM1 caused by the downward sagging of the base ink 36b, etc., can be suppressed, and thus the image quality of the transfer image IM1 is improved.

[0127] Furthermore, by placing the third area A3 with an ejection amount DT3 that is less than the ejection amount DT1 and more than the ejection amount DT2 between the first area A1 and the second area A2, the change in the ejection amount DT of the base ink caused by the area change is reduced. As a result, the influence on the image quality of the transfer image IM1 caused by the change in the ejection amount DT of the base ink becomes smaller, and thus the image quality of the transfer image IM1 is improved.

[0128] In Example C2, the third area A3 is not present in the processing unit area A0, and belts B1 to B4 are assigned to the first area A1, and belts B5 and B6 are assigned to the second area A2. Even without the third area A3, by making the ejection amount DT2 for the second area A2 small, it is possible to suppress the flow of the base ink 36b caused by the inclination of the transfer medium M1 in the adhesive application step ST3, and thus it is possible to suppress the bleeding of the transfer image IM1.

[0129] In Example C3, only the last belt B6 is assigned to the second area A2, and belts B1 to B5 are assigned to the first area A1. Inside the processing unit area A0, the base ink 36b is most likely to flow in the last belt B6. Therefore, in Example C3 as well, it is possible to effectively suppress the flow of the base ink 36b caused by the inclination of the transfer medium M1 in the adhesive application step ST3, and thus it is possible to effectively suppress the bleeding of the transfer image IM1.

[0130] In Example C4, the base ink ejection amounts DT for the respective belts B1 to B6 are set such that the base ink ejection amount DT gradually decreases from belt B1 to belt B6. In this case, for example, belts B1 to B5 can be applied to the first area A1, and belt B6 can be applied to the second area A2. In Example C4, the influence on the image quality of the transfer image IM1 due to the change in the base ink ejection amount DT is small, and thus the image quality of the transfer image IM1 is improved.

[0131] Figure 7 Schematically illustrated is the side-shift intermittent conveyance with respect to the continuous paper M11 as the transfer medium M1.

[0132] The side-shift with respect to the continuous paper M11 is a printing method in which ink 36 is ejected from the inkjet head 30 while the inkjet head 30 scans horizontally and vertically with respect to the processing unit area A0 of the continuous paper M11 in a conveyance stop state, and the continuous paper M11 is conveyed in the conveyance direction by a conveyance amount L1 corresponding to each processing unit area A0. In Figure 6 the example shown, the second direction D2 is the main scanning direction, and the first direction D1 is the sub-scanning direction and also the conveyance direction. With respect to the continuous paper M11, the adhesive 111 is supplied at the same timing in the adhesive application step ST3 in units of the conveyance amount L1. Therefore, the processing unit area A0 becomes the area b2 corresponding to one conveyance amount L1 in the case where the continuous paper M11 is intermittently conveyed.

[0133] Figure 7The state SA1 shown is a state in which the conveyance of the continuous paper M11 as the transfer medium M1 stops and printing is being performed in the processing unit area A01 as the processing unit area A0. When the image IM1 is formed in the processing unit area A01 and the base ink 36b is overlapped on the image IM1, the conveyance unit 55 conveys the continuous paper M11 in the first direction D1 with a predetermined conveyance amount L1. The conveyance amount L1 is the distance obtained by adding the length of the processing unit area A0 in the first direction D1 and a predetermined margin. The next state SA2 is a state in which the conveyance of the continuous paper M11 stops and printing is being performed in the processing unit area A02 as the processing unit area A0. When the image IM1 is formed in the processing unit area A02 and the base ink 36b is overlapped on the image IM1, the conveyance unit 55 conveys the continuous paper M11 in the first direction D1 with the conveyance amount L1. The next state SA3 is a state in which the conveyance of the continuous paper M11 stops and printing is being performed in the processing unit area A03 as the processing unit area A0.

[0134] In the above manner, the printer 2 forms the image IM1 for the processing unit area A0 of the continuous paper M11 in the conveyance stop state, overlaps the base ink 36b on the image IM1, and intermittently conveys the continuous paper M11 in the first direction D1 with the conveyance amount L1.

[0135] Figure 8 The processing unit area A0 in the single sheet of paper M12 is schematically illustrated. Although the printing on the single sheet of paper M12 can be any one of the lateral shift type, serial type, and line type, Figure 8 An example of performing lateral shift type or serial type printing on the single sheet of paper M12 is shown.

[0136] In the case where the transfer medium M1 is the single sheet of paper M12, the adhesive 111 is supplied at the same timing in the adhesive application step ST3 for one single sheet of paper M12. Therefore, the processing unit area A0 becomes the area b1 corresponding to the amount of one single sheet of paper.

[0137] In addition, in the printing that performs main scanning and sub-scanning, regarding the difference in the spraying time of the base ink 36b, the sub-scanning direction is larger than the main scanning direction. Therefore, by changing the ejection amount of the base ink 36b in the sub-scanning direction compared to the main scanning direction, bleeding of the transferred image IM1 can be appropriately suppressed.

[0138] Figure 9 The area division of the processing unit area A0 corresponding to the conveyance amount of one sub-scanning is schematically illustrated.

[0139] In the case of performing serial printing, the transfer medium M1 is conveyed by an amount L2, which is the conveyance amount for one sub-scan in the conveyance direction. Even within one main scan, there are differences in the ejection timing of the base ink 36b, and thus, the longer the distance of the main scan, the greater the differences in the ejection timing of the base ink 36b become. Therefore, it is considered that in the transfer medium M1, a region corresponding to one conveyance amount L2 is set as the processing unit region A0, and the case where the processing unit region A0 is divided in the main scan direction is considered. In Figure 9 the illustrated example, an example where the main scan direction is the first direction D1 and the sub-scan direction is the second direction D2. The conveyance direction of the transfer medium M1 is the direction opposite to the second direction D2. The drive unit 50 for realizing serial printing only needs to include a main scan drive unit 51 and a conveyance unit 55. The main scan drive unit 51 performs a main scan of ejecting the ink 36 while moving the inkjet head 30 along the first direction D1, and the conveyance unit 55 performs a sub-scan of conveying the transfer medium M1 in the direction opposite to the second direction D2. In other words, the main scan drive unit 51 changes the position in the first direction D1 where the base ink 36b is overlapped on the image IM1 by performing a main scan of ejecting the base ink 36b while relatively moving the base ink head 32 along the first direction D1 with respect to the transfer medium M1. The conveyance unit 55 relatively moves the base ink head 32 with respect to the transfer medium M1 in the direction opposite to the second direction D2 during the sub-scan in the main scan.

[0140] The serial type for the continuous paper M11 is a printing method in which the inkjet head 30 scans along the first direction D1 for the processing unit region A0 of the continuous paper M11 that is in a conveyance stop state, the ink 36 is ejected from the inkjet head 30, and the continuous paper M11 is conveyed by the conveyance amount L2 in the conveyance direction. Therefore, the processing unit region A0 becomes the region b3 corresponding to the conveyance amount L2 for one sub-scan. The second region A2 divided in the main scan direction is the region where the base ink 36b is overlapped on the image IM1 at a later time than the first region A1 in the main scan of overlapping the base ink 36b on the image IM1 located in the first region A1.

[0141] In order to reduce the waste of the transfer medium M1, it is often the case that a plurality of separated images are arranged on the transfer medium M1 in the main scanning direction. Therefore, there is a time difference in the ejection of the base ink 36b overlapping on the image during the same main scan. In such a case, by making the ejection amount of the base ink for the second region A2 where the base ink 36b overlaps on the image IM1 later than the first region A1 where the base ink 36b first overlaps on the image IM1 less within one main scan, it is possible to suppress the flow of the base ink 36b caused by the inclination of the transfer medium M1 in the adhesive application step ST3.

[0142] In Figure 9 various examples C1 to C4 of dividing the processing unit region A0 corresponding to the conveyance amount L2 per one sub-scan are shown. In example C1, the main scan start region located at the left part of Figure 9 is assigned to the first region A1, the main scan end region located at the right part of Figure 9 is assigned to the second region A2, and the region between the first region A1 and the second region A2 is assigned to the third region A3. The ejection amount DT3 for the third region A3 is less than the ejection amount DT1 for the first region A1, and the ejection amount DT2 for the second region A2 is less than the ejection amount DT3 for the third region A3. In example C2, there is no third region A3 in the processing unit region A0, the main scan end region is assigned to the second region A2, and the remaining part is assigned to the first region A1. In example C3, compared with example C2, the second region A2 is narrower and the first region A1 is wider. Since the main scan end part at the right end of Figure 9 is the part where the base ink 36b is most likely to flow within the processing unit region A0, in example C3, it is also possible to effectively suppress the flow of the base ink 36b caused by the inclination of the transfer medium M1 in the adhesive application step ST3. In example C4, the ejection amount DT of the base ink for the processing unit region A0 is set such that the ejection amount DT of the base ink gradually decreases from the main scan start part to the main scan end part. In example C4, the influence on the image quality of the transferred image IM1 due to the change in the ejection amount DT of the base ink is small.

[0143] Of course, it is also possible to divide the regions to change the ejection amount DT of the base ink by applying the sub-scanning direction to the first direction D1 as shown in Figure 6 , and then, as shown in Figure 9 , divide the regions to change the ejection amount DT of the base ink by applying the main scanning direction to the first direction D1.

[0144] Figure 10Schematically illustrated is a processing unit area A0 in the case where a continuous sheet M11 is cut at a cutting position P1. Figure 10 The illustrated printer 2 is a printer that performs line printing on the continuous sheet M11, but the printing on the cut continuous sheet M11 may also be a side shift type or a serial type. In the case of performing line printing, the continuous sheet M11 continuously moves in the Figure 10 transport direction that is the right direction in []. The first direction D1 in which the inkjet head 30 relatively moves with respect to the continuous sheet M11 is a direction opposite to the transport direction.

[0145] In the case where the continuous sheet M11 after forming the image IM1 with the base ink 36b overlapped thereon is cut, for one transfer medium M13 obtained from the continuous sheet M11, the adhesive 111 is supplied at the same timing in the adhesive application step ST3. Therefore, the processing unit area A0 becomes an area b4 corresponding to the amount of one cut transfer medium. In the processing unit area A0, the second area A2 is located closer to the printer 2 than the first area A1. In the second area A2, the base ink 36b is overlapped on the image IM1 at a time later than in the first area A1.

[0146] (3) Specific example of the processing of the printing apparatus:

[0147] Figure 11 Schematically illustrated is a printing control process for implementing control to form an image IM1 on the transfer medium M1 and overlap the base ink 36b on the image IM1. In Figure 11 , a structural example of a coefficient table T1 for calculating the ejection amount DT of the base ink is also shown. The printer 2 may also hold the coefficient table T1 and store the coefficient table T1 in the storage unit 23. Figure 11 The illustrated printing control process targets side shift type or serial type printing. When a printing instruction for the transfer medium M1 is received from the host device HO1 or the operation panel 24, Figure 4 the illustrated control unit 10 starts the printing control process.

[0148] When starting the printing control process, the control unit 10 acquires image data DA1 representing the transfer medium M1 from the host device HO1 or the like (step S102). Hereinafter, there are cases where the description of "step" is omitted and the symbol of the step is shown in parentheses.

[0149] After acquiring the image data DA1, the control unit 10 sets a target pixel for color conversion from among the multiple pixels that make up the image data DA1 (S104). Next, the control unit 10 converts the grayscale value of the target pixel into a value representing the usage amounts of the colored ink 36a and the base ink 36b (S106). When the image data DA1 is RGB data and the ink amount data is CMYKW data representing the usage amounts of the inks 36 of C, M, Y, K, and W, the control unit 10 refers to the color conversion LUT and converts each pixel value of R, G, B into each pixel value of C, M, Y, K, W. In the color conversion LUT, the grayscale value of W is set to the value for using the base ink 36b when using at least one of the colored inks 36a of C, M, Y, K. Thus, the base ink 36b is overlapped at the position of the image IM1. The grayscale value of W after color conversion in the target pixel represents the tentative ejection amount PD of the base ink 36b determined regardless of the position in the first direction D1 in the processing unit area A0. Since the tentative ejection amount PD is represented as 0 to 100%, if the grayscale value of W is 0 to 255, the grayscale value of W is made to represent the tentative ejection amount PD by making the grayscale values 0 to 255 correspond to the tentative ejection amounts 0 to 100%.

[0150] Next, the control unit 10 refers to the coefficient table T1 and calculates the base ink ejection amount DT by multiplying the coefficient αi corresponding to the area Ai included in the processing unit area A0 by the tentative ejection amount PD of the base ink 36b (S108). Here, the area Ai is any one of the first area A1, the second area A2, and the third area A3. The coefficient αi is a coefficient corresponding to the position in the first direction D1. The process of S108 can also be said to be a process of correcting the base ink data such as the W data in the CMYKW data and the ink amount data.

[0151] The coefficient table T1 has a coefficient α1 associated with the first area A1, a coefficient α2 associated with the second area A2, and a coefficient α3 associated with the third area A3. In Figure 11 it shows the case where α1 = 1.2, α2 = 0.8, and α3 = 1.0. In this case, the ejection amount DT1 for the first area A1 becomes 1.2 × PD, the ejection amount DT2 for the second area A2 becomes 0.8 × PD, and the ejection amount DT3 for the third area A3 becomes 1.0 × PD. Therefore, the ejection amount DT3 for the third area A3 is less than the ejection amount DT1 for the first area A1, and the ejection amount DT2 for the second area A2 is less than the ejection amount DT3 for the third area A3.

[0152] In the above-described manner, the control unit 10 determines the ejection amount DT of the base ink 36b for the region Ai by determining a provisional ejection amount PD that is independent of the position in the first direction D1 and multiplying the provisional ejection amount PD by the coefficient αi. By determining αi × PD as the ejection amount DT for each region Ai, the computational amount can be made smaller compared to the case where the ejection amount DT linearly changes across the entire processing unit region A0 in the first direction D1, and thus high-speed processing can be achieved.

[0153] After determining the ejection amount DT, the control unit 10 determines whether the processes of S104 to S108 have been performed for all the pixels of the image data DA1 (S110). If there are remaining pixels for which the processes of S104 to S108 have not been performed, the control unit 10 returns the process to S104.

[0154] If the processes of S104 to S108 have been performed for all the pixels, the control unit 10 performs a halftone process, which is a process of generating dot data that reduces the gray level of the obtained ink amount data to, for example, 2 or 4 (S112). The dot data is generated separately for C, M, Y, K, and W. After the halftone process, the control unit 10 performs a rasterization process, which is a process of generating raster data obtained by rearranging the dot data in such a way that a main scan for overlapping the base ink 36b on the image IM1 is performed after the main scan for forming the image IM1 (S114). For example, it is assumed that the printing unit 20 performs a second main scan for ejecting the base ink 36b after the first main scan for ejecting the colored ink 36a for each band in the processing unit region A0. In this case, the control unit 10 generates raster data obtained by rearranging the dot data in such a way that the colored ink 36a is ejected to form the image IM1 by the first main scan and the base ink 36b is ejected to be overlapped on the image IM1 by the second main scan.

[0155] Finally, the control unit 10 generates a drive signal SG1 based on the raster data and sends it to the inkjet head 30, thereby controlling the printing unit 20 to form the image IM1 on the transfer medium M1 and overlap the base ink 36b on the image IM1 (S116). The drive unit 50 relatively moves the inkjet head 30 with respect to the transfer medium M1 in such a way that main scanning and sub-scanning are performed according to the control implemented by the control unit 10. The colored ink head 31 ejects the colored ink 36a to form the image IM1 on the transfer medium M1 during the main scan, and the base ink head 32 ejects the base ink 36b to overlap the base ink 36b on the image IM1 during the main scan.

[0156] Here, by making the ejection amount DT2 of the second region A2, where the base ink 36b overlaps the image IM1 later than the first region A1 and the third region A3, smaller, it is possible to suppress the flow of the base ink 36b caused by the inclination of the transfer medium M1 in the adhesive application step ST3. As a result, it is possible to suppress the bleeding of the transfer image IM1 caused by the downward flow of the base ink 36b or the like, and thus the image quality of the transfer image IM1 is improved. In addition, by arranging the third region A3 with an ejection amount DT3 that is less than the ejection amount DT1 and more than the ejection amount DT2 between the first region A1 and the second region A2, the influence on the image quality of the transfer image IM1 due to the change in the ejection amount DT of the base ink is reduced, and thus the image quality of the transfer image IM1 is improved.

[0157] As Figure 12 illustrated, the printing apparatus 1 can accept the setting of the coefficient αi. Figure 12 The coefficient setting process is schematically illustrated. In Figure 12 it, a coefficient setting screen 500, which is a user interface screen for accepting the setting of the coefficient αi, is also illustrated. The coefficient setting process can be implemented either by the printer 2 or through the cooperation of the host device HO1 and the printer 2.

[0158] For example, when an instruction to set the coefficient αi is received from the operation panel 24, the control unit 10 of the printer 2 starts the coefficient setting process. First, the control unit 10 causes the output unit 25 of the operation panel 24 to display the coefficient setting screen 500. When the input unit 26 accepts an operation on the coefficient setting screen 500, a set value corresponding to the operation is obtained from the operation panel 24 (S202). The coefficient setting screen 500 has an input field 501 for the coefficient α1, an input field 502 for the coefficient α3, an input field 503 for the coefficient α2, an OK button 504, and the like. In the initial coefficient setting screen 500, the control unit 10 causes the input field 501 to display the coefficient α1 of the coefficient table T1, the input field 502 to display the coefficient α3 of the coefficient table T1, and the input field 503 to display the coefficient α2 of the coefficient table T1. The operation panel 24 accepts changes to the coefficient α1 in the input field 501, changes to the coefficient α3 in the input field 502, and changes to the coefficient α2 in the input field 502. When the operation panel 24 accepts an operation on the OK button 504, the coefficient α1 displayed in the input field 501, the coefficient α3 displayed in the input field 502, and the coefficient α2 displayed in the input field 503 are sent to the control unit 10.

[0159] The control unit 10 stores the coefficients α1 to α3 received from the operation panel 24 in the coefficient table T1 (S204), and ends the coefficient setting process. Thus, the base ink ejection amount DT can be calculated based on the set coefficient αi.

[0160] In addition, the host device HO1 can also start the coefficient setting process according to the setting instruction of the coefficient αi. In this case, in S202, the host device HO1 obtains the coefficient αi from the printer 2, and causes the display to display the coefficient setting screen 500, and accepts the operation on the coefficient setting screen 500 through an input device such as a keyboard, a pointing device, a touch panel, etc. When the host device HO1 accepts the operation of the OK button 504, in S204, the coefficients αi displayed in the input fields 501 to 503 are sent to the printer 2. The printer 2 that has received the coefficient αi only needs to store the coefficient αi in the coefficient table T1.

[0161] By implementing the above coefficient setting process, the base ink ejection amount DT can be adjusted according to the user's needs.

[0162] Regarding whether the transferred image IM1 becomes the intended image quality, in addition to the amount and composition of the base ink 36b, it is also affected by the amount and composition of the colored ink 36a, the amount and composition of the binder 111, etc. Therefore, strictly speaking, the coefficient αi needs to be determined considering a huge combination of the amount and composition of the ink 36, the type of the transfer medium M1, the amount and type of the binder 111, the type of the medium to be transferred M2, etc. By implementing the above coefficient setting process, it is not necessary to prepare the coefficient αi for all the huge combinations envisaged, so that the storage area for the coefficient αi can be smaller.

[0163] In addition, as Figure 13 illustrated, the ejection amount DT1 of the base ink 36b overlapping the image IM1 in the first region A1 is not limited to being constant, and the ejection amount DT2 of the base ink 36b overlapping the image IM1 in the second region A2 is also not limited to being constant. Figure 13 An example is schematically shown in which the base ink ejection amount DT is changed according to the size of the continuous region of the image IM1 in the same region.

[0164] Figure 13 The first region A1 shown includes a first continuous region A11 that is connected as an image IM1 in the first region A1, and a second continuous region A12 that is separated from the first continuous region A11 and is connected as an image IM1 in the first region A1. The second continuous region A12 is larger in area than the first continuous region A11.

[0165] Within the same first region A1, the larger the continuous region, the more likely it is for the base ink 36b to flow due to the inclination of the transfer medium M1 in the adhesive application step ST3. Therefore, the control unit 10 can also make the ejection amount DT12 of the base ink 36b per unit area for the second continuous region A12 less than the ejection amount DT11 of the base ink 36b per unit area for the first continuous region A11. Thereby, the flow of the base ink 36b caused by the inclination of the transfer medium M1 in the adhesive application step ST3 can be further suppressed.

[0166] Figure 13 The second region A2 shown includes a first continuous region A11 that is connected as an image IM1 within the second region A2, and a second continuous region A12 that is separated from the first continuous region A11 and is connected as an image IM1 within the second region A2. The second continuous region A12 is larger in area than the first continuous region A11.

[0167] Within the same second region A2, the larger the continuous region, the more likely it is for the base ink 36b to flow due to the inclination of the transfer medium M1 in the adhesive application step ST3. In particular, since the drying time of the base ink 36b in the second region A2 is short, the flow of the base ink 36b is likely to occur in the larger second continuous region A12. Therefore, the control unit 10 can also make the ejection amount DT22 of the base ink 36b per unit area for the second continuous region A12 less than the ejection amount DT21 of the base ink 36b per unit area for the first continuous region A11. Thereby, the flow of the base ink 36b caused by the inclination of the transfer medium M1 in the adhesive application step ST3 can be further suppressed.

[0168] In addition, either DT21 > DT22 in the second region A2 and DT11 = DT12 in the first region A1, or DT11 > DT12 in the first region A1 and DT21 = DT22 in the second region A2.

[0169] Also, in the case where the third region A3 includes a first continuous region A11 with a smaller area and a second continuous region A12 with a larger area, the ejection amount of the base ink per unit area for the second continuous region A12 can also be made less than the ejection amount of the base ink per unit area for the first continuous region A11.

[0170] Figure 14 The structure of the coefficient table T1 for changing the ejection amount DT of the base ink according to the size of the continuous region of the image IM1 within the same region is schematically illustrated.

[0171] Figure 14The coefficient table T1 shown has a coefficient α1 associated with the attachment of the first region A1, a coefficient α2 associated with the attachment of the second region A2, and a coefficient α3 associated with the attachment of the third region A3. Here, the coefficient αi varies according to the area of the continuous region. Regarding Figure 14 For the coefficient αi shown, compared with the first continuous region A11 where the area of the continuous region is less than the threshold THA, the coefficient is smaller for the second continuous region A12 where the area of the continuous region is equal to or greater than the threshold THA. For example, in the second region A2, the coefficient αi in the first continuous region A11 is 0.8, and the coefficient αi in the second continuous region A12 is 0.7. In addition, the coefficient αi within the same region can be switched in three or more stages or can vary linearly.

[0172] The Figure 14 print control process that refers to the coefficient table T1 shown can be implemented in accordance with Figure 11 the print control process shown. For example, in S102, the control unit 10 can extract the continuous regions included in the first region A1 based on the image data DA1, extract the continuous regions included in the second region A2, and extract the continuous regions included in the third region A3. On this basis, the control unit 10 can calculate the area of each continuous region before S108. The area of the continuous region can be obtained, for example, by counting the number of pixels contained in the continuous region. In each region Ai, when the area of the continuous region is less than the threshold THA, the control unit 10 determines that the continuous region is the first continuous region A11, and when the area of the continuous region is equal to or greater than the threshold THA, the control unit 10 determines that the continuous region is the second continuous region A12. In S108, the control unit 10 can calculate the base ink ejection amount DT by referring to the coefficient αi corresponding to the area of the continuous region in the region Ai from the coefficient table T1 and multiplying the coefficient αi by the tentative ejection amount PD of the base ink 36b. When Figure 14 referring to the coefficient table T1 shown, the control unit 10 applies the coefficient αi corresponding to less than the threshold THA in the first continuous region A11 and applies the coefficient αi corresponding to equal to or greater than the threshold THA in the second continuous region A12.

[0173] By implementing the print control process in the above manner, the flow of the base ink 36b caused by the inclination of the transfer medium M1 in the adhesive application process ST3 can be further suppressed, and thus the bleeding of the transfer image can be further suppressed.

[0174] As Figure 15As illustrated, the number of cycles NP of the processing unit area A0 is not limited to being constant, and may also vary according to the area. Here, the number of cycles NP refers to the number of main scans accompanied by the ejection of the base ink 36b that are performed at the same position in the transfer medium M1. Figure 15 An example of changing the number of cycles NP according to the ejection amount DT of the base ink per unit area is schematically shown. In Figure 15 it, a structural example of the cycle number table T2 for determining the number of cycles NP according to the ejection amount DT of the base ink is also shown. The case where the cycle number table T2 is used is the case where main scanning and sub-scanning are performed.

[0175] In Figure 15 the shown cycle number table T2, the correspondence between the ejection amount DT of the base ink and the number of cycles NP is defined. In the cycle number table T2, the number of cycles NP increases stepwise as the ejection amount W of the ejection amount DT of the base ink increases.

[0176] Figure 15 the shown processing unit area A0 includes a first ejection amount area AD1 where the ejection amount DT of the base ink per unit area is 40% of the first ejection amount, and a second ejection amount area AD2 where the ejection amount DT of the base ink per unit area is 80% of the second ejection amount. Here, the second ejection amount has a larger ejection amount DT of the base ink than the first ejection amount, and the second ejection amount area AD2 is located at a position different from the first ejection amount area AD1 in the first direction D1. As Figure 15 shown, the second area A2 is an example of the first ejection amount area AD1, and the first area A1 is an example of the second ejection amount area AD2. In addition, the third area A3 may be applied to the second ejection amount area AD2 when the second area A2 is applied to the first ejection amount area AD1, and the first area A1 may be applied to the second ejection amount area AD2 when the third area A3 is applied to the first ejection amount area AD1. The control unit 10 makes the number of cycles NP in the second ejection amount area AD2 more than the number of cycles NP in the first ejection amount area AD1.

[0177] For example, when the ejection amount DT of the base ink in the first ejection amount area AD1 is 40%, the control unit 10 sets the number of cycles NP to 4 according to the cycle number table T2. When the ejection amount DT of the base ink in the second ejection amount area AD2 is 80%, the control unit 10 sets the number of cycles NP to 8 according to the cycle number table T2. As Figure 15As shown, in the third ejection amount region where the ejection amount DT is larger than that in the first ejection amount region AD1 and smaller than that in the second ejection amount region AD2, for example, the number of cycles NP in the third region A3 may also be more than the number of cycles NP in the first ejection amount region AD1 and less than the number of cycles NP in the second ejection amount region AD2.

[0178] The printing control process that refers to the cycle number table T2 can be implemented in accordance with Figure 11 the printing control process shown. For example, in S112, the control unit 10 may calculate the average value of the ejection amount of the base ink 36b for the portion overlapped on the image IM1 for each region Ai based on the W data included in the CMYKW data, and refer to the cycle number table T2 using this average value as the base ink ejection amount DT. Thereafter, the control unit 10 may set the number of cycles NP corresponding to the base ink ejection amount DT for each region Ai, and generate dot data that reduces the gray level of the ink amount data to, for example, 2 or 4.

[0179] Since drying of the base ink 36b is promoted by increasing the number of cycles NP in the region where the base ink ejection amount DT is large, it is possible to further suppress the flow of the base ink 36b caused by the inclination of the transfer medium M1 in the adhesive application step ST3.

[0180] In addition, when the main scan can be stopped in the middle of the belt, the number of main scans can be changed within the belt. When the first ejection amount region AD1 and the second ejection amount region AD2 are set within one belt such that the first region A1 and the second region A2 are set within one belt, the control unit 10 may also control the number of main scans in the second ejection amount region AD2 to be more than the number of main scans in the first ejection amount region AD1. Since drying of the base ink 36b is promoted by increasing the number of main scans in the region where the base ink ejection amount DT is large, it is possible to further suppress the flow of the base ink 36b caused by the inclination of the transfer medium M1 in the adhesive application step ST3.

[0181] (4) Variation:

[0182] The present invention contemplates various variations.

[0183] For example, the main body that implements the above-described process is not limited to the CPU, and may be an electronic component other than the CPU such as an ASIC (Application Specific Integrated Circuit). Of course, it is also possible to implement the above-described process by having multiple CPUs work together, or by having the CPU work together with other electronic components (for example, an ASIC) to implement the above-described process.

[0184] Figure 11 A part of the printing control process shown can also be implemented by the host device HO1. In this case, the control unit of the printing device 1 becomes a combination of the control unit 10 in the narrow sense and the host device HO1.

[0185] The combination of the colors of the colored inks 36a is not limited to C, M, Y, and K, and may also include orange, green, light blue - green with a lower concentration compared to C, light magenta with a lower concentration compared to M, deep yellow with a higher concentration compared to Y, light black with a lower concentration compared to K, etc. Of course, in the case where the colored ink 36a does not include inks of some of the colors of C, M, Y, and K, the method of the present application can also be applied.

[0186] The base ink 36b is not limited to the W ink, and may also be a K ink containing a light - absorbing component, a gray ink containing a light - diffusing component and a light - absorbing component, etc. In addition, a transparent ink that allows the color of the transfer medium M2 that forms the background of the image IM1 to pass through but allows light to transmit can also be used as the base ink 36b.

[0187] Although Figure 13 、 14 An example of changing the base ink ejection amount DT according to the size of the continuous area of the image IM1 in the same area is shown, but the control unit 10 can also change the base ink ejection amount DT according to the color of the image IM1 in the same area.

[0188] Although the above - mentioned printing control process shows an example of changing the base ink ejection amount DT for each area Ai by adjusting the ink amount data related to the base ink 36b, the base ink ejection amount DT can also be changed for each area Ai in a manner other than this example. For example, after the control unit 10 generates CMYK data that does not include W data from RGB data and generates colored dot data for each of C, M, Y, and K from the CMYK data, the control unit 10 can generate 4 - value W dot data based on the colored dot data. Here, the control unit 10 generates W dot data with a large W dot in the pixels where colored ink 36a is generated for the first area A1, and generates W dot data with a medium - sized W dot in the pixels where colored ink 36a is generated for the second area A2. Thus, the base ink ejection amount DT can be made smaller in the second area A2 than in the first area A1. In addition, the control unit 10 can also make the base ink ejection amount DT smaller in the second area A2 than in the first area A1 by applying a data mask that reduces the generation rate of W dots for the second area A2.

[0189] (5) Summary:

[0190] As described above, according to the present invention, a structure capable of suppressing bleeding of a transferred image can be provided in various ways. Of course, the above-described basic functions and effects can also be obtained by a technique composed only of the constituent elements recited in the independent claims.

[0191] In addition, it is also possible to implement a structure obtained by mutually replacing the respective structures disclosed in the above examples or changing the combination, a structure obtained by mutually replacing a known technique and the respective structures disclosed in the above examples or changing the combination, and the like. The present invention also includes these structures and the like.

[0192] Reference Signs

[0193] 1... Printing apparatus; 2... Printer; 10... Control unit; 20... Printing unit; 30... Inkjet head; 31... Color ink head; 32... Base ink head; 33... Carriage; 34... Nozzle; 36... Ink; 36a... Color ink; 36b... Base ink; 37... Ink droplet; 50... Driving unit; 51... Main scanning driving unit; 52... Sub-scanning driving unit; 55... Conveying unit; 100... Adhesive supply device; 110... Adhesive tank; 111... Adhesive; 120... Heating unit; 200... Thermal transfer device; 500... Coefficient setting screen; A0, A01, A02, A03... Processing unit area; A1... First area; A2... Second area; A3... Third area; A11... First continuous area; A12... Second continuous area; AD1... First ejection amount area; AD2... Second ejection amount area; D1... First direction; D2... Second direction; D11... Outward direction; D12... Return direction; DA1... Image data; DT... Ejection amount; IM1... Image; L1, L2... Conveying amount; M1... Transfer medium; M2... Medium to be transferred; M11... Continuous paper; M12... Sheet paper; NP... Number of cycles; PD... Tentative ejection amount; ST1... Image forming process; ST2... Base forming process; ST3... Adhesive supply process; ST4... Heating process; ST5... Transfer process; T1... Coefficient table; T2... Number of cycles table; αi... Coefficient.

Claims

1. A printing method, which performs printing on a transfer medium by performing an adhesive application step and a transfer step, wherein the adhesive application step is a step of attaching an adhesive to a base ink, the base ink being superimposed on an image formed on the transfer medium, and the transfer step is a step of attaching the adhesive to a transfer medium to transfer the image to the transfer medium, wherein: The printing method comprises: An image forming step of forming the image on the transfer medium by ejecting colored ink from a first inkjet head; a base forming step of ejecting the base ink from a second inkjet head onto the transfer medium so as to overlap the base ink on the image; The process unit area includes a first area and a second area where the base ink is overlapped on the image at a later time than the first area. In the base forming step, the discharge amount of the base ink per unit area of ​​the second region is made smaller than the discharge amount of the base ink per unit area of ​​the first region.

2. The printing method according to claim 1, wherein: The first area includes a portion in the processing unit area where the base ink is first overlapped on the image. The second area includes a portion in the processing unit area where the base ink is finally overlapped on the image.

3. The printing method according to claim 1 or claim 2, wherein: At least one of the first area and the second area includes a first continuous area connected as the image in the area, and a second continuous area separated from the first continuous area and connected as the image in the area, The second continuous region is larger in area than the first continuous region, In the base forming step, the discharge amount of the base ink per unit area of ​​the second continuous region is made smaller than the discharge amount of the base ink per unit area of ​​the first continuous region.

4. The printing method according to claim 1 or claim 2, wherein: In the base forming step, a main scan is performed to cause the second inkjet head to eject the base ink while moving relative to the transfer medium in a second direction intersecting with a first direction in which the transfer medium moves relative to the second inkjet head, and a position where the base ink is overlapped on the image is changed toward the first direction by causing the second inkjet head to move relative to the transfer medium in the first direction in a sub-scan during the main scan. The second area is an area in which the base ink is overlapped on the image in the main scan that is later than the main scan in which the base ink is overlapped on the image located in the first area.

5. The printing method according to claim 1 or claim 2, wherein: In the base forming step, a main scan is performed to eject the base ink while the second inkjet head is moved relative to the transfer medium in the first direction. The second area is an area where the base ink is overlapped on the image later than the first area in the main scan in which the base ink is overlapped on the image located in the first area.

6. The printing method according to claim 1 or claim 2, wherein: In the base forming process, a provisional ejection amount of the base ink is determined in the processing unit area regardless of the position in the first direction, and the ejection amount of the base ink for the first area and the second area is determined by multiplying the coefficient corresponding to the position in the first direction by the provisional ejection amount.

7. The printing method according to claim 1 or claim 2, wherein: The base ink is an ink containing a component that blocks the transmission of light.

8. The printing method according to claim 1 or claim 2, wherein: In the base forming step, a main scan is performed to eject the base ink while the second inkjet head is moved relative to the transfer medium along a second direction intersecting the first direction, and a position where the base ink is overlapped on the image is changed toward the first direction by moving the second inkjet head relative to the transfer medium in the first direction in a sub-scan during the main scan. The processing unit area includes a first ejection amount area and a second ejection amount area, the first ejection amount area being an area where the ejection amount per unit area of ​​the base ink superimposed on the image is a first ejection amount, and the second ejection amount area being an area where the ejection amount per unit area of ​​the base ink superimposed on the image is a second ejection amount greater than the first ejection amount, the second discharge amount region is located at a position different from the first discharge amount region in the first direction, The number of main scans performed at the same position on the transfer medium accompanied by the ejection of the base ink is defined as the number of cycles. In the base forming step, the number of cycles in the second discharge amount range is set to be greater than the number of cycles in the first discharge amount range.

9. A printing device for printing on a transfer medium by performing an adhesive application step and a transfer step, wherein the adhesive application step is a step of attaching an adhesive to a base ink, the base ink being superimposed on an image formed on the transfer medium, and the transfer step is a step of attaching the adhesive to a transfer medium to transfer the image to the transfer medium, wherein: The printing device comprises: a first inkjet head that ejects colored ink; a second inkjet head for ejecting the base ink; a driving unit configured to move the second inkjet head relative to the transfer medium in a first direction; a control unit that controls the ejection of the color ink from the first inkjet head, the ejection of the base ink from the second inkjet head, and the drive unit, The control unit controls to form the image on the transfer medium using the colored ink ejected from the first inkjet head and to overlap the base ink ejected from the second inkjet head on the image. The process unit area includes a first area and a second area where the base ink is overlapped on the image at a later time than the first area. The control unit makes the ejection amount of the base ink per unit area of ​​the second region smaller than the ejection amount of the base ink per unit area of ​​the first region.

Images