Printing system and printing method

Abstract

Suppresses deterioration in the quality of transcription results. [Solution] The print head is capable of forming an image to be transferred to a transfer medium, an undercoat ink layer to which an adhesive is applied, and a damming structure having protrusions that dam up at least a portion of the flow of the undercoat ink layer. The control unit performs a first control to form the image on the transfer medium by causing the print head to eject image-forming ink, a second control to form the damming structure in contact with at least a portion of the image on the transfer medium having the image by causing the print head to eject damming ink, and a third control to form the undercoat ink layer on the transfer medium having the image and the damming structure by causing the print head to eject base ink.

Description

[Technical Field]

[0001] The present invention relates to a printing system and a printing method for printing on a transfer medium. [Background technology]

[0002] A known printing system is a transfer system that transfers an image to a receiving medium using the DTF (Direct to Film) method. This transfer system prints an image and a white base ink layer on the transfer medium using an inkjet method, adheres a powdered hot melt adhesive to the wet base ink layer, and transfers the image to the receiving medium using a thermal transfer device. Patent Document 1 discloses a printing system equipped with a clear ink head that ejects colorless, translucent clear ink instead of white ink. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-87372 Summary of the Invention [Problem to be solved by the invention]

[0004] The base ink layer must be wet when the powder adhesive is applied to it, because the powder adhesive will not adhere to the base ink layer if the base ink layer dries. However, if the base ink layer is wet, tilting the transfer medium to apply the powder adhesive or vibrating the transfer medium to shake off excess powder adhesive can cause the base ink layer to spread, potentially degrading image quality. [Means for solving the problem]

[0005] The printing system of the present invention is a printing system that forms, on a transfer medium, an image to be transferred to a transfer medium and a base ink layer to which an adhesive is attached, and a print head capable of ejecting a plurality of types of ink capable of forming the image, the base ink layer, and a damming structure having a protrusion that dams at least a portion of the flow of the base ink layer; a drive unit that changes the relative positional relationship between the print head and the transfer medium; a control unit that controls the ejection of the ink from the print head and the drive unit, Among the plurality of types of ink, ink for forming the image is referred to as image forming ink, ink for forming the base ink layer is referred to as base ink, and ink for forming the damming structure is referred to as damming ink, The control unit a first control for forming the image on the transfer medium by ejecting the image forming ink from the print head; a second control for forming the damming structure on the transfer medium having the image thereon by ejecting the damming ink from the print head, the damming structure being in contact with at least a portion of the image; a third control for forming the base ink layer on the transfer medium having the image and the damming structure by ejecting the base ink from the print head; The present invention has an aspect of carrying out the above.

[0006] The printing method of the present invention is a printing method for changing the relative positional relationship between a print head and a transfer medium, and forming an image to be transferred to a transfer medium and an undercoat ink layer to which an adhesive is to be attached on the transfer medium, the method comprising: the print head is capable of ejecting a plurality of types of ink capable of forming the image, the base ink layer, and a damming structure having a protrusion that dams at least a portion of the flow of the base ink layer; Among the plurality of types of ink, ink for forming the image is referred to as image forming ink, ink for forming the base ink layer is referred to as base ink, and ink for forming the damming structure is referred to as damming ink, The printing method includes: a first step of forming the image on the transfer medium by ejecting the image forming ink from the print head; a second step of ejecting the damming ink from the print head to form the damming structure on the transfer medium having the image thereon, the damming structure being in contact with at least a portion of the image; a third step of ejecting the base ink from the print head to form the base ink layer on the transfer medium having the image and the damming structure; The present invention has an aspect including the following. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram schematically illustrating an example of the configuration of a printing system. [Figure 2] FIG. 1 is a plan view schematically illustrating an example of the configuration of a printer. [Figure 3] FIG. 2 is a bottom view schematically illustrating an example of a nozzle surface of a print head. [Figure 4] FIG. 1 is a block diagram illustrating a configuration example of a printing apparatus. [Figure 5] 1A to 1C are diagrams illustrating an example of a printing method on a transfer medium. [Figure 6] FIG. 10 is a plan view schematically showing an example of printing in which the range of the damming structure is set wider than the range of the base ink layer. [Figure 7] FIG. 10 is a cross-sectional view schematically showing an example of printing in which the range of the blocking structure is set wider than the range of the base ink layer. [Figure 8] FIG. 10 is a plan view schematically showing an example of printing in which the range of the damming structure is adjusted to the range of the base ink layer. [Figure 9] FIG. 10 is a cross-sectional view schematically showing an example of printing in which the range of the damming structure is matched with the range of the base ink layer. [Figure 10] 10 is a flowchart illustrating an example of a print control process. [Figure 11] FIG. 10 is a plan view schematically showing an example in which the protruding portions of the blocking structure are printed in a divided form. [Figure 12] FIG. 10 is a plan view schematically showing an example in which a damming structure is arranged according to the shape of a base ink layer. [Figure 13] FIG. 10 is a plan view schematically showing an example in which a damming structure is arranged according to the size of the base ink layer. [Figure 14] FIG. 10 is a plan view schematically showing an example in which the arrangement of the damming structure is changed between the upstream region and the downstream region. [Figure 15] FIG. 10 is a cross-sectional view schematically illustrating an example of printing in which a damming structure is inserted into a hole in an image. [Figure 16] FIG. 10 is a cross-sectional view schematically showing how the underlying ink layer spreads in a wet state in a comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0008] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following describes embodiments of the present invention. Of course, the following embodiments are merely examples of the present invention, and not all of the features shown in the embodiments are necessarily essential to the solution of the invention.

[0009] (1) Summary of the aspects included in the present invention: First, an overview of the embodiments included in the present invention will be described with reference to the examples shown in Figures 1 to 16. The figures in the present application are diagrams showing examples in a schematic manner, and the scale of each part may differ from the actual scale in order to make each part of these figures large enough to be recognizable. The magnification in each direction shown in these figures may differ, and the figures may not be consistent with each other. Of course, each element of the present embodiment is not limited to the specific example indicated by a symbol. In the "Outline of the embodiments included in the present invention," the words in parentheses indicate supplementary explanations for the immediately preceding words. In addition, in the present application, a numerical range "Min to Max" means a value equal to or greater than the minimum value Min and equal to or less than the maximum value Max.

[0010] [Aspect 1] As illustrated in FIG. 1 and other figures, a printing system SY1 according to one embodiment forms, on a transfer medium M1, an image IM1 to be transferred to a transfer medium M2 and an undercoat ink layer UC1 to which an adhesive 111 is applied, and includes a print head 30, a drive unit 50, and a control unit 10. As illustrated in FIGS. 3 and 5 and other figures, the print head 30 is capable of ejecting multiple types of ink 36 capable of forming the image IM1, the undercoat ink layer UC1, and a damming structure DM1 having protrusions TP1 that dam at least a portion of the flow of the undercoat ink layer UC1. The drive unit 50 changes the relative positional relationship between the print head 30 and the transfer medium M1. The control unit 10 controls the ejection of the ink from the print head 30 and the drive unit 50. Here, among the plurality of types of ink 36, the ink for forming the image IM1 is defined as an image forming ink (for example, colored ink 36a), the ink for forming the base ink layer UC1 is defined as a base ink 36b, and the ink for forming the damming structure DM1 is defined as a damming ink 36c. The control unit 10 performs the following control, as exemplified in FIGS. 5 to 9. (a1) A first control (for example, a first step ST1) in which the image forming ink (36a) is ejected from the print head 30 to form the image IM1 on the transfer medium M1. (a2) A second control (e.g., a second process ST2) in which the damming ink 36c is ejected from the print head 30 to form the damming structure DM1 that contacts at least a portion of the image IM1 on the transfer medium M1 having the image IM1. (a3) A third control (for example, a third step ST3) in which the base ink 36b is ejected from the print head 30 to form the base ink layer UC1 on the transfer medium M1 having the image IM1 and the damming structure DM1.

[0011] By ejecting the damming ink 36c onto the transfer medium M1 bearing the image IM1 before the base ink 36b, the damming ink 36c dries, forming a damming structure DM1 having protrusions TP1 that block at least a portion of the flow of the base ink layer UC1. This suppresses the flow of the base ink layer UC1, which requires wettability to allow the adhesive 111 to adhere, and maintains the quality of the image IM1. Therefore, the above-described embodiment can provide a printing system that can suppress deterioration in the quality of the transfer result.

[0012] Various examples of the above-described aspect are possible. Changes in the relative positional relationship between the print head and the transfer medium include the print head moving without the transfer medium moving, the transfer medium moving without the print head moving, and both the print head and the transfer medium moving. The base ink may be an ink other than the image forming ink, or may be an ink that is also used as the image forming ink. The blocking ink may be an ink other than the image forming ink, or may be an ink that is also used as the image forming ink. The damming structure only needs to be in contact with at least a portion of the image, and may be present around the image on the transfer medium, on the image itself, or both around and on the image. The dammed ink may be ejected partially onto the area on the transfer medium that includes the image, or onto the entire area on the transfer medium that includes the image. The convex portions of the damming structure only need to be higher than the surrounding area. Therefore, the image may be present around the convex portions, or the dammed ink may be present. By having the convex portions higher than the surrounding area, at least a portion of the flow of the wet base ink layer is dammed. In this application, the terms "first," "second," etc. are terms for distinguishing between elements among a plurality of elements having similarities, and do not necessarily imply an order. Of course, the above remarks also apply to the following aspects.

[0013] [Aspect 2] The control unit 10 may complete the formation of the damming structure DM1 in the second control, and then start the formation of the base ink layer UC1 in the third control. In the above case, the damming structure DM1 becomes stronger as the drying of the formed damming structure DM1 progresses, and the flow of the base ink layer UC1 is further suppressed. Therefore, the above aspect can further suppress the deterioration of the quality of the transfer result.

[0014] [Aspect 3] The blocking ink 36c may be a clear ink that does not contain a coloring material. In the above case, the damming ink 36c does not affect the color of the image IM1, so that deterioration in the quality of the transfer result can be further suppressed.

[0015] [Aspect 4] As exemplified in FIGS. 6 and 7, an area 302 in which the damming structure DM1 is formed may be larger than an area 301 in which the base ink layer UC1 is formed. In this case, the flow of the base ink layer UC1 is further suppressed by the damming structure DM1 in the formation range 302, which is wider than the formation range 301 of the base ink layer UC1. Therefore, the above embodiment can further suppress deterioration in the quality of the transfer result. Here, when the damming structure DM1 has an opening (for example, the opening OP1 illustrated in FIG. 6), the formation range of the damming structure DM1 means the range including the opening. This statement also applies to the following aspects.

[0016] [Aspect 5] The blocking ink 36c may be an ink having a higher viscosity than the base ink 36b. In the above case, when the damming ink 36c lands on the transfer medium M1 bearing the image IM1, the damming ink 36c is less likely to flow, making the damming structure DM1 even stronger and further suppressing the flow of the base ink layer UC1. Therefore, the above embodiment can further suppress deterioration in the quality of the transfer result.

[0017] [Aspect 6] As illustrated in Figures 6 and 8, in the second control, the control unit 10 may form the damming structure DM1 on the transfer medium M1 having the image IM1 by ejecting the damming ink 36c from the print head 30 so that the ink usage amount Q1 is less than the ink usage amount Q2 of the base ink layer UC1. In the above case, the damming ink 36c dries easily, so the damming structure DM1 becomes stronger and the flow of the base ink layer UC1 is further suppressed. Therefore, the above embodiment can further suppress the deterioration of the quality of the transfer result.

[0018] Here, the amount of ink used refers to the total amount of ink used in the area corresponding to the single connected base ink layer UC1. Therefore, the amount of ink used by the damming structure DM1 refers to the total amount of damming ink 36c used in the area corresponding to the single connected base ink layer UC1. The total amount of ink can be calculated from the number of ink droplets of a predetermined size ejected, or, if the ink droplet size is changeable, from the number of ink droplets ejected converted to the predetermined size. The above remarks also apply to the following aspects.

[0019] [Aspect 7] As illustrated in Figures 6, 11, etc., the damming structure DM1 may be a structure in which the convex portion TP1 intersects with a virtual straight line LN1 along the transfer medium M1 and passing through the image IM1 at three or more points. In the above case, when the transfer medium M1 is tilted so that the height changes between the upstream side and the downstream side in the direction along the virtual straight line LN1, the protrusions TP1 of the blocking structure DM1 block the flow of the base ink layer UC1 at three or more locations, further suppressing the flow of the base ink layer UC1. Therefore, the above aspect can further suppress deterioration in the quality of the transfer result.

[0020] [Aspect 8] 1, the printing system SY1 may further include an adhesive applicator (e.g., adhesive tank 110) that applies the adhesive 111 to the transfer medium M1 having the base ink layer UC1. The drive unit 50 may include a transport unit 55 that transports the transfer medium M1 having the base ink layer UC1 in a transport direction (e.g., first direction D1) from a position facing the print head 30 toward the adhesive applicator (110). As exemplified in FIGS. 6, 11, etc., the damming structure DM1 may be structured such that the protrusions TP1 intersect the virtual straight line LN1 along the transport direction (D1) at three or more locations. When the transfer medium M1 having the base ink layer UC1 is transported from a position facing the print head 30 to the adhesive application section (110), the transfer medium M1 often tilts so that its height changes between the upstream and downstream sides in the transport direction (D1). When the transfer medium M1 tilts so that its height changes between the upstream and downstream sides in the transport direction (D1), the protruding portions TP1 of the damming structure DM1 block the flow of the base ink layer UC1 at three or more locations, further suppressing the flow of the base ink layer UC1. Therefore, the above-described embodiment can further suppress deterioration in the quality of the transfer result.

[0021] [Aspect 9] 12, the region of the damming structure DM1 may include a first region A1 and a second region A2 through which the base ink layer UC1 flows more easily than the first region A1 due to the shape of the base ink layer UC1. In the second control, the control unit 10 may make the amount of the damming ink 36c per unit area required to form the convex portions TP1 in the second region A2 greater than the amount of the damming ink 36c per unit area required to form the convex portions TP1 in the first region A1. In the above case, the convex portion TP1 with a relatively large amount of ink present in the second area A2 where the base ink layer UC1 is likely to flow out effectively suppresses the flow of the base ink layer UC1, thereby further suppressing deterioration in the quality of the transfer result. Incidentally, the above-mentioned mode 9 also includes a case where the damming ink 36c is not used in the first region A1.

[0022] [Aspect 10] 13, the image IM1 may include a first image IM11 and a second image IM12 that is larger than the first image IM11. In the second control, the control unit 10 may increase the amount of the damming ink 36c per unit area required to form the convex portions TP1 in the region of the damming structure DM1 that corresponds to the second image IM12, compared to the amount of the damming ink 36c per unit area required to form the convex portions TP1 in the region of the damming structure DM1 that corresponds to the first image IM11. The larger the image IM1, the more likely the base ink layer UC1 corresponding to the image IM1 flows out. In the above embodiment, the protrusions TP1 with a relatively large amount of ink present in the area corresponding to the relatively large second image IM12 effectively suppress the flow of the base ink layer UC1, thereby further suppressing deterioration in the quality of the transfer result.

[0023] [Aspect 11] 1, the transfer medium M1 sent out from the transport unit 55 may be lowered and then the adhesive 111 may be applied. As illustrated in FIG. 14, the region of the base ink layer UC1 corresponding to the image IM1 may include a third region (e.g., an upstream region A3) and a fourth region (e.g., a downstream region A4) located downstream of the third region (A3) in the transport direction (D1). In the second control, the control unit 10 may make the amount of the damming ink 36c per unit area required to form the convex portions TP1 in the fourth region (A4) greater than the amount of the damming ink 36c per unit area required to form the convex portions TP1 in the third region (A3). When the adhesive 111 is applied to the transfer medium M1 after the transfer medium M1 sent out from the transport section 55 has descended, the base ink layer UC1 tends to flow downstream. In the above embodiment, the convex portions TP1 with a relatively large amount of ink present in the fourth area (A4) on the downstream side where the base ink layer UC1 tends to flow out effectively suppress the flow of the base ink layer UC1, thereby further suppressing deterioration in the quality of the transfer result.

[0024] [Aspect 12] As illustrated in Figures 1, 5, etc., one embodiment of a printing method is a printing method that changes the relative positional relationship between the print head 30 and the transfer medium M1, and forms an image IM1 to be transferred to the transfer medium M2, and a base ink layer UC1 to which adhesive 111 is attached, on the transfer medium M1, and includes the following steps. (b1) A first step ST1 of forming the image IM1 on the transfer medium M1 by ejecting the image forming ink (36a) from the print head 30. (b2) A second process ST2 in which the damming ink 36c is ejected from the print head 30 to form the damming structure DM1 on the transfer medium M1 having the image IM1, the damming structure DM1 being in contact with at least a portion of the image IM1. (b3) A third process ST3 in which the base ink 36b is ejected from the print head 30 to form the base ink layer UC1 on the transfer medium M1 having the image IM1 and the damming structure DM1. The above aspect can provide a printing method that can suppress deterioration in the quality of the transfer result.

[0025] Furthermore, the above-described aspects are applicable to a control method for the above-described printing system, a control program for the above-described printing system, a printing device including a print head, a drive unit, and a control unit, a control method for the printing device, a control program for the above-described printing device, a computer-readable non-transitory medium on which any of the above-described control programs is recorded, etc. Also, the above-described printing device may be composed of multiple distributed parts.

[0026] (2) Examples of printing devices: 1 shows a schematic configuration of a printing system SY1 that forms an image IM1 on a transfer medium M1 and transfers the image IM1 to a transfer receiving medium M2. The printing system SY1 includes at least a printing device 1, and may also include an adhesive applying device 100 or a thermal transfer device 200. The printing device 1 may be a standalone printer 2, or may be configured with a printer 2 and a host device HO1. The host device HO1 shown in FIG. 1 generates image data DA1 corresponding to the image IM1 to be transferred and transmits the image data DA1 to the printer 2. Hereinafter, the image IM1 to be transferred will also be referred to as the transferred image IM1. The printer 2 includes a print head 30, a drive unit 50, and a control unit 10, and forms an image IM1 corresponding to the image data DA1 on a transfer medium M1. The adhesive applicator 100 includes an adhesive tank 110 that applies adhesive 111 to the ink on the transfer medium M1, and a heating unit 120 that heats the transfer medium M1 after the adhesive has been applied. The adhesive tank 110 is an example of an adhesive applicator that applies adhesive 111 to the transfer medium M1, which has a base ink layer. The thermal transfer device 200 transfers the image IM1 from the transfer medium M1 to a transfer recipient medium M2.

[0027] The transfer medium M1 can be a transfer film or the like onto which an image can be transferred by a DTF (Direct to Film) method. A suitable transfer film is a resin film such as a PET (polyethylene terephthalate) film. Of course, the material of the transfer medium M1 may contain paper, metal, or the like in addition to resin, and the transfer medium M1 may be a metal film or the like. The adhesive 111 can be a powdery adhesive such as a powdery hot melt adhesive. A hot melt adhesive is a thermoplastic resin powder that melts when heated above its melting point and solidifies when cooled. The hot melt adhesive can be an adhesive containing one or more thermoplastic resins selected from polyurethane resin, polyolefin resin, polyamide resin, polyester resin, and the like. The transfer medium M2 can be a fabric such as a knitted or woven fabric, a nonwoven fabric, or a processed fabric such as a T-shirt.

[0028] As will be described in detail later, the printing device 1 performs a first step ST1, a second step ST2, and a third step ST3. The adhesive applying device 100 performs an adhesive applying step ST4 and a heating step ST5. The thermal transfer device 200 performs a transfer step ST6.

[0029] FIG. 2 is a plan view that schematically illustrates the configuration of a printer 2 equipped with a print head 30. Note that the processing unit area A0 shown in FIG. 2 is a rectangle with a length L0 and a width W0. FIG. 3 is a bottom view that schematically illustrates the nozzle surface 30a of the print head 30. FIG. 4 is a block diagram that schematically illustrates the configuration of the printing device 1. FIG. 5 schematically illustrates a method of printing on a transfer medium M2. The print head 30 shown in Figures 2 to 4 is an inkjet head capable of ejecting multiple types of ink 36, and the printer 2 is an inkjet printer that ejects liquid ink droplets 37. The printer 2 comprises a control unit 10, a printing unit 20, a RAM (Random Access Memory) 21 which is a semiconductor memory, a communication I / F (interface) 22, a storage unit 23, an operation panel 24, etc. The control unit 10, RAM 21, communication I / F 22, storage unit 23, and operation panel 24 are connected to a bus, allowing information to be input and output to and from each other. The printing unit 20 comprises the print head 30 and a drive unit 50.

[0030] The control unit 10 includes a CPU (Central Processing Unit) 11, which is 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 configured with an SoC (System on a Chip), etc. Based on image data DA1 acquired from either a host device HO1 or an external memory (not shown), the control unit 10 controls the print head 30 and the drive unit 50 so that an image IM1 of colored ink 36a, a damming structure DM1 (see FIGS. 6 to 9), and a base ink layer UC1 (see FIGS. 6 to 9) to which an adhesive 111 is attached are formed on the transfer medium M1. The colored ink 36a is an example of an image forming ink for forming the image IM1 to be transferred to the transfer medium M2. The image data DA1 may include, for example, two colors of R (red), G (green), and B (blue) for each pixel. 8 RGB data having integer values ​​of gray scale can be applied.

[0031] The CPU 11 is a device that centrally performs information processing and control in the printer 2. The color conversion unit 12 has a color conversion LUT (lookup table) that defines the correspondence between, for example, R, G, and B gradation values ​​and C (cyan), M (magenta), Y (yellow), K (black), and W (white) gradation values. In the color conversion LUT, the W gradation value is, for example, a value that indicates that the base ink 36b is used when at least one of the colored inks 36a among C, M, Y, and K is used. The base ink 36b is an ink for forming the base ink layer UC1, and in this specific example, it is W ink. As an example of a color conversion LUT, when the C, M, Y, and K gradation values ​​are 0, indicating that no colored ink is used, the W gradation value may be 0, indicating that no base ink is used, and in the remaining cases, the W gradation value may be 128, indicating that 50% base ink is used. This allows the base ink 36b to be overlaid at the position of the image IM1. Of course, the ejection amount of the base ink 36b superimposed on the image IM1 may be less than 50% or more than 50% within a range in which a transfer image IM1 of good image quality can be obtained. The color conversion unit 12 refers to the color conversion LUT and converts the RGB data into, for example, 2 8 The ink volume data is converted into ink volume data having integer values ​​of gradation. The ink volume data represents the amounts of C, M, Y, K, and W inks 36 used in units of pixels. Note that the inks 36 shown in FIG. 4 include C, M, Y, and K colored inks 36a and base ink 36b. Furthermore, if the resolution of the RGB data differs 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 volume data to the printing resolution.

[0032] The halftone processing unit 13 performs halftone processing on the ink amount data using a dithering method, error diffusion method, or the like to generate dot data with the number of gradations reduced to, for example, 2 or 4. Dot data is generated for each of C, M, Y, K, and W. The dot data represents the formation state of dots of ink 36 in pixel units. The dot data may be binary data representing the presence or absence of dot formation, or may be multi-valued data with three or more gradations that can correspond to dots of different sizes, such as small, medium, and large dots. The W dot data is an example of base data DA3 (see Figure 6) that represents the formation state of dots of base ink 36b in pixel units. Furthermore, the halftone processing unit 13 generates damming structure data DA2 (see FIG. 6) that represents the dot formation state of the damming ink 36c in pixel units based on the dot data or ink volume data. The damming ink 36c is ink for forming the damming structure DM1. In this specific example, the damming ink 36c is CL (clear) ink that does not contain colorant, and can be considered CL dot data. Details of the process for generating the damming structure data DA2 will be described later. The rasterization processing unit 14 generates raster data by performing a rasterization process that rearranges the dot data for each of C, M, Y, K, W, and CL in the order in which dots are formed by the drive unit 50.

[0033] The drive signal transmission unit 15 generates, from the raster data, a drive signal SG1 that corresponds to a voltage signal to be applied to the drive elements 42 of the print head 30, and outputs this to the drive circuit 41 of the print head 30. For example, if the raster data is for "large dot formation," the drive signal transmission unit 15 outputs a drive signal SG1 that causes ink droplets for large dots to be ejected, and if the raster data is for "small dot formation," the drive signal transmission unit 15 outputs a drive signal SG1 that causes ink droplets for small dots to be ejected. The RAM 21 stores image data DA1 and the like received from the host device HO1 and the like. The communication I / F 22 inputs and outputs information to and from the host device HO1 and the like. 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 may 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 that displays information, an input unit 26 such as a touch panel that accepts operations on the display screen, and the like.

[0034] The drive circuit 41 applies a voltage signal to the drive element 42 in accordance with the drive signal SG1 input from the drive signal transmission unit 15. The drive element 42 may be a piezoelectric element that applies pressure to the ink 36 in a pressure chamber that communicates with the nozzle 34, or a drive element that uses heat to generate bubbles in the pressure chamber and eject ink droplets 37 from the nozzle 34. Ink 36 is supplied to the pressure chamber of the print head 30 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 by the drive element 42. When the ink droplets 37 land on the transfer medium M1, dots are formed on the transfer medium M1. When dots of colored ink 36a are formed on the transfer medium M1, an image IM1 represented by a dot pattern is formed on the transfer medium M1.

[0035] The print head 30 shown in FIG. 3 includes a color ink head 31 that ejects color ink 36a, a base ink head 32 that ejects base ink 36b, and a blocking ink head 40 that ejects blocking ink 36c. The color ink heads 31 include 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. Each ink head (31C, 31M, 31Y, 31K, 40, 32) has a nozzle row in which multiple nozzles 34 are arranged in a nozzle arrangement direction that intersects with a second direction D2 (the scanning direction), for example, a first direction D1. The multiple nozzles 34 of each ink head may be arranged in a staggered pattern in the nozzle arrangement direction, in other words, in two rows in the nozzle arrangement direction. The nozzle arrangement direction may be offset from the first direction D1 by less than 90°. Each nozzle 34 of the color ink head 31 ejects color ink 36a as ink droplets 37, each nozzle 34 of the base ink head 32 ejects base ink 36b as ink droplets 37, and each nozzle 34 of the damming ink head 40 ejects damming ink 36c as ink droplets 37. The print head 30 shown in Figures 2 to 4 is mounted on a carriage 33. When the printer 2 performs lateral printing, the carriage 33 is movable along a second direction D2 as the main scanning direction and a first direction D1 as the sub-scanning direction.

[0036] The lateral-type driver 50 includes a main-scan driver 51, a sub-scan driver 52, and a transport unit 55, and changes the relative positional relationship between the print head 30 and the transfer medium M1. The main-scan driver 51 shown in FIG. 2 performs main scanning, ejecting ink 36 from the print head 30 in at least one of the forward direction D11 and the backward direction D12 while moving the print head 30 along a second direction D2 (the main scanning direction). The sub-scan driver 52 shown in FIG. 2 performs sub-scanning, moving the print head 30 along a first direction D1 (the sub-scanning direction) between main scans. That is, the print head 30 moves intermittently along the first direction D1 during sub-scanning. The transport unit 55 transports the transfer medium M1, which has a base ink layer UC1, from a position facing the print head 30 toward the adhesive tank 110 in the first direction D1. The transport unit 55 shown in FIG. 2 transports the transfer medium M1, which is continuous paper, along the first direction D1 between printing of the processing unit area A0. That is, when not printing, the transfer medium M1 moves intermittently along a first direction D1. A transport unit 55 shown in Figures 2 and 4 feeds the transfer medium M1 in the first direction D1 along a transport path 59. A platen 58 is located below the transport path 59 and supports the transfer medium M1 by contacting the transfer medium M1 on the transport path 59. A print head 30 controlled by the control unit 10 ejects ink droplets 37 toward the transfer medium M1 supported by the platen 58, thereby depositing ink 36 on the transfer medium M1. The control unit 10 controls the ejection of the color ink 36 a from the color ink head 31 , the ejection of the base ink 36 b from the base ink head 32 , the ejection of the damming ink 36 c from the damming ink head 40 , and the drive unit 50 .

[0037] The damming ink head 40 may be positioned in various ways as long as it can form a damming structure DM1 that contacts at least a portion of the image IM1 made of colored ink 36a, as illustrated in Figures 6 to 9. For example, the damming ink head 40 may be positioned in a direction facing the forward direction D11 from the C ink head 31C shown in Figure 3, or in a direction facing the colored ink head 31 in the opposite sub-scanning direction. The base ink head 32 may be positioned in various ways as long as it can directly or indirectly overlay the base ink 36b on the image IM1. For example, the base ink head 32 may be positioned facing the forward direction D11 from the C ink head 31C shown in Figure 3, or facing the direction opposite the sub-scanning direction from the color ink head 31.

[0038] The colored ink 36a ejected from the colored ink head 31 is an ink containing a coloring material such as a pigment as a dispersoid or solute in a liquid (e.g., water) that serves as a dispersion medium or solvent. To maintain the pigment in a dispersed state, the colored ink 36a may contain a thickener such as an anionic water-soluble polymer with a cellulose structure, such as carboxymethyl cellulose. The colored ink 36a includes, for example, chromatic inks C, M, and Y, and an achromatic ink K. The base ink 36b ejected from the base ink head 32 is an ink containing a component that blocks light transmission, such as a W ink containing a component that diffuses light. The W ink is an ink containing a white pigment, such as titanium oxide or zinc oxide, as a dispersoid in a liquid, such as water, as a dispersion medium. To maintain the pigment dispersion, the base ink 36b may contain a thickener, such as an anionic water-soluble polymer with a cellulose structure, such as carboxymethyl cellulose. Because the base ink 36b blocks light transmission, the color of the transfer medium M2, which forms the background of the image IM1, does not affect the color of the image IM1, resulting in a transfer medium M2 with high image quality. The base ink layer UC1 formed by the base ink 36b can also be considered a receiving layer that receives the adhesive 111 while in a wet state, with a viscosity sufficient to allow the adhesive 111 to adhere.

[0039] However, when there is no damming structure DM1 as in the comparative example shown in Fig. 16, the base ink layer UC1 on the image IM1 is in a wet state, and therefore the base ink layer UC1 may spread. Fig. 16 schematically shows how the wet base ink layer UC1 spreads in the comparative example. Because the powder adhesive will not adhere to the base ink layer UC1 if the base ink layer UC1 dries, the base ink layer UC1 must be wet when the powder adhesive is applied to the base ink layer UC1. However, if the transfer medium M1 is tilted to apply the powder adhesive, dripping of the base ink (e.g., W ink) may occur, potentially degrading the quality of the image IM1 by causing staining of the image IM1. Even if the transfer medium M1 is vibrated to shake off the excess powder adhesive, the base ink layer UC1 may spread, potentially degrading the quality of the image IM1 by causing staining of the image IM1.

[0040] Therefore, as illustrated in Figures 6 to 9, the printing system SY1 of this specific example forms a damming structure DM1 on a transfer medium M1 bearing an image IM1, the damming structure having protrusions TP1 that block at least a portion of the flow of the base ink layer UC1. The damming structure DM1 is formed by damming ink 36c ejected from a damming ink head 40 so as to contact at least a portion of the image IM1. Because the damming ink 36c is ejected before the base ink 36b, the damming ink 36c dries faster, forming the damming structure DM1 with protrusions TP1 that block at least a portion of the flow of the base ink layer UC1. Because the damming structure DM1 is formed after the image IM1 is formed but before the base ink layer UC1 is formed, it can also be called a dam layer. The presence of the damming structure DM1 prevents the outflow of the fluid base ink 36b present in the wet base ink layer UC1, even if the transfer medium M1 is tilted or vibrated, as shown in Fig. 16. Since the flow of the base ink layer UC1 is prevented in this way, the quality of the image IM1 is maintained, and deterioration in the quality of the transfer result is prevented.

[0041] The blocking ink 36c may be any ink that has little effect on the color of the image IM1. CL ink is preferred because it minimizes the effect on the color of the image IM1, but the colored ink 36a used in the image IM1 may also be used. The CL ink does not contain any colorant and is essentially colorless. It is a translucent ink that uses the same dispersion medium (e.g., water) as the colored ink 36a and W ink as its solvent. The CL ink may contain a thickener, such as a cellulose-structured anionic water-soluble polymer, such as carboxymethyl cellulose, to increase its viscosity.

[0042] The damming ink 36c may have a higher viscosity than the base ink 36b. For example, the base ink 36b may contain a white pigment and an anionic water-soluble polymer with a cellulose structure as a dispersion medium, using water. The damming ink 36c may also contain the same anionic water-soluble polymer with a cellulose structure as the base ink 36b, using water as a solvent. By increasing the content of the anionic water-soluble polymer with a cellulose structure in the damming ink 36c compared to the content of the anionic water-soluble polymer with a cellulose structure in the base ink 36b, the viscosity of the damming ink 36c can be made higher than that of the base ink 36b. Increasing the content of the anionic water-soluble polymer with a cellulose structure increases the viscosity of the ink, while decreasing the content of the anionic water-soluble polymer with a cellulose structure decreases the viscosity of the ink. The base ink 36b and the damming ink 36c may contain the anionic water-soluble polymer with a cellulose structure as a 10% by mass aqueous solution. This 10% by mass aqueous solution may have a viscosity of 600 mPa·s or less at a liquid temperature of 20° C. As an example, an ink containing 0.1 to 6.0% by mass of the 10% by mass aqueous solution may be used as the base ink 36b, and an ink containing 6.1% by mass or more of the 10% by mass aqueous solution may be used as the blocking ink 36c.

[0043] As a result, ink whose viscosity is adjusted to be higher than that of the base ink 36b can be used as the damming ink 36c. Because the viscosity of the damming ink 36c is higher than that of the base ink 36b, the damming ink 36c is less likely to flow when it lands on the transfer medium M1 bearing the image IM1. This further strengthens the damming structure DM1, further suppressing the flow of the base ink layer UC1.

[0044] Next, a method of printing on the transfer medium M2 will be described with reference to Figures 5 to 9. The printing method shown in Figure 5 includes the following steps. (c1) A first step ST1 in which the colored ink 36a is ejected from the print head 30 to form an image IM1 on the transfer medium M1. (c2) A second process ST2 in which the damming ink 36c is ejected from the print head 30 to form a damming structure DM1 in contact with at least a part of the image IM1 on the transfer medium M1 carrying the image IM1. (c3) A third process ST3 in which the base ink 36b is ejected from the print head 30 to form a base ink layer UC1 on the transfer medium M1 having the image IM1 and the damming structure DM1. (c4) An adhesive application step ST4 in which an adhesive 111 is applied to the transfer medium M1 having the base ink layer UC1. (c5) A heating step ST5 in which the transfer medium M1 to which the adhesive 111 has been applied is heated. (c6) A transfer step ST6 in which the image IM1 is transferred onto the transfer medium M2 by applying the adhesive 111 to the transfer medium M2. The control unit 10 performs a first control for carrying out a first step ST1, a second control for carrying out a second step ST2, and a third control for carrying out a third step ST3.

[0045] For example, as shown in FIG. 2, assume that the drive unit 50 performs main scans on a band-by-band basis within the processing unit area A0, and performs sub-scans between main scans to cause the print head 30 to eject ink 36 into the processing unit area A0. Also, assume that color ink 36a ejected from the color ink head 31 lands on each band during the first main scan, blocking ink 36c ejected from the blocking ink head 40 lands on each band during the second main scan, and base ink 36b ejected from the base ink head 32 lands on each band during the third main scan. In this case, the first step ST1 is performed during the first main scan, the second step ST2 is performed during the second main scan, and the third step ST3 is performed during the third main scan. If the first main scan is a main scan in the forward direction D11, the second main scan may be a main scan in the backward direction D12 as in bidirectional printing, or a main scan in the forward direction D11 as in unidirectional printing. For each band, an image IM1 may be formed in one pass, a damming structure DM1 may be formed in one pass, a base ink layer UC1 may be formed in one pass, an image IM1 may be formed in multiple passes, a damming structure DM1 may be formed in multiple passes, or a base ink layer UC1 may be formed in multiple passes.

[0046] The control unit 10 may start forming the damming structure DM1 after completing the formation of the image IM1 over the entire processing unit area A0. That is, the control unit 10 may start forming the damming structure DM1 under the second control after completing the formation of the image IM1 under the first control. In this case, as the image IM1 that has been formed is dried, the damming structure DM1 becomes stronger, further suppressing the flow of the base ink layer UC1. Alternatively, the control unit 10 may start forming the base ink layer UC1 after completing the formation of the damming structure DM1 over the entire processing unit area A0. That is, the control unit 10 may start forming the base ink layer UC1 over the third control after completing the formation of the damming structure DM1 over the entire processing unit area A0. In this case, the damming structure DM1, once formed, dries, further strengthening the damming structure DM1 and further suppressing the flow of the base ink layer UC1. Taking into account the drying time of the damming structure DM1, the control unit 10 may start forming the base ink layer UC1 a predetermined time after completing the formation of the damming structure DM1 over the entire processing unit area A0. In this case, the damming structure DM1 dries over a certain period of time, further strengthening the damming structure DM1 and further suppressing the flow of the base ink layer UC1.

[0047] In the example shown in FIG. 1, a transfer medium M1 having an image IM1, a damming structure DM1, and a base ink layer UC1 is intermittently transported from the printer 2 to the adhesive applicator 100, tilted downward, and then entered the adhesive tank 110. At this time, the damming structure DM1 blocks at least a portion of the flow of the wet base ink layer UC1. If the adhesive tank 110 contains powdered adhesive 111, the adhesive 111 adheres to the wet base ink layer UC1. The adhesive tank 110 is an example of an adhesive applicator that applies the adhesive 111 to the transfer medium M1 having the base ink layer UC1. The transfer medium M1 sent from the conveyance unit 55 is then lowered, and the adhesive 111 is applied to it. FIG. 5 shows the state in which the image IM1, the damming structure DM1, the base ink layer UC1, and the powdered adhesive 111 are layered on the transfer medium M1 in the adhesive application step ST4. In this manner, the adhesive application step ST4 is performed. In the example shown in FIG. 1, a transfer medium M1 coated with a thermoplastic adhesive 111 is intermittently transported from an adhesive tank 110 to a heating unit 120. During this time, excess adhesive 111 is shaken off by tilting the transfer medium M1 again. Again, the damming structure DM1 blocks at least a portion of the flow of the wet base ink layer UC1. The heating unit 120 heats the transfer medium M1 coated with the adhesive 111. When the transfer medium M1 is heated to a temperature above the melting point of the adhesive 111, the adhesive 111 melts. FIG. 5 shows the state in which the image IM1, the damming structure DM1, the dried base ink layer UC1, and the molten adhesive 111 are layered in this order on the transfer medium M1 in the heating step ST5. If the thermal transfer device 200 is capable of heating the transfer medium M1, the heating unit 120 may preheat the transfer medium M1 to a temperature below the melting point of the adhesive 111. 1, the heated transfer medium M1 is intermittently discharged from the heating unit 120. The discharged transfer medium M1 is cut as necessary, placed on the transfer recipient medium M2 with the surface to which the adhesive 111 is applied facing the transfer recipient medium M2, and then carried into the thermal transfer device 200.

[0048] The thermal transfer device 200 pressurizes the transfer medium M1 and the transfer receiver medium M2 while the adhesive 111 applied to the transfer medium M1 contacts the transfer receiver medium M2. If the thermal transfer device 200 is equipped with a heating mechanism, the thermal transfer device 200 heats the transfer medium M1 and the transfer receiver medium M2 to a temperature equal to or higher than the melting temperature of the adhesive 111. Because the transfer medium M1 and the transfer receiver medium M2 are pressed by the thermal transfer device 200, the damming structure DM1 is not shown in FIG. 5. By pressing the transfer medium M1 and the transfer receiver medium M2, the image IM1 adheres to the transfer receiver medium M2 via the damming structure DM1, the base ink layer UC1, and the adhesive 111. In this manner, a transfer step ST6 is performed in which the image IM1 is transferred to the transfer receiver medium M2. When the transfer medium M1 is peeled off from the transfer receiver medium M2, the image IM1 remains on the transfer receiver medium M2, and the transfer receiver medium M2 to which the image IM1 has been transferred is obtained, as shown in FIG. 1. Because there is a layer of base ink 36b between the transferred image IM1 and the transfer medium M2, the color of the transfer medium M2 is prevented from affecting the image IM1, resulting in good image quality for the image IM1. The flow of the base ink layer UC1 is suppressed by the damming structure DM1, maintaining the quality of the image IM1 and suppressing deterioration in the quality of the transfer result. When the damming structure DM1 is formed from CL ink, the effect on the color of the image IM1 is suppressed.

[0049] Although the transfer medium M1 described above is continuous paper, it may also be cut sheets of paper. In this case, the user may place printed cut sheets of paper into the adhesive tank 110, thereby adhering powdered adhesive 111 to the base ink 36b. Although the transfer medium M1 tilts during this process, the flow of the base ink layer UC1 is suppressed by the damming structure DM1.

[0050] 6 and 7 schematically show an example of printing in which the range 302 of the damming structure DM1 is wider than the range 301 of the base ink layer UC1. Note that the cross-sectional view shown in Fig. 7, along with Figs. 9 and 15 described below, shows the height of each element in an exaggerated manner. The portion of the damming structure DM1 shown in Figs. 6 and 7 that is outside the range 301 of the base ink layer UC1 can be said to surround the entire periphery of the base ink layer UC1, and can also be said to outline the image IM1. In the first step ST1 shown in FIGS. 6 and 7, the control unit 10 performs a first control to form an image IM1 on the transfer medium M1 by causing the color ink heads 31 to eject color inks 36a based on the raster data for each of the C, M, Y, and K colors generated from the image data DA1. The formed image IM1 may be a collection of multiple individual images IM2 as shown in FIG. 6, or it may be a single image. If multiple individual images IM2 can be arranged in the processing unit area A0, multiple individual images IM2 are arranged in the processing unit area A0 to efficiently use the transfer medium M1. The number of individual images IM2 arranged in the processing unit area A0 depends on the size of the individual images IM2, and is therefore not limited to 16 as shown in FIG. 6.

[0051] In the second step ST2 shown in FIGS. 6 and 7, the control unit 10 performs a second control to form the damming structure DM1 based on the raster data of CL generated from the damming structure data DA2 derived from the image data DA1. The control unit 10 performs the second control to form the damming structure DM1, which contacts at least a portion of the image IM1, on the transfer medium M1 carrying the image IM1 by ejecting the damming ink 36c from the damming ink head 40. The damming structure DM1 shown in FIGS. 6 and 7 is lattice-shaped, with multiple partitions aligned along the first direction D1 and multiple partitions aligned along the second direction D2 intersecting each other, and has multiple rectangular openings OP1. Therefore, a portion of the image IM1 appears in the openings OP1. Because the base ink 36b is ejected onto the transfer medium M1 carrying the image IM1 and the damming structure DM1, the lattice-shaped damming structure DM1 can be said to divide the base ink layer UC1 into smaller portions.

[0052] The area 302 in which the damming structure DM1 is formed, as shown in FIGS. 6 and 7, is wider than the area 301 in which the base ink layer UC1 is formed. If the damming structure DM1 has an opening OP1, the area 302 in which the damming structure DM1 is formed refers to an area that includes the opening OP1. The control unit 10 determines the area 301 in which the base ink layer UC1 is formed based on, for example, the W dot data as the base data DA3, and then determines the area 302 in which the lattice-shaped damming structure DM1 is formed so that it is wider than the area 301 by a predetermined amount. The control unit 10 then generates damming structure data DA2 based on the determined areas 301 and 302 so that the protrusions TP1 of the damming structure DM1 are higher than the image IM1. For example, the control unit 10 controls the size of the dots formed by the colored ink 36a to be medium or smaller. In this case, the control unit 10 controls the size of the dots of the damming ink 36c to medium dots or smaller within the range 301 of the image IM1, i.e., the base ink layer UC1, and controls the size of the dots of the damming ink 36c to large dots outside the range 301 of the base ink layer UC1. The control unit 10 also controls the damming ink head 40 not to eject the damming ink 36c at the opening OP1 of the damming structure DM1. 6 and 7, the damming structure DM1 is on the image IM1, inside the formation area 301 of the image IM1. Outside the formation area 301 of the image IM1, the damming structure DM1 is in contact with the transfer medium M1. The damming structure DM1, which has one or more openings OP1, frames the image IM1, and the base ink 36b is ejected inside the frame, forming what can be described as a "reservoir" for the base ink 36b. The damming structure DM1 in the formation area 302, which is wider than the formation area 301 of the base ink layer UC1, suppresses the outflow of the base ink 36b, further suppressing the flow of the base ink layer UC1.

[0053] The lattice-shaped damming structure DM1 has protruding portions TP1 that intersect a virtual straight line LN1 along the transfer medium M1 and that passes through the image IM1 at three or more locations. When the transfer medium M1 is tilted so that its height changes between the upstream and downstream sides of the first direction D1 along the virtual straight line LN1, the protruding portions TP1 of the damming structure DM1 block the flow of the base ink layer UC1 at three or more locations. Blocking the flow at three or more locations means that protruding portions TP1 are formed in at least one location overlapping the base ink layer UC1 in addition to two locations around the base ink layer UC1, further suppressing the flow of the base ink layer UC1. When the first direction D1 is the transport direction from a position facing the print head 30 toward the adhesive tank 110, the damming structure DM1 can be said to have a structure in which the protruding portions TP1 intersect a virtual straight line LN1 along the transport direction at three or more locations. 1, when the transfer medium M1 is tilted so that its height changes between the upstream and downstream sides in the transport direction, the flow of the base ink layer UC1 is blocked at three or more locations where the convex portions TP1 intersect with the virtual straight line LN1 along the transport direction, thereby efficiently suppressing the flow of the base ink layer UC1.

[0054] Because the damming structure DM1 has one or more openings OP1, the ink consumption amount Q1 of the damming structure DM1 is less than the ink consumption amount Q2 of the base ink layer UC1. The ink consumption amount Q2 of the base ink layer UC1 refers to the total amount of base ink 36b used in the single connected base ink layer UC1, and the ink consumption amount Q1 of the damming structure DM1 refers to the total amount of damming ink 36c used in the area corresponding to the aforementioned "single connected base ink layer UC1." The ink consumption amount can be calculated from the number of ink droplets of a predetermined size ejected. If the ink droplet size is variable, for example, the ink consumption amount can be calculated by the number of ink droplets ejected converted to the predetermined size for forming large dots. The control unit 10 causes the damming ink head 40 to eject the damming ink 36c so that the amount of ink used Q1 is less than the amount of ink used Q2 of the base ink layer UC1, thereby forming a damming structure DM1 on the transfer medium M1 carrying the image IM1. This makes it easier for the damming ink 36c to dry, further strengthening the damming structure DM1 and further suppressing the flow of the base ink layer UC1.

[0055] 6 and 7, the control unit 10 performs a third control to form a base ink layer UC1 based on the W raster data derived from the image data DA1. The control unit 10 causes the base ink head 32 to eject the base ink 36b, thereby forming the base ink layer UC1 on the transfer medium M1 having the image IM1 and the damming structure DM1. The base ink layer UC1 is directly or indirectly superimposed on the image IM1, so that the image IM1 and the base ink layer UC1 are formed in the same area 301. If the damming structure DM1 has an opening OP1, the base ink layer UC1 is directly superimposed on the image IM1 at the opening OP1, and is superimposed on the damming structure DM1 at the portion where the damming ink 36c lands. 6 and 7, the convex portions TP1 of the blocking structure DM1 are present outside the base ink layer UC1, and therefore the flow of the base ink layer UC1 is blocked by the surrounding convex portions TP1.

[0056] 7, the powdered adhesive 111 adheres to at least the base ink layer UC1. If the damming structure DM1 still has wettability, the powdered adhesive 111 may adhere to the damming structure DM1. Note that if the damming ink 36c is a CL ink, even if the adhesive 111 does not adhere to the damming structure DM1, there is little effect on the color of the image IM1, so the quality of the image IM1 is maintained and degradation of the quality of the transfer result is suppressed.

[0057] Note that the damming structure DM1 is not limited to having multiple openings OP1, and may have a single opening OP1. For example, even if the damming structure DM1 is not on the image IM1 but exists only outside the range 301 of the image IM1, the base ink layer UC1 is dammed up by the damming structure DM1, and the quality of the image IM1 is maintained.

[0058] 8 and 9 schematically show an example of printing in which the range 302 of the damming structure DM1 is aligned with the range 301 of the base ink layer UC1. The lattice-shaped damming structure DM1 shown in Figures 8 and 9 can be said to surround the entire inner periphery of the base ink layer UC1, and can also be said to roughly outline the image IM1. In the first step ST1 shown in FIGS. 8 and 9, the control unit 10 performs the first control to form the image IM1 with the colored inks 36a on the transfer medium M1, as described above.

[0059] In the second step ST2 shown in FIGS. 8 and 9, the control unit 10 performs second control to form a damming structure DM1 using the damming ink 36c on the transfer medium M1 bearing the image IM1, so as to contact at least a portion of the image IM1, as described above. The area 302 in which the damming structure DM1 is formed shown in FIGS. 8 and 9 is the same as the area 301 in which the base ink layer UC1 is formed. The control unit 10 determines the formation area 301 of the base ink layer UC1 based on, for example, the W dot data as the base data DA3, and determines this area 301 as the formation area 302 of the lattice-shaped damming structure DM1. The control unit 10 then generates damming structure data DA2 based on the determined area 302. In the example shown in FIGS. 8 and 9, the damming structure DM1 is located on the image IM1. The lattice-shaped damming structure DM1 also has a structure in which the protrusions TP1 intersect the imaginary straight line LN1 along the transfer medium M1, which passes through the image IM1, at three or more locations. The imaginary straight line LN1 may be aligned with the first direction D1, which is the transport direction. As with the examples shown in Figures 6 and 7, the damming structure DM1 efficiently suppresses the flow of the base ink layer UC1. Furthermore, the ink usage amount Q1 of the damming structure DM1 is less than the ink usage amount Q2 of the base ink layer UC1. This facilitates drying of the damming ink 36c, further strengthening the damming structure DM1 and further suppressing the flow of the base ink layer UC1.

[0060] 8 and 9, the control unit 10 performs a third control to form a base ink layer UC1 using the base ink 36b on the transfer medium M1 having the image IM1 and the damming structure DM1, as described above. When the damming structure DM1 has an opening OP1, the base ink layer UC1 is directly superimposed on the image IM1 at the portion of the opening OP1, and is superimposed on the damming structure DM1 at the portion where the damming ink 36c has landed. In the adhesive application step ST4 shown in FIG. 9, the powder adhesive 111 is adhered to the base ink layer UC1.

[0061] The damming structure DM1 is not limited to having multiple openings OP1, and may have a single opening OP1. Even if the damming structure DM1 is formed over the entire surface of the image IM1, as long as the damming structure DM1 has an uneven shape with protrusions TP1, the base ink layer UC1 is dammed up by the damming structure DM1, and the quality of the image IM1 is maintained.

[0062] (3) Specific examples of printing device processing: 10 is a schematic diagram illustrating a print control process for controlling the formation of an image IM1, a damming structure DM1, and a base ink layer UC1 on a transfer medium M1. The control unit 10 shown in FIG. 4 starts the print control process when it receives a print instruction for the transfer medium M1 from the host device HO1 or the operation panel 24. When the print control process starts, the control unit 10 acquires image data DA1 representing the transfer medium M1 from the host device HO1 or the like (step S102). Hereinafter, the notation "step" may be omitted and the step code may be shown in parentheses.

[0063] After acquiring the image data DA1, the control unit 10 performs a color conversion process to convert the image data DA1 into ink volume data for the colored inks 36a and the base inks 36b (S104). If the image data DA1 is RGB data and the ink volume data is CMYKW data representing the amounts of the C, M, Y, K, and W inks 36 used, the control unit 10 references a color conversion LUT and converts the R, G, and B pixel values ​​into C, M, Y, K, and W pixel values. In the color conversion LUT, the W gradation value is set to a value that indicates the base ink 36b is used when at least one of the C, M, Y, and K colored inks 36a is used. This results in the base ink 36b being overlaid at the position of the image IM1. After the color conversion process, the control unit 10 performs a halftone process to generate dot data by reducing the number of gradations of the obtained ink volume data to, for example, two or four (S106). Dot data is generated for each of C, M, Y, K, and W, and includes W dot data as base data DA3.

[0064] After processing S106, the control unit 10 generates CL dot data as the damming structure data DA2 based on the base data DA3 (S108). For example, the control unit 10 determines the formation range 301 of the base ink layer UC1 based on the W dot data as the base data DA3, and then determines the formation range 302 of the damming structure DM1 based on the formation range 301. Here, as shown in FIGS. 6 and 7, the control unit 10 may determine the range 302 of the damming structure DM1 to be a predetermined amount wider than the range 301 of the base ink layer UC1, and generate the lattice-shaped damming structure data DA2 based on the determined ranges 301 and 302 so that the protrusions TP1 are higher than the image IM1. Alternatively, as shown in FIGS. 8 and 9, the control unit 10 may determine the range 301 of the base ink layer UC1 as the range 302 of the damming structure DM1 and generate the lattice-shaped damming structure data DA2.

[0065] After generating the damming structure data DA2, the control unit 10 performs a rasterization process to rearrange the dot data for each of C, M, Y, KW, and CL so that the image IM1, the damming structure DM1, and the base ink layer UC1 are formed in that order on the transfer medium M1 (S110). The generated raster data is data that first forms the image IM1 in the processing unit area A0, then forms the damming structure DM1 after the formation of the image IM1, and then forms the base ink layer UC1 after the formation of the damming structure DM1.

[0066] Finally, the control unit 10 generates a drive signal SG1 according to the raster data and sends it to the print head 30, and controls the printing unit 20 to first form an image IM1 in the processing unit area A0, form a damming structure DM1 after forming the image IM1, and form a base ink layer UC1 after forming the damming structure DM1 (S112). Thus, the control unit 10 performs a first control to form the image IM1 on the transfer medium M1, a second control to form the damming structure DM1 on the transfer medium M1 having the image IM1, and a third control to form a base ink layer UC1 on the transfer medium M1 having the image IM1 and the damming structure DM1. As a result, the image IM1 is first formed in the processing unit area A0, the damming structure DM1 is formed after the image IM1 is formed, and the base ink layer UC1 is formed after the damming structure DM1 is formed. By ejecting the damming ink 36c onto the transfer medium M1 bearing the image IM1 before the base ink 36b, the damming ink 36c dries faster, forming the damming structure DM1 with the protrusions TP1 that block at least a portion of the flow of the base ink layer UC1. This suppresses the flow of the base ink layer UC1, which requires wettability to adhere the adhesive 111, even if the transfer medium M1 is tilted or vibrated. This maintains the quality of the image IM1, and suppresses degradation of the transfer result quality.

[0067] (4) Variation: The present invention can be modified in various ways. For example, the entity that performs the above-described processing is not limited to a CPU, but may be an electronic component other than a CPU, such as an ASIC (Application Specific Integrated Circuit), etc. Of course, multiple CPUs may work together to perform the above-described processing, or a CPU and another electronic component (for example, an ASIC) may work together to perform the above-described processing. The host device HO1 may perform part of the print control process shown in Fig. 10. In this case, the control unit of the printing system SY1 is a combination of the control unit 10 in the narrow sense and the host device HO1. The color combination of the colored inks 36a is not limited to C, M, Y, and K, but may include orange, green, light cyan with a lower density than C, light magenta with a lower density than M, dark yellow with a higher density than Y, light black with a lower density than K, etc. Of course, the present invention is also applicable to cases where the colored inks 36a do not include some of the colors C, M, Y, and K.

[0068] The base ink 36b is not limited to W ink, but may be K ink containing a component that absorbs light, or gray ink containing a component that diffuses light and a component that absorbs light, or the like. The damming ink 36c may be the colored ink 36a used for the image IM1, etc. The control unit 10 can perform a second control to form a damming structure DM1 of the same color as the image IM1 on the transfer medium M1 carrying the image IM1 by causing the print head 30 to eject the colored ink 36a of the same color as the image IM1 as the damming ink 36c for each pixel.

[0069] The damming structure data corresponding to the damming ink 36c is not limited to dot data representing the state of dot formation of the ink 36 on a pixel-by-pixel basis, but may be ink volume data representing the amount of ink 36 used on a pixel-by-pixel basis. For example, the control unit 10 may determine the formation range 301 of the base ink layer UC1 based on the ink volume data for W as the base data, and then determine the formation range 302 of the damming structure DM1 based on the formation range 301. If the range 302 of the damming structure DM1 is wider than the range 301 of the base ink layer UC1 as shown in Figures 6 and 7, the control unit 10 may generate damming structure data DA2 representing the amount of damming ink 36c used on a pixel-by-pixel basis based on the determined ranges 301 and 302 so that the protrusions TP1 of the damming structure DM1 are higher than the image IM1. In this case, the control unit 10 may control the amount of damming ink 36c used within the range 301 of the image IM1, i.e., the base ink layer UC1, to, for example, 50%, and may control the amount of damming ink 36c used to, for example, 100% outside the range 301 of the base ink layer UC1. When the range 302 of the damming structure DM1 is matched to the range 301 of the base ink layer UC1 as shown in Figures 8 and 9, the control unit 10 may generate damming structure data DA2 that represents the amount of damming ink 36c used in pixel units based on the determined range 302.

[0070] The damming structure DM1 does not need to be present around the entire edge of the image IM1, but may be present only on a part of the edge of the image IM1, or may be present slightly inward from the edge of the image IM1. The convex portion TP1 of the blocking structure DM1 that divides the base ink layer UC1 into smaller portions is not limited to being one continuous portion, and may be divided into a plurality of portions.

[0071] FIG. 11 shows a schematic example of printing the protrusion TP1 of the damming structure DM1 by dividing it into a plurality of parts. In the first step ST1 shown in FIG. 11, the control unit 10 performs the first control to form the image IM1 with the colored inks 36a on the transfer medium M1, as described above.

[0072] In the second step ST2 shown in FIG. 11, the control unit 10 performs a second control to form a damming structure DM1 divided into multiple protrusions TP1 on the transfer medium M1 carrying the image IM1. Each protrusion TP1 is arranged on the image IM1 with its longitudinal direction facing the second direction D2. The damming structure DM1 shown in FIG. 11 also has a structure in which the protrusions TP1 intersect with an imaginary straight line LN1 that runs along the transfer medium M1 and passes through the image IM1 at three or more locations. The imaginary straight line LN1 may be aligned along the first direction D1, which is the transport direction. As in the examples shown in FIGS. 6 to 9, the damming structure DM1 efficiently suppresses the flow of the base ink layer UC1. In the third step ST3 shown in FIG. 11, the control unit 10 performs the third control to form a base ink layer UC1 using the base ink 36b on the transfer medium M1 having the image IM1 and the damming structure DM1, as described above.

[0073] 11, the damming ink 36c is ejected onto the transfer medium M1 having the image IM1 before the base ink 36b, which causes the damming ink 36c to dry and form a damming structure DM1. This suppresses the flow of the base ink layer UC1, which requires wettability to allow the adhesive 111 to adhere, even if the transfer medium M1 is tilted or vibrated.

[0074] As shown in FIG. 12, the damming structure DM1 may be arranged according to the shape of the base ink layer UC1. The image IM1 shown in FIG. 12 has an uneven shape with multiple protrusions PK1, resulting in the base ink layer UC1 also having an uneven shape with multiple protrusions PK1. When the transfer medium M1 having the base ink layer UC1 tilts, the base ink 36b, which still has fluidity, gathers around the protrusions PK1 and tends to drip from the protrusions PK1. Here, the area of ​​the blocking structure DM1 away from the protrusions PK1 is referred to as the first area A1, and the area that contacts or includes the protrusions PK1 is referred to as the second area A2. The protrusions TP1 of the blocking structure DM1 shown in FIG. 12 are not located in the first area A1 but are located in the second area A2 outside the image IM1, i.e., the base ink layer UC1. In the second step ST2, the control unit 10 performs a second control to form the protrusions TP1 in the second area A2, without forming the protrusions TP1 in the first area A1. In other words, in the second process ST2, the control unit 10 performs a second control to make the amount of blocking ink 36c per unit area required to form the convex portion TP1 in the second region A2 greater than the amount of blocking ink 36c per unit area required to form the convex portion TP1 in the first region A1.

[0075] In the above case, the convex portions TP1 present in the second region A2 where the base ink layer UC1 is likely to flow out effectively suppress the flow of the base ink layer UC1, so that deterioration in the quality of the transfer result can be further suppressed. Furthermore, the convex portions TP1 may be formed in the second region A2 to the extent that the amount of damming ink 36c per unit area in the first region A1 is less than the amount of damming ink 36c per unit area in the second region A2.

[0076] As an example of changing the amount of damming ink 36c per unit area, the control unit 10 may perform the second control to make the convex portions TP1 in the second region A2 larger than the convex portions TP1 in the first region A1. The control unit 10 may also perform the second control to make the number of convex portions TP1 in the second region A2 larger than the number of convex portions TP1 in the first region A1. Of course, the control unit 10 may also perform the second control to make the convex portions TP1 in the second region A2 larger than the convex portions TP1 in the first region A1 and to make the number of convex portions TP1 in the second region A2 larger than the convex portions TP1 in the first region A1.

[0077] As shown in FIG. 13, the damming structure DM1 may be arranged depending on the size of the base ink layer UC1. The transfer medium M1 shown in FIG. 13 has, as the image IM1, a first image IM11 and a second image IM12 that is larger than the first image IM11. The larger the image IM1, the more easily the base ink layer UC1 corresponding to the image IM1 flows out. Therefore, the amount of damming ink 36c per unit area required to form the convex portions TP1 in the region corresponding to the second image IM12 is set to be greater than the amount of damming ink 36c per unit area required to form the convex portions TP1 in the region corresponding to the first image IM11. In the second step ST2, the control unit 10 performs a second control to increase the amount of damming ink 36c per unit area required to form the convex portions TP1 in the region of the damming structure DM1 corresponding to the second image IM12 to be greater than the amount of damming ink 36c per unit area required to form the convex portions TP1 in the region of the damming structure DM1 corresponding to the first image IM11.

[0078] In the above case, the convex portion TP1 with a relatively large amount of ink present in the area corresponding to the second image IM12 where the base ink layer UC1 is prone to flow out effectively suppresses the flow of the base ink layer UC1, thereby further suppressing the deterioration of the quality of the transfer result. As an example of changing the amount of damming ink 36c per unit area, the control unit 10 may perform second control to make the convex portions TP1 in the region corresponding to the second image IM12 larger than the convex portions TP1 in the region corresponding to the first image IM11. The control unit 10 may also perform second control to make the number of convex portions TP1 in the region corresponding to the second image IM12 larger than the number of convex portions TP1 in the region corresponding to the first image IM11. Of course, the control unit 10 may also perform second control to make the convex portions TP1 in the region corresponding to the second image IM12 larger than the convex portions TP1 in the region corresponding to the first image IM11, and to make the number of convex portions TP1 in the region corresponding to the second image IM12 larger than the convex portions TP1 in the region corresponding to the first image IM11.

[0079] As shown in FIG. 14, the arrangement of the damming structure DM1 may be changed between the upstream region A3 and the downstream region A4. Here, the upstream region A3 is an example of a third region, and the downstream region A4 is an example of a fourth region. In FIG. 14, the region of the base ink layer UC1 corresponding to the image IM1 includes the upstream region A3 and the downstream region A4, which is downstream of the upstream region A3 in the first direction D1, which is the transport direction. As shown in FIGS. 1 and 4, when adhesive is applied to the transfer medium M1 after the transfer medium M1 sent from the transport section 55 descends, the base ink layer UC1 tends to flow downstream. Therefore, the amount of damming ink 36c per unit area required to form the protrusions TP1 in the downstream region A4 is set to be greater than the amount of damming ink 36c per unit area required to form the protrusions TP1 in the upstream region A3. In the second process ST2, the control unit 10 performs a second control to make the amount of blocking ink 36c per unit area required to form the convex portion TP1 in the downstream region A4 greater than the amount of blocking ink 36c per unit area required to form the convex portion TP1 in the upstream region A3.

[0080] In the above case, the convex portion TP1 with a relatively large amount of ink present in the downstream region A4 where the base ink layer UC1 is likely to flow out effectively suppresses the flow of the base ink layer UC1, thereby further suppressing deterioration in the quality of the transfer result. As an example of changing the amount of damming ink 36c per unit area, the control unit 10 may perform the second control to make the convex portions TP1 in the downstream region A4 larger than the convex portions TP1 in the upstream region A3. The control unit 10 may also perform the second control to make the number of convex portions TP1 in the downstream region A4 larger than the number of convex portions TP1 in the upstream region A3. Of course, the control unit 10 may also perform the second control to make the convex portions TP1 in the downstream region A4 larger than the convex portions TP1 in the upstream region A3 and to make the number of convex portions TP1 in the downstream region A4 larger than the number of convex portions TP1 in the upstream region A3.

[0081] As shown in FIG. 15, printing may be performed so that the damming structure DM1 fits into the hole H1 in the image IM1. 15 has a hole H1. The control unit 10 generates raster data for the colored inks 36a based on image data DA1 that represents the image IM1 having the hole H1. In a first step ST1, the control unit 10 performs a first control to form the image IM1 having the hole H1 on the transfer medium M1 based on the raster data.

[0082] As described above, the control unit 10 determines the formation area 301 of the base ink layer UC1 based on the W dot data as the base data DA3, and then determines the formation area 302 of the damming structure DM1 based on the formation area 301. Additionally, the control unit 10 identifies the position of the hole H1 based on the image data DA1. In the second step ST2, the control unit 10 performs second control to generate the damming structure data DA2 so that a protrusion TP1 at the position of the hole H1 is formed that is at least higher than the image IM1. For example, the control unit 10 controls the size of the dots formed by the colored ink 36a to be medium dots or smaller. In this case, the control unit 10 controls the size of the dots formed by the damming ink 36c at the position of the hole H1 to be large dots. The protrusion TP1 formed at the position of the hole H1 functions as a stake that penetrates the image IM1 in the height direction, suppressing the flow of the base ink layer UC1.

[0083] In the third step ST3, the control unit 10 performs third control to form a base ink layer UC1 using the base ink 36b on the transfer medium M1 having the image IM1 and the damming structure DM1, as described above. In the adhesive application step ST4, the powdery adhesive 111 adheres to the base ink layer UC1. In the example shown in FIG. 15, the stake-like convex portion TP1 penetrating the image IM1 within the range 301 of the base ink layer UC1 suppresses the flow of the base ink layer UC1, further suppressing the deterioration of the quality of the transfer result.

[0084] (5) Conclusion: As described above, the present invention can provide various configurations that can suppress deterioration in the quality of the transfer result. Of course, even in an embodiment that consists only of the elements of the independent claims, the basic functions and effects described above can be obtained. Furthermore, it is possible to implement configurations in which the components disclosed in the above examples are substituted with each other or the combination is changed, or configurations in which the components disclosed in the publicly known techniques and the above examples are substituted with each other or the combination is changed, etc. The present invention also includes these configurations. [Explanation of symbols]

[0085] 1...printing device, 2...printer, 10...controller, 20...printing unit, 30...print head, 31...colored ink head, 32...base ink head, 33...carriage, 34...nozzle, 36...ink, 36a...colored ink, 36b...base ink, 36c...damming ink, 37...ink droplets, 40...damming ink head, 50...driver, 100...adhesive applying device, 110...adhesive tank, 111...adhesive, 120...heating unit, 200...thermal transfer device, 301, 302...range, A0...processing unit area, A1...first area, A2...second area, A3...upstream area, A4...downstream area, D1...first direction, D2...second direction, D11...forward direction, D12...returning direction, DA1...image data, DA2...damming structure data, DA3...base data, DM1...damming structure, H1...hole, IM1...image, IM2...individual image, IM11...first image, IM12...second image, LN1...virtual straight line, M1...transfer medium, M2...transfer receiving medium, OP1...opening, PK1...protrusion, Q1, Q2...amount of ink used, ST1...first process, ST2...second process, ST3...third process, ST4...adhesive application process, ST5...heating process, ST6...transfer process, SY1...printing system, TP1...protrusion, UC1...base ink layer.

Claims

1. A printing system that forms an image to be transferred to a transfer medium and a base ink layer to which an adhesive is attached on a transfer medium, comprising: a print head capable of ejecting a plurality of types of ink capable of forming the image, the base ink layer, and a damming structure having a protrusion that dams at least a portion of the flow of the base ink layer; a drive unit that changes the relative positional relationship between the print head and the transfer medium; a control unit that controls the ejection of the ink from the print head and the drive unit, Among the plurality of types of ink, the ink for forming the image is referred to as an image forming ink, the ink for forming the base ink layer is referred to as a base ink, and the ink for forming the damming structure is referred to as a damming ink, The control unit a first control for forming the image on the transfer medium by ejecting the image forming ink from the print head; a second control for forming the damming structure on the transfer medium having the image thereon by ejecting the damming ink from the print head, the damming structure being in contact with at least a portion of the image; a third control for forming the base ink layer on the transfer medium having the image and the damming structure by ejecting the base ink from the print head; A printing system that does this.

2. The printing system according to claim 1 , wherein the control unit starts forming the base ink layer in the third control after completing the formation of the damming structure in the second control.

3. 3. The printing system according to claim 1, wherein the blocking ink is a clear ink that does not contain a coloring material.

4. The printing system according to claim 1 , wherein the area in which the damming structure is formed is larger than the area in which the base ink layer is formed.

5. 3. The printing system according to claim 1, wherein the damming ink has a higher viscosity than the base ink.

6. 3. The printing system according to claim 1, wherein the control unit, in the second control, causes the print head to eject the damming ink so that the amount of ink used is less than the amount of ink used in the base ink layer, thereby forming the damming structure on the transfer medium having the image.

7. 3. The printing system according to claim 1, wherein the damming structure is a structure in which the convex portions intersect with an imaginary straight line along the transfer medium and passing through the image at three or more points.

8. an adhesive applying unit that applies the adhesive to the transfer medium having the base ink layer; the drive unit includes a transport unit that transports the transfer medium having the base ink layer from a position facing the print head in a transport direction toward the adhesive application unit, The printing system according to claim 7 , wherein the damming structure is a structure in which the convex portions intersect the virtual straight line along the transport direction at three or more points.

9. the region of the damming structure includes a first region and a second region through which the base ink layer flows more easily than the first region due to a shape of the base ink layer; 3. The printing system according to claim 1, wherein the control unit, in the second control, makes the amount of the damming ink per unit area required to form the convex portion in the second region greater than the amount of the damming ink per unit area required to form the convex portion in the first region.

10. the images include a first image and a second image that is larger than the first image; 3. The printing system according to claim 1, wherein the control unit, in the second control, increases the amount of the damming ink per unit area required to form the convex portions in the region of the damming structure corresponding to the second image to be greater than the amount of the damming ink per unit area required to form the convex portions in the region of the damming structure corresponding to the first image.

11. an adhesive applying unit that applies the adhesive to the transfer medium having the base ink layer; the drive unit includes a transport unit that transports the transfer medium having the base ink layer from a position facing the print head in a transport direction toward the adhesive application unit, The transfer medium sent out from the transport unit is lowered and then the adhesive is applied thereto. the region of the base ink layer corresponding to the image includes a third region and a fourth region located downstream of the third region in the transport direction, 3. The printing system according to claim 1, wherein the control unit, in the second control, makes the amount of the damming ink per unit area required to form the convex portion in the fourth region greater than the amount of the damming ink per unit area required to form the convex portion in the third region.

12. A printing method in which a relative positional relationship between a print head and a transfer medium is changed to form an image to be transferred to a transfer medium and an undercoat ink layer to which an adhesive is to be attached on the transfer medium, the method comprising: the print head is capable of ejecting a plurality of types of ink capable of forming the image, the base ink layer, and a damming structure having a protrusion that dams at least a portion of the flow of the base ink layer; Among the plurality of types of ink, the ink for forming the image is referred to as an image forming ink, the ink for forming the base ink layer is referred to as a base ink, and the ink for forming the damming structure is referred to as a damming ink, The printing method includes: a first step of forming the image on the transfer medium by ejecting the image forming ink from the print head; a second step of ejecting the damming ink from the print head to form the damming structure on the transfer medium having the image thereon, the damming structure being in contact with at least a portion of the image; a third step of ejecting the base ink from the print head to form the base ink layer on the transfer medium having the image and the damming structure; A printing method including:

Images