Printing system, printing method, and mixed powder

Abstract

Provided are a printing system, a printing method, and mixed powder that eliminate the need for a use of a liquid white ink.　A printing system 100 forms, on a transfer film F, an image to be transferred to a transfer target medium M1, and includes: an inkjet head 11 having a first nozzle 12a for discharging color ink onto a first image region A1 of the transfer film F to form the image; and a powder application device 103 for applying white powder and adhesive powder onto the color ink discharged onto the first image region A1.

Description

Printing system, printing method and mixed powder

[0001] The present disclosure relates to a printing system, a printing method, and a powder mixture that form an image on a transfer film to be transferred to a transfer medium.

[0002] For example, Patent Document 1 listed below describes a conventional technique using a printing device having an inkjet head for color inks and an inkjet head for white ink. According to this conventional technique, color inks are ejected onto a transfer medium to form an image consisting of a color ink layer, and white ink is ejected onto the color ink layer to form a base consisting of a white ink layer. Furthermore, hot-melt resin powder is applied onto the base, which is then melted and solidified to form a transfer sheet. The transfer sheet is then placed on a transfer medium and heated and pressurized, thereby transferring the base and image from the transfer sheet to the transfer medium.

[0003] JP 2023-87372 A

[0004] In the above-described conventional technology, the presence of a base between the image and the receiving medium reduces the influence of the color of the receiving medium on the image. However, the white ink forming the base may be more susceptible to pigment settling or drying than color inks. In contrast, attempts to prevent the settling or drying of white ink pigments could result in one of several effects: increased costs for the printing device, higher running costs due to the need for maintenance, or reduced productivity due to reduced printing time.

[0005] Therefore, an object of the present disclosure is to provide a printing system, a printing method, and a mixed powder that can reduce the above-mentioned effects.

[0006] The printing system according to the present disclosure is a system for forming an image on a transfer film to be transferred to a receiving medium, and includes an inkjet head having a first nozzle for ejecting color ink onto a first image area of ​​the transfer film to form the image, and a powder deposition unit for depositing white powder and adhesive powder onto the color ink ejected onto the first image area.

[0007] The printing method disclosed herein is a method for forming an image on a transfer film to be transferred to a receiving medium, and includes an image forming process for ejecting color ink from an inkjet head onto a first image area of ​​the transfer film to form the image, and a powder deposition process for depositing white powder and adhesive powder onto the color ink ejected onto the first image area.

[0008] The mixed powder according to the present disclosure is a powder that is attached to an image to be transferred to a transfer medium, and comprises a white powder that is attached onto color ink ejected from an inkjet head onto a transfer film, and an adhesive powder that adheres the white powder to the transfer medium.

[0009] According to the present disclosure, it is possible to provide a printing system, printing method, and mixed powder that do not require the use of liquid white ink, thereby reducing the effects of using liquid white ink, such as increased costs for the printing device, increased running costs, or reduced productivity.

[0010] FIG. 1 is a block diagram illustrating the configuration and functions of a printing system 100. FIG. 2 is a schematic diagram of a printing device 102 used in the printing system 100. FIGS. 3A and 3B are schematic diagrams illustrating examples of white powder and adhesive powder. FIG. 4 is a flowchart illustrating an example of the operation of the printing system 100. FIGS. 5A to 5C are schematic diagrams illustrating layers formed on a transfer film when the printing system 100 operates according to the flowchart of FIG. 4. FIG. 6 is a schematic diagram illustrating the configuration of a printing device 102A used in the printing system 100. FIGS. 7A to 7C are schematic diagrams illustrating layers formed on a transfer film when the printing system 100 including the printing device 102A performs an image formation process and a powder deposition process. FIG. 8 is a schematic diagram illustrating the configuration of a printing device 102B used in the printing system 100. 9A to 9C are schematic diagrams illustrating layers formed on a print medium when an image is formed directly on the print medium by a printing system 100 including a printing device 102B.

[0011] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Note that, in the following, identical or corresponding elements throughout the drawings will be designated by the same reference numerals, and redundant explanations will be omitted.

[0012] 1 is a block diagram showing a schematic configuration and functions of a printing system 100. This printing system 100 forms an image on a transfer medium M1, such as a towel, clothing, or bag, by transferring an image printed on a transfer film F to the transfer medium M1. To this end, the printing system 100 includes a print data generation device 101, a printing device 102, a powder deposition device 103, and a thermal transfer device 104.

[0013] The printing system 100 according to the present disclosure includes the printing device 102 and the powder deposition device 103 as essential components, but the print data generation device 101 and / or the thermal transfer device 104 may be included as optional components. While the devices 101 to 104 are illustrated in FIG. 1 as independent devices, some or all of them may be integrated into a single device. For example, the printing device 102 and the powder deposition device 103 may be configured as a single device.

[0014] The print data generating device 101 generates print data relating to an image to be printed on a transfer film F by the printing device 102 based on arbitrary image data. For example, the print data generating device 101 performs various processes on the image data to be used, such as a resolution conversion process that converts the resolution to match the specifications of the printing device 102, a color conversion process that converts color data to match the specifications of the printing device 102, and a halftone process that reproduces the gradation of the image data, to generate the print data.

[0015] The image data used in the print data generating device 101 may be generated by the print data generating device 101 itself, or may be input from an external device to the print data generating device 101. The print data generating device 101 also has a communication interface, and transmits the generated print data to the printing device 102 via this communication interface via a wired or wireless connection.

[0016] The printing device 102 is equipped with a communication interface and receives print data transmitted from the print data generating device 101. The printing device 102 is an inkjet printing device that ejects droplets of color ink or the like from an inkjet head 11. The printing device 102 then executes an "image forming process" in which ink is ejected onto the surface of the transfer film F based on this print data to form an image.

[0017] The transfer film F used in the printing system 100 of the present disclosure is made of a roll film, which is a long film of several meters or more wound into a roll. Then, the transfer film F pulled out from the roll film is successively subjected to printing of an image by the printing device 102 and application of powder by the powder application device 103. However, the configuration of the transfer film F is not limited to this. For example, a cut film cut to a predetermined size, such as A4 size or A3 size, can also be used as the transfer film F.

[0018] The printing device 102 will be described in further detail. FIG. 2 is a schematic diagram of the printing device 102. The printing device 102 is, for example, a serial head type printing device, and alternates between a process of forming an image by ejecting multiple types of ink while the inkjet head 11 moves and a process of transporting the transfer film F. Hereinafter, the transport direction of the transfer film F will be referred to as the front-rear direction. Of the two directions perpendicular to the front-rear direction, the direction in which the inkjet head 11 moves will be referred to as the left-right direction, and the remaining direction will be referred to as the up-down direction. However, the arrangement direction of the printing device 102 is not limited to this.

[0019] The inkjet head 11 provided in the printing device 102 is housed in the housing 10 of the printing device 102 and has a nozzle row in which a plurality of first nozzles 12a that open downward are aligned in the front-to-rear direction for ejecting ink. The printing device 102 of the present disclosure has a plurality of nozzle rows, and the inkjet head 11 has at least one nozzle row formed for each ink color, for example.

[0020] The inkjet head 11 is provided with a drive element for each first nozzle 12a. The drive element is a piezoelectric element, a heat generating element, an electrostatic actuator, or the like, and when driven, applies pressure to the ink in the inkjet head 11 to eject ink from the corresponding first nozzle 12a. Note that the first nozzles 12a shown in Fig. 2 are nozzles that eject at least color inks (including black ink). That is, the first nozzles 12a included in each nozzle row eject ink of the color corresponding to that nozzle row, for example, out of four colors, cyan, yellow, magenta, and black.

[0021] The printing device 102 includes a platen 13 disposed opposite the inkjet head 11. The platen 13 is positioned below the inkjet head 11 at a predetermined distance, and supports the transfer film F (or the print medium M2 described below) from below with its flat upper surface.

[0022] The printing device 102 is equipped with a transport device 14 that transports the transfer film F on the platen 13. The transport device 14 has, for example, two transport rollers 15 and a transport motor. The two transport rollers 15 are arranged at a distance from each other in the front and rear with the platen 13 sandwiched between them, and are connected to the rotating shaft of the transport motor via a reducer. Therefore, when the transport motor is driven, the two transport rollers 15 rotate about their axes, transporting the transfer film F on the platen 13 in the front-to-rear direction. Note that the printing device 102 may be equipped with a mechanism that moves the platen 13 itself, instead of the two transport rollers 15. In this case, the transfer film F is supported by the platen 13 and transported together with the platen 13.

[0023] The printing device 102 is equipped with a scanning device 16 that moves the inkjet head 11 in the left-right direction. The scanning device 16 has a carriage 17, two guide rails 18, an endless belt 19, and a scanning motor. The carriage 17 is a housing that supports the inkjet head 11. The two guide rails 18 extend left and right across the platen 13, and are arranged spaced apart in the front and back with the inkjet head 11 sandwiched between them. The two guide rails 18 support the carriage 17 so that it can move left and right.

[0024] The endless belt 19 is wound around two pulleys 20 provided near the left and right ends of one of the guide rails 18, and is connected to the carriage 17 at a predetermined location. The scanning motor has a rotating shaft connected to one of the left and right pulleys 20 via a reducer. Therefore, in this scanning device 16, when the scanning motor is driven to rotate, the endless belt 19 runs, and the carriage 17 supporting the inkjet head 11 moves left and right along the guide rails 18.

[0025] The printing device 102 includes a plurality of tanks 21a that store ink of each color to be supplied to the inkjet head 11. For example, the printing device 102 includes four tanks 21a that store ink of each color: cyan, yellow, magenta, and black. One end of a flexible tube 22 is connected to each tank 21a, and the other end of the tube 22 is connected to an ink supply port of the inkjet head 11. As a result, the ink in the tank 21a is sent to the inkjet head 11 through the tube 22.

[0026] Such a printing device 102 forms an image by ejecting color ink from the first nozzles 12a onto a first image area A1 (see FIG. 5A) on one main surface of a transfer film F supported on a platen 13. The transfer film F on which the image has been formed is transported from the printing device 102 and sent to the powder deposition device 103. The transport of the transfer film F from the printing device 102 to the powder deposition device 103 may be performed automatically by a transport device installed between the two devices, or may be achieved by manually picking up the transfer film F from the platen 13 and setting it in a predetermined position on the powder deposition device 103.

[0027] Note that the configuration of the printing device 102 shown in Fig. 2 is an example, and the configuration of the printing device 102 is not limited to that shown in Fig. 2. Also, while a serial head configuration has been exemplified here as the printing device 102, the configuration is not limited to this. For example, a line head configuration may be employed in which nozzles are arranged across the entire width of the printing area or more, and the head is fixedly arranged without moving (scanning).

[0028] The powder deposition device 103 performs a "powder deposition process" in which powder is deposited on the transfer film F on which an image has been formed and which has been conveyed from the printing device 102. For this purpose, the powder deposition device 103 includes, for example, a drum 30 that stores powder and through which the transfer film F is passed through the stored powder. In addition to this drum, the powder deposition device 103 may also include a rotating brush that removes excess powder from the powder deposited on the transfer film F, a heater that applies heat to the powder deposited on the transfer film F, and the like.

[0029] The powder stored in the drum 30 includes white powder and adhesive powder. The white powder is a powder that adheres to the color inks ejected from the inkjet head 11 and forms a base for the image to be transferred. The adhesive powder also serves to adhere the image formed with the color inks and the white powder to the transfer medium M1. Figures 3(A) and 3(B) are schematic diagrams showing examples of such white powder and adhesive powder.

[0030] The powder shown in Fig. 3(A) is a mixed powder P1 made by mixing a white powder and an adhesive powder. The white powder is a collection of white particles P11 containing, for example, titanium oxide (TiO2) as a coloring material that exhibits white color. The white particles P11 may be primary particles of titanium oxide crystals or agglomerated particles formed by aggregation of multiple particles of titanium oxide. Furthermore, the white particles P11 may contain other materials in addition to the coloring material such as titanium oxide.

[0031] The adhesive powder is a collection of adhesive particles P12, which are particles made of an adhesive that is solid at room temperature. For example, a hot-melt powder whose main component is a thermoplastic polymer that melts and exhibits adhesive properties when heated to a predetermined temperature can be used. Specifically, powders containing urethane particles, acrylic particles, polyester particles, polyamide particles, or mixtures of these can be suitably used as the adhesive powder. Furthermore, the color of the adhesive particles P12 is not particularly limited as long as they are white or transparent at least after thermal transfer to the transfer medium M1. The color before thermal transfer can be a color different from either white or transparent.

[0032] For example, the white particles P11 and adhesive particles P12 can be suitably used if they have the following relationship between specific gravity and average particle size: In other words, the specific gravity of the white particles P11 in the mixed powder P1 is greater than the specific gravity of the adhesive particles P12, and the average particle size of the white particles P11 is smaller than the average particle size of the adhesive particles P12. In this case, the weight of one white particle P11 can be made closer to the weight of one adhesive particle P12. This makes it possible to prevent uneven concentration due to the mixing of the white powder and adhesive powder in the mixed powder P1.

[0033] The method for determining the average particle size is not particularly limited. As an example, the particle size (median diameter when set to 50%) of the white particles P11 and the adhesive particles P12 can be used when measuring the passing mass percentage at the same percentage.

[0034] The powder shown in Figure 3(B) is a white adhesive powder P2, which is a collection of adhesive particles P21 containing a white coloring material P2a therein. In these adhesive particles P21, the coloring material P2a is entirely or at least partially coated with an adhesive P2b. Furthermore, as an example, the coloring material P2a may be fine particles made of the same material as the white particles P11 described with reference to Figure 3(A). Furthermore, as for the adhesive P2b, the same material as the adhesive particles P12 described with reference to Figure 3(A) may be used.

[0035] The adhesive particles P21 are white and exhibit adhesive properties at a predetermined temperature. Therefore, the white adhesive powder P2, which is a collection of the adhesive particles P21, forms both a white powder and an adhesive powder. When such white adhesive powder P2 is used, it is possible to reduce the occurrence of uneven density of the white colorant and adhesive in the white adhesive layer L2 (see FIG. 5C ), which will be described later. Note that, like the adhesive particles P12 in FIG. 3A , the color of the adhesive particles P21 only needs to be white or transparent at least after thermal transfer to the transfer medium M1, and there are no particular restrictions on the color before thermal transfer.

[0036] In the following, an example will be described in which the mixed powder P1 shown in Fig. 3(A) is used as the powder used in the powder deposition device 103, but the white adhesive powder P2 shown in Fig. 3(B) may also be used. Also, a powder obtained by mixing the mixed powder P1 and the white adhesive powder P2 may also be used.

[0037] The powder deposition device 103 according to the present disclosure deposits the above-described white powder and adhesive powder onto the transfer film F. Specifically, the transfer film F on which an image is formed in the first image area A1 is passed through the drum 30. As a result, the white powder and adhesive powder stored in the drum 30 are deposited onto the color inks ejected onto the first image area A1 on the transfer film F.

[0038] If the powder deposition device 103 is equipped with a rotating brush downstream of the drum 30, excess powder deposited on the ink can be removed by brushing the surface of the transfer film F. If the powder deposition device 103 is equipped with a heater downstream of the drum 30 or the rotating brush, it can heat the transfer film F. When the transfer film F is heated, the adhesive powder deposited on the ink in the first image area A1 melts, and the adhesive is fixed to the transfer film F together with the white powder.

[0039] The transfer film F on which the white powder and adhesive have been fixed is cooled to a degree that causes the molten adhesive to re-solidify, and then sent to the thermal transfer device 104 .

[0040] The thermal transfer device 104 transfers the image on the transfer film F, to which powder has been applied by the powder application device 103, onto the transfer recipient medium M1. For this purpose, the thermal transfer device 104 is equipped with a heat press machine 40. The heat press machine 40 has, for example, a lower iron 41, an upper iron 42, and a heater mounted within the upper iron 42. The transfer recipient medium M1 is placed on the lower iron 41, and the transfer film F is placed at a desired position on the transfer recipient medium M1. At this time, the transfer film F is placed with the main surface on which the first image region A1 is located facing downward (i.e., the main surface faces the transfer recipient medium M1).

[0041] In this state, the upper iron 42 descends, and the transfer medium M1 and the transfer film F are sandwiched between the lower iron 41 and the upper iron 42. The heater is then driven to heat the transfer medium M1 and the transfer film F. This melts the adhesive again, and the image on the transfer film F is transferred to the transfer medium M1. The heater may be heated in advance.

[0042] Next, a description will be given of the operation of the printing system 100. Fig. 4 is a flowchart showing an example of the operation of the printing system 100, and particularly shows the operation of the printing system 100 in the image formation process in the printing device 102 and the powder deposition process in the powder deposition device 103. Figs. 5(A) to 5(C) are schematic diagrams illustrating layers formed on the transfer film F when the printing system 100 operates according to the flowchart of Fig. 4.

[0043] As shown in Fig. 4, the printing device 102 ejects color inks from the first nozzles 12a of the inkjet head 11 based on print data to form an image on the transfer film F (step S1). Here, as shown in Figs. 5A and 5B, the area on one main surface of the transfer film F where the image is formed is referred to as a first image area A1. In this case, the printing device 102 forms an image by ejecting color inks into the first image area A1 of the transfer film F. In this way, the printing device 102 performs the "image forming process." Furthermore, by performing this process, a layered color ink layer L1 made of the ejected color inks is formed on the transfer film F, as shown in Fig. 5B.

[0044] Next, the powder deposition device 103 deposits white powder and adhesive powder onto the color inks ejected onto the first image area A1 on the transfer film F (step S2). That is, before the surface of the color ink layer L1 dries, the transfer film F is passed through the drum 30. This causes the white powder and adhesive powder to adhere onto the color ink layer L1 formed in the first image area A1. In this way, the powder deposition device 103 executes the "powder deposition process."

[0045] Furthermore, by carrying out this process, a white adhesive layer L2 made of a white coloring material and adhesive is formed on the color ink layer L1 as shown in Fig. 5(C). The white adhesive layer L2 is not formed anywhere other than on the color ink layer L1. Fig. 5(C) schematically illustrates the state in which the transfer film F is heated after the white powder and adhesive powder have been attached, melting the adhesive powder and fixing it to the transfer film F.

[0046] As can be seen from the above explanation, in the printing system 100 according to the present embodiment, the first nozzle 12a of the printing device 102 ejects color ink onto the transfer film F, and then the powder deposition device 103 deposits white powder and adhesive powder onto the color ink. As a result, a color ink layer L1 that forms an image is formed on the transfer film F, and a white adhesive layer L2 made of the white powder and adhesive powder is formed on this color ink layer L1. When these layers L1 and L2 are transferred to the transfer medium M1, an image is formed on the transfer medium M1 with the white adhesive layer L2 as a base.

[0047] In this way, according to the printing system 100 of this embodiment, it is not necessary to use liquid white ink to form the base of the image to be transferred onto the transfer medium M1, and therefore it is possible to reduce at least one of the effects, such as increased costs for the printing device, increased running costs, or reduced productivity, which would occur if liquid white ink were used.

[0048] Here, we will specifically describe the effect of white ink on the printing device 102. White ink is often composed of a liquid solvent containing a white colorant, such as titanium oxide, which has a high specific gravity. Such white ink is prone to settling of the colorant in the solvent inside the inkjet head, ink flow path, tank, cartridge, and other components of the printing device. Settling of the colorant causes unevenness in the distribution of the colorant in the solvent, resulting in unevenness in the solvent concentration and ink viscosity. This unevenness can lead to ink ejection problems in the inkjet head. Furthermore, settling of the colorant can result in the ejection of supernatant ink with a low colorant content during printing, which can lead to reduced image quality.

[0049] To date, those skilled in the art have taken the following measures to address these concerns: In other words, conventional printing devices have adopted methods such as periodically circulating the white ink in the white ink flow path to prevent the colorant from settling in the solvent, agitating the white ink with an agitator provided in the white ink tank, or having the user hold the tank and shake it to agitate the white ink.

[0050] Furthermore, in order to prevent ejection defects and degradation of image quality, conventional printing devices also employ methods of frequently performing various maintenance operations, such as wiping to clean the nozzle surface of the inkjet head, flushing to drive the inkjet head actuator to eject ink from the nozzles, and purging to apply positive or negative pressure to the nozzles using a pump to forcibly expel ink from the nozzles.

[0051] While such methods are effective in resolving the above concerns to a certain extent, they increase the cost of the printing device, increase running costs during printing, or reduce productivity during printing.In contrast, the printing system 100 does not require the use of liquid white ink, so it is possible to reduce at least one of the effects of increased cost of the printing device, increased running costs, or reduced productivity.

[0052] Next, we will explain another embodiment of the printing system 100. This printing system 100 includes a printing device 102A instead of the printing device 102 in Fig. 1. Furthermore, this printing system 100 forms the background of the image and also expresses the white parts in the image by using white powder that is applied to the transfer film F by a powder application device 103.

[0053] Figure 6 is a schematic diagram showing the configuration of a printing device 102A. The printing system 100 according to this embodiment includes the same print data generating device 101, powder deposition device 103, and thermal transfer device 104 as those described with reference to Figure 1, but includes a printing device 102A that is different from the printing device 102. That is, the printing device 102A shown in Figure 6 is mostly the same as the printing device 102 shown in Figure 2, but the configuration of the inkjet head is different. This point will be explained below.

[0054] As shown in FIG. 6, the printing device 102A includes an inkjet head 11A. This inkjet head 11A has second nozzles 12b in addition to the first nozzles 12a described with reference to FIG. 2. The second nozzles 12b are aligned in a row along the front-to-rear direction, and the row of second nozzles 12b is disposed to the side of and parallel to the row of first nozzles 12a. The second nozzles 12b eject the permeable liquid onto a second image region A2 (see FIG. 7B), which is a region on the transfer film F that is different from the first image region A1. The printing device 102A also includes a tank 21b that stores the permeable liquid and corresponds to the second nozzles 12b.

[0055] Note that the configuration of the printing device 102A shown in Fig. 6 is an example, and the configuration of the printing device 102A is not limited to that shown in Fig. 6. For example, in the inkjet head 11A, the nozzle row of the second nozzles 12b may be arranged in front of or behind the nozzle row of the first nozzles 12a. Furthermore, the inkjet head including the first nozzles 12a and the inkjet head including the second nozzles 12b may be configured to be separate from each other.

[0056] The permeable liquid ejected from the second nozzle 12b is typically a colorless, transparent liquid, and a solvent used to mix coloring materials in color inks can be used. However, the permeable liquid is not limited to this, and any liquid that is permeable enough to transmit at least the color of the white powder may be used. Therefore, the permeable liquid may be a liquid that contains a trace amount of coloring material or the like and has a slight color. Note that this permeable liquid is only required to be in a state that is permeable enough to transmit at least the color of the white powder after thermal transfer to the transfer medium M1. Therefore, the color prior to thermal transfer does not need to have the above-mentioned permeability, and is not particularly limited.

[0057] 7A to 7C are schematic diagrams illustrating layers formed on the transfer film F when the printing system 100 according to the present embodiment performs the image forming process and the powder deposition process. As shown in Fig. 7A, in addition to a first image area A1, a second image area A2 different from the first image area A1 is present on one main surface of the transfer film F.

[0058] Of these, the first image area A1 is an area onto which color ink is ejected from the first nozzles 12a by the printing device 102A based on print data. Therefore, as shown in FIG. 7B, a layered color ink layer L1 made of the deposited color ink is formed in this first image area A1. Furthermore, the second image area A2 is an area onto which permeable liquid is ejected from the second nozzles 12b by the printing device 102A based on print data. Then, as shown in FIG. 7B, a layered permeable liquid layer L3 made of the deposited permeable liquid is formed in this second image area A2.

[0059] The first image area A1 corresponds to the chromatic color portions other than white and the black portion of the image to be transferred, and the second image area A2 corresponds to the white portion of the image to be transferred.

[0060] After the color ink layer L1 and the permeable liquid layer L3 are formed on the transfer film F, the powder deposition device 103 deposits white powder and adhesive powder onto the transfer film F. That is, before the surfaces of the color ink layer L1 and the permeable liquid layer L3 dry, the transfer film F is passed through the drum 30. This causes the white powder and adhesive powder to adhere to the color ink layer L1 and the permeable liquid layer L3. As a result, as shown in FIG. 7C , a white adhesive layer L2 made of a white colorant and adhesive is formed on the color ink layer L1 and the permeable liquid layer L3. Note that FIG. 7C schematically illustrates the state in which the transfer film F is heated after the white powder and adhesive powder have been deposited, melting the adhesive powder and fixing it to the transfer film F.

[0061] Thereafter, the image on the transfer film F on which the layers L1 to L3 have been formed is transferred to a predetermined position on the transfer medium M1 as already described. In this way, an image is formed on the transfer medium M1.

[0062] Here, in the image transferred to the transfer medium M1, the portion corresponding to the permeable liquid layer L3 is visible through the underlying white adhesive layer L2. Therefore, the color of the white portions in the image can be expressed by the white color of the white powder. This not only eliminates the need for liquid white ink to form the image base, but also eliminates the need for liquid white ink to express the white regions in the image. Therefore, it is possible to reduce at least some of the multiple effects described above when using liquid white ink.

[0063] Next, we will explain yet another embodiment of the printing system 100. This printing system 100 includes a printing device 102B instead of the printing device 100 in Figure 1. This printing system 100 is also a system that can form an image by ejecting ink directly onto a printing medium M2 such as a towel, clothing, or bag, without performing transfer using a transfer film F.

[0064] Figure 8 is a schematic diagram showing the configuration of a printing device 102B. The printing system 100 according to this embodiment includes the same print data generating device 101, powder deposition device 103, and thermal transfer device 104 as those described with reference to Figure 1, but includes a printing device 102B that is different from the printing device 102. That is, the printing device 102B shown in Figure 8 is mostly the same as the printing device 102 shown in Figure 2, but the configuration of the inkjet head is different. This point will be explained below.

[0065] As shown in FIG. 8, the printing device 102B is equipped with an inkjet head 11B. This inkjet head 11B has a third nozzle 12c in addition to the first nozzle 12a described with reference to FIG. 2. A plurality of the third nozzles 12c are aligned in the front-to-rear direction to form a nozzle row, and the nozzle row of the third nozzles 12c is arranged to the side of and parallel to the nozzle row of the first nozzles 12a. This third nozzle 12c is a nozzle that ejects liquid white ink onto a third image region A3 (see FIG. 9A), which is an area on the printing medium M2. Note that the printing device 102B also has a tank 21c that stores liquid white ink and corresponds to this third nozzle 12c.

[0066] Note that the configuration of the printing device 102B shown in Fig. 8 is an example, and the configuration of the printing device 102B is not limited to that shown in Fig. 8. For example, in the inkjet head 11B, the nozzle row of the third nozzles 12c may be arranged in front of or behind the nozzle row of the first nozzles 12a. Furthermore, the inkjet head including the first nozzles 12a and the inkjet head including the third nozzles 12c may be configured to be separate from each other.

[0067] 9A to 9C are schematic diagrams illustrating layers formed on the print medium M2 when an image is formed directly on the print medium M2 using the printing system 100 according to this embodiment. As shown in FIG. 9A, a third image area A3 exists on the print medium M2. This third image area A3 is an area onto which white ink is ejected from the third nozzle 12c by the printing device 103B based on print data. Therefore, as shown in FIG. 9B, a layer-like white ink layer L4 made of the deposited white ink is formed in this third image area A3.

[0068] Furthermore, the printing device 102B forms an image by ejecting color inks from the first nozzles 12a onto the white ink ejected into the third image area A3, i.e., onto the white ink layer L4. Therefore, as shown in FIG. 9C , a color ink layer L5 made of color inks is formed on the white ink layer L4. This allows the printing device 102B to form an image with a white base directly on the printing medium M2. That is, the printing device 102B according to this embodiment has a configuration similar to that of the printing device 102 in FIG. 2, but also has a third nozzle 12c that ejects liquid white ink.

[0069] Therefore, the printing system 100 according to this embodiment can selectively use two printing methods: a method of forming an image on a transfer medium M1 using a transfer method that does not use liquid white ink (transfer printing method), and a method of forming an image by ejecting liquid white ink directly onto a print medium M2 (direct printing method).

[0070] 8, the printing device 102B is provided with an input device 25 that is configured with a liquid crystal touch panel display or the like and can be operated by the user. By operating this input device 25, the user can set the printing device 102B to execute printing using a selected one of the above-mentioned transfer printing method and direct printing method.

[0071] For example, if the user operates the input device 25 to select the transfer printing method, the printing system 100 executes the transfer printing method according to the procedure described with reference to Figures 4 and 5, or the procedure described with reference to Figure 7. Also, if the user operates the input device 25 to select the direct printing method (i.e., selects to form an image on the print medium M2 without forming it on the transfer film F), the printing system 100 executes the direct printing method according to the procedure described with reference to Figure 9. Note that the input means for selecting the printing method is not limited to the input device 25 provided in the printing device 102B. For example, the input means may be provided in a device other than the printing device 102B, such as the print data generation device 101 or another personal computer that can communicate with the printing device 102B.

[0072] The present disclosure is applicable to a printing system and printing method for transferring an image formed on a transfer film to a transfer medium, and a mixed powder that can be used in these systems and methods.

[0073] REFERENCE SIGNS LIST 11 Inkjet head 12a First nozzle 12b Second nozzle 12c Third nozzle 100 Printing system 102 Printing device 103 Powder deposition device A1 First image area A2 Second image area A3 Third image area F Transfer film M1 Transfer receiving medium P1 Mixed powder P2 White adhesive powder

Claims

1. A printing system that forms an image on a transfer film to be transferred to a receiving medium, comprising: an inkjet head having a first nozzle that ejects color ink onto a first image area of ​​the transfer film to form the image; and a powder deposition unit that deposits white powder and adhesive powder onto the color ink ejected onto the first image area.

2. The printing system described in claim 1, wherein the inkjet head has a second nozzle that ejects a transparent liquid that can transmit the color of the white powder onto a second image area on the transfer film that is different from the first image area, and the powder adhesion section adheres the white powder and the adhesive powder onto the transparent liquid ejected onto the second image area.

3. A printing system as described in claim 1, wherein the powder adhesion section adheres at least one of the following: a mixed powder obtained by mixing the white powder and the adhesive powder; and white adhesive powder which is a collection of adhesive particles containing white coloring material therein and which constitutes the white powder and also the adhesive powder.

4. The printing system according to claim 3, wherein the specific gravity of the particles constituting the white powder in the mixed powder is greater than the specific gravity of the particles constituting the adhesive powder, and the average particle size of the particles constituting the white powder is smaller than the average particle size of the particles constituting the adhesive powder.

5. The printing system described in claim 1, wherein the inkjet head has a third nozzle that ejects liquid white ink onto a third image area of ​​the printing medium, and when the image is formed on the printing medium without being formed on the transfer film, white ink is ejected from the third nozzle onto the third image area of ​​the printing medium, and color ink is ejected from the first nozzle onto the white ink ejected onto the third image area.

6. A printing method for forming an image on a transfer film to be transferred to a receiving medium, comprising: an image forming process for ejecting color ink from an inkjet head onto a first image area of ​​the transfer film to form the image; and a powder deposition process for depositing white powder and adhesive powder onto the color ink ejected onto the first image area.

7. A powder mixture to be attached to an image to be transferred to a transfer medium, the powder mixture comprising: a white powder that is attached on top of color inks ejected from an inkjet head onto a transfer film; and an adhesive powder that adheres the white powder to the transfer medium.

Images