Device for producing transfer printing sheet

Abstract

The present invention, in cases when a printing layer has been transferred to an object to be printed, inhibits the color of the object from being seen through. This device for producing a transfer printing sheet comprises a photosensitive drum, an exposure device, a developing device, a first transfer device, a fixing device, a film cartridge, and a second transfer device. The device for producing a transfer printing sheet produces a transfer printing sheet (PS) for transferring a printing layer to an object to be printed, with a viscoelastic layer interposed therebetween. The first transfer device transfers a toner on the photosensitive drum to a sheet (S). The film cartridge includes a film (PF) having a viscoelastic layer (PF3), a feed reel having the film (PF) wound thereon, and a winding-up reel for winding the film (PF) thereon. The second transfer device conveys both the sheet (S) on which a printing layer has been formed and the film (PF) in an overlapping state, and transfers the viscoelastic layer (PF3) to the printing layer. The viscoelastic layer (PF3) contains a white pigment.

Description

Transfer printing sheet producing apparatus

[0001] The present disclosure relates to a transfer printing sheet producing apparatus for producing a transfer printing sheet.

[0002] Patent Document 1 discloses a layer transfer apparatus. The layer transfer apparatus superimposes a second sheet having an adhesive layer on a first sheet on which a print layer has been formed by an image forming apparatus, conveys, heats and pressurizes the superimposed sheets, and thermally transfers the adhesive layer to the print layer. A sheet having the adhesive layer transferred to the print layer can be used to print the print layer on a fabric such as a T-shirt, for example.

[0003] Japanese Unexamined Patent Application Publication No. 2019-059086

[0004] Incidentally, when a sheet having a viscoelastic layer transferred to a print layer is produced and the print layer is printed on an object such as a fabric like a T-shirt, if the object is a dark color, there has been a problem that the color of the object shows through.

[0005] Therefore, an object of the present disclosure is to suppress the color of an object from showing through when a print layer is transferred to the object.

[0006] A transfer printing sheet producing apparatus for achieving the above-described problem includes a photosensitive drum, an exposure device, a developing device, a first transfer device, a fixing device, a film cartridge, and a second transfer device. The transfer printing sheet producing apparatus produces a transfer printing sheet for transferring a print layer onto an object via a viscoelastic layer. In the transfer printing sheet, a sheet, a print layer, and a viscoelastic layer are stacked in this order. The exposure device exposes the photosensitive drum. The developing device supplies toner to the photosensitive drum. The first transfer device transfers the toner supplied onto the photosensitive drum to the sheet, and forms the print layer on the sheet. The fixing device fixes the print layer to the sheet. The film cartridge includes a film having a viscoelastic layer, a supply reel around which the film is wound, and a take-up reel that takes up the film. The second transfer device conveys the sheet with the print layer formed thereon and the film in a superimposed state, and transfers the viscoelastic layer onto the print layer. The viscoelastic layer contains a white pigment.

[0007] By including a white pigment in the viscoelastic layer that transfers the printed layer to the object, it is possible to suppress the transparency of the object's color when the printed layer is transferred to the object.

[0008] Furthermore, the white pigment contained in the viscoelastic layer may also contain titanium dioxide.

[0009] Because the white pigment contained in the viscoelastic layer contains titanium dioxide, it can suppress the transparency of the object's color.

[0010] Furthermore, multiple developing units may be provided, and the developing unit that supplies the toner for the printing layer closest to the viscoelastic layer may be configured to supply toner containing white pigment.

[0011] By layering a viscoelastic layer containing white pigment onto a toner containing white pigment, the transparency of the object's color can be further suppressed.

[0012] Furthermore, the white pigment contained in the toner may also contain titanium dioxide.

[0013] Because the white pigment in the toner contains titanium dioxide, it can suppress the transparency of the color of the object being torn.

[0014] Furthermore, the opacity of the viscoelastic layer may be greater than the opacity of the printed layer with solid toner containing white pigment.

[0015] Furthermore, among the multiple developing units, the developing units other than the one that supplies toner containing white pigment may include a developing unit that supplies yellow toner, a developing unit that supplies magenta toner, and a developing unit that supplies cyan toner.

[0016] Developers other than those that supply toner containing white pigment have developers that supply yellow, magenta, and cyan toners. Therefore, full-color images can be formed, and black images can be formed by layering yellow, magenta, and cyan.

[0017] Furthermore, the first transfer device may have an endless belt that faces the photosensitive drum and transports the sheet. The transfer printing sheet creation device may be configured to form a first toner image on the sheet transported on the belt using yellow, magenta, and cyan toners, and then form a second toner image on top of the first toner image using toner containing white pigment.

[0018] The system may also include a control unit. The control unit may determine whether or not to form a toner image containing white pigment in each predetermined range. The control unit may be configured to form a second toner image formed with toner containing white pigment in the predetermined range if the area occupancy rate of the toner image formed from yellow, magenta, and cyan toners in the predetermined range is less than a threshold, and not form a second toner image in the predetermined range if the area occupancy rate is equal to or greater than the threshold.

[0019] Furthermore, the predetermined range may be a range corresponding to the dither matrix.

[0020] Furthermore, multiple developing units may be provided, and the developing unit that supplies the toner for the printing layer closest to the viscoelastic layer may contain transparent toner.

[0021] The developer unit that supplies the toner for the printing layer closest to the viscoelastic layer contains transparent toner. Therefore, the viscoelastic layer containing white pigment is transferred to the areas where the image is formed with the transparent toner. As a result, the viscoelastic layer containing white pigment can be transferred to any part of the sheet.

[0022] According to this disclosure, when a printed layer is transferred to an object, it is possible to suppress the transparency of the object's color.

[0023] This figure shows a transfer printing sheet creation apparatus according to an embodiment. This figure shows an image forming apparatus. This figure shows an image forming apparatus with the drawer pulled out. Figure (a) shows the separation mechanism and Figure (b) shows the connection of the control unit, motor, clutch and agitator. This figure shows a layer transfer apparatus. Figure (a) shows the bias applied during image formation and Figures (b) and (c) show the bias applied during ejection control. This is a cross-sectional view (a) showing a sheet and film on which a printed layer has been formed, a cross-sectional view (b) showing the state in which the film is pressed against the sheet, and a cross-sectional view (c) showing the state in which the base layer of the film is peeled off from the sheet. This is a cross-sectional view (a) showing the state in which the transfer printing sheet and the fabric are pressed against each other, and a cross-sectional view (b) showing the state after the transfer printing sheet has been peeled off the fabric on which the printed layer has been transferred. This is a transfer printing sheet on which a mirror image of the toner image has been formed, Figure (b) showing the state in which the transfer printing sheet is placed on the fabric and partially peeled off, and Figure (c) showing the fabric with the toner image transferred. Figures (a) and (b) compare the case where white toner is not image-formed on the transfer printing sheet and the case where an image is formed, and Figures (c) and (d) show the state after the transfer printing sheets of (a) and (b) have been transferred to fabric. Figures (a) and (b) compare the case where transparent toner is not image-formed on the transfer printing sheet and the case where an image is formed, and Figures (c) and (d) show the state after the transfer printing sheets of (a) and (b) have been transferred to fabric. This is a diagram of an image forming apparatus equipped with a belt unit having a secondary transfer roller. This is a table showing the measurement results of the opacity rate.

[0024] The embodiments of this disclosure will be described in detail below, with reference to the drawings as appropriate. In the following description, directions will be described as those shown in Figure 1. The left side of Figure 1 will be referred to as "front," the right side as "back," the far side of the page in Figure 1 as "left," and the near side as "right." The top and bottom of Figure 1 will be referred to as "top and bottom." In this embodiment, the left-right direction corresponds to the axial direction of the photosensitive drum or the axial direction of the first rotating body. The front-back direction corresponds to a predetermined direction perpendicular to the up-down direction and the axial direction of the photosensitive drum 121. In the following description, the direction in which multiple photosensitive drums are lined up will be referred to as the "first direction."

[0025] The transfer printing sheet creation apparatus 1 shown in Figure 1 is an apparatus for creating the transfer printing sheet PS shown in Figure 8(a). The transfer printing sheet PS is a sheet for transferring a printed layer to an object via a viscoelastic layer PF3. The object is, for example, a fabric CL such as a T-shirt shown in Figure 9(b). The object may also be made of leather, ceramics, wood, resin, metal, etc. Furthermore, the object is not limited to a flat object but may also be a three-dimensional object.

[0026] As shown in Figure 7(c), the transfer printing sheet PS is a sheet in which a sheet S, a toner image T as an example of a printing layer, and a viscoelastic layer PF3 are laminated in this order. Sheet S has a second substrate layer PS1 and a second release layer PS2. The second release layer PS2 is located between the second substrate layer PS1 and the toner image T.

[0027] The second base layer PS1 is a sheet-like base material made of paper or polymer material, and supports the second release layer PS2. The second base layer PS1 is preferably transparent. In this embodiment, the second base layer PS1 is made of polyethylene terephthalate and has a thickness of 12 to 16 μm.

[0028] The second release layer PS2 is the layer on which the toner image T is formed. The second release layer PS2 supports the toner image T and the viscoelastic layer PF3 after the viscoelastic layer PF3 is transferred onto the toner image T formed on the second release layer PS2, and facilitates the peeling of the toner image T and the viscoelastic layer PF3 from the second base layer PS1 when transferring the toner image T and the viscoelastic layer PF3 to a fabric CL or the like. The second release layer PS2 contains a transparent material that is easily peeled from the second base layer PS1, such as a wax-based resin. In this embodiment, the thickness of the second release layer PS2 is 10 to 15 μm.

[0029] Returning to Figure 1, the transfer printing sheet creation apparatus 1 comprises an image forming apparatus 100 and a layer transfer apparatus 200. The layer transfer apparatus 200 is located on top of the image forming apparatus 100. The layer transfer apparatus 200 is detachable from the image forming apparatus 100.

[0030] As shown in Figure 2, the image forming apparatus 100 comprises a first housing 102, a supply unit 103, an image forming unit 104, a first intermediate transport roller MR1, and a cover CV. The first housing 102 houses the supply unit 103, the image forming unit 104, and the first intermediate transport roller MR1. The first housing 102 is an example of the main housing of the image forming apparatus 100.

[0031] As shown in Figure 3, the first housing 102 has an opening 102A. The opening 102A is located on the front side, which is one side in the front-to-back direction, as an example of a first direction. The cover CV is movable between the open position shown in Figure 1 and the closed position shown in Figure 3. When the cover CV is in the open position, the opening 102A is closed. When the cover CV is in the closed position, the opening 102A is exposed.

[0032] The supply unit 103 is located in the lower part of the first housing 102. The supply unit 103 comprises a supply tray 131 and a supply mechanism 134.

[0033] The supply tray 131 is a tray that holds the sheets S. The supply mechanism 134 supplies the sheets S in the supply tray 131 to the image forming unit 104.

[0034] The image forming unit 104 forms a toner image T on the sheet S. The image forming unit 104 comprises an exposure device 105, a drawer 106, a belt unit 107, and a fixing device 108. The drawer 106 is an example of a process unit. The belt unit 107 is an example of a transfer device and a first transfer device.

[0035] The exposure apparatus 105 is located in the upper part of the first housing 102 and includes a light source and a polygon mirror (not shown). The exposure apparatus 105 exposes the surface of the photosensitive drum 121 by rapidly scanning the surface of the photosensitive drum 121 with a light beam shown by a dashed line.

[0036] The drawer 106 is located between the exposure unit 105 and the supply tray 131. The drawer 106 has a drawer frame 120 and four cartridges 160. The cartridges 160 are examples of developer units.

[0037] Here, as shown in Figure 3, the first housing 102 has a drawer rail 102R that guides the drawer 106. The drawer rail 102R extends in the first direction.

[0038] The drawer 106 is positioned on the drawer rail 102R and is slidable along the drawer rail 102R. That is, the drawer 106 is movable in a first direction. With the cover CV in the open position, the drawer 106 can be pulled out of the first housing 102 through the opening 102A. The drawer 106 is pulled out in the pulling direction. In this embodiment, the pulling direction is from front to back. With the drawer 106 pulled out of the first housing 102, the four cartridges 160 are exposed and detachable.

[0039] Returning to Figure 2, the drawer frame 120 comprises four photosensitive drums 121, four chargers 122, and four recovery rollers 123.

[0040] The four photosensitive drums 121 are arranged in a row. In this embodiment, the four photosensitive drums 121 are arranged in a first direction. The photosensitive drums 121 are rotatably supported on the drawer frame 120.

[0041] There are four chargers 122, one for each of the four photosensitive drums 121. The chargers 122 charge the photosensitive drums 121.

[0042] The recovery rollers 123 are arranged in four positions, corresponding to the four photosensitive drums 121. The recovery rollers 123 rotate in contact with the photosensitive drums 121. The recovery rollers 123 are capable of recovering toner from the photosensitive drums 121.

[0043] Multiple cartridges 160 are held in a drawer frame 120 in a first-direction arrangement. Furthermore, each cartridge 160 is detachably held relative to the drawer frame 120. Each cartridge 160 includes a toner container 161, a developing roller 162, a supply roller 163, and an agitator 164. Cartridge 160 is an example of a developing unit and supplies toner to the photosensitive drum 121.

[0044] The toner container 161 accommodates toner. In the present embodiment, the four toner containers 161 respectively accommodate toners of yellow, magenta, cyan and white colors. Here, the toner container 161 that accommodates yellow toner Y is referred to as a yellow container 161Y. The toner container 161 that accommodates magenta toner M is referred to as a magenta container 161M. The toner container 161 that accommodates cyan toner C is referred to as a cyan container 161C. The toner container 161 that accommodates white toner W is referred to as a white container 161W. The white toner W is a toner containing a white pigment. In the present embodiment, the white pigment contains titanium oxide.

[0045] Here, the cartridge 160 including the yellow container 161Y is referred to as a yellow cartridge 160Y. The yellow cartridge 160Y supplies yellow toner Y. The cartridge 160 including the magenta container 161M is referred to as a magenta cartridge 160M. The magenta cartridge 160M supplies magenta toner M. The cartridge 160 including the cyan container 161C is referred to as a cyan cartridge 160C. The cyan cartridge 160C supplies cyan toner C. The cartridge 160 including the white container 161W is referred to as a white cartridge 160W. The white cartridge 160W supplies white toner W.

[0046] The bulk specific gravity of the white toner W is higher than that of the yellow toner Y, the magenta toner M and the cyan toner C. Therefore, in a state where the same volume of toner is filled, the white cartridge 160W is heavier than the other cartridges 160. In the present embodiment, the weight of the white cartridge 160W is about 1.6 times greater than that of the other cartridges 160. The white cartridge 160W is held on the upstream side in the drawing direction of the drawer 106 relative to any of the other cartridges 160.

[0047] In the present embodiment, the yellow cartridge 160Y, the magenta cartridge 160M, the cyan cartridge 160C, and the white cartridge 160W are arranged in this order in the conveyance direction of the sheet S. The white cartridge 160W is located downstream of any of the other cartridges 160 in the conveyance direction of the sheet S. Therefore, as shown in Fig. 7(a), an image is formed on the sheet S in the order of yellow toner Y, magenta toner M, cyan toner C, and white toner W.

[0048] As shown in Fig. 7(a), in the image forming apparatus 100, after a first toner image T1 formed of yellow toner Y, magenta toner M, and cyan toner C is formed on the sheet S conveyed on the belt 173, a second toner image T2 formed of white toner W containing a white pigment is formed on the first toner image T1. That is, among the plurality of cartridges 160, the cartridge 160 that supplies the toner for the toner image T closest to the viscoelastic layer PF3 is the white cartridge 160W.

[0049] Returning to Fig. 2, the developing roller 162 supplies the toner stored in the toner container 161 to the photosensitive drum 121. The supply roller 163 supplies toner to the developing roller 162.

[0050] The agitator 164 is disposed inside the toner container 161. The agitator 164 agitates the toner in the toner container 161 by rotating. The agitator 164 included in the yellow cartridge 160Y is referred to as a yellow agitator 164Y. The yellow agitator 164Y agitates the toner in the yellow container 161Y. The agitator 164 included in the magenta cartridge 160M is referred to as a magenta agitator 164M. The magenta agitator 164M agitates the toner in the magenta container 161M. The agitator 164 included in the cyan cartridge 160C is referred to as a cyan agitator 164C. The cyan agitator 164C agitates the toner in the cyan container 161C. The agitator 164 included in the white cartridge 160W is referred to as a white agitator 164W. The white agitator 164W agitates the toner in the white container 161W.

[0051] As shown in Figure 4(a), the image forming apparatus 100 is equipped with a separation mechanism SM. The separation mechanism SM moves the developing roller 162 between a contact position in which the developing roller 162 is in contact with the photosensitive drum 121 and a separation position in which the developing roller 162 is separated from the photosensitive drum 121.

[0052] The belt unit 107 transfers toner from the photosensitive drum 121 to the sheet S, forming a toner image T on the sheet S. The belt unit 107 is located between the drawer 106 and the supply tray 131. The belt unit 107 comprises a drive roller 171, a driven roller 172, a belt 173, four transfer rollers 174, and a belt cleaner 175.

[0053] Belt 173 is an endless belt. Belt 173 faces the photosensitive drum 121. Belt 173 is stretched between the drive roller 171 and the driven roller 172. Inside belt 173, a transfer roller 174 is positioned to sandwich the belt 173 between itself and the corresponding photosensitive drum 121. Belt cleaner 175 is located beneath belt 173. Belt cleaner 175 is in contact with the surface of belt 173. Belt cleaner 175 collects and stores any remaining toner on belt 173.

[0054] The charger 122 charges the surface of the photosensitive drum 121. Then, the exposure device 105 exposes the surface of the photosensitive drum 121 to form an electrostatic latent image based on the image data on the surface of the photosensitive drum 121. The developing roller 162 supplies toner to the electrostatic latent image formed on the photosensitive drum 121. This forms a toner image T on the photosensitive drum 121. Then, when the sheet S is transported between the photosensitive drum 121 and the transfer roller 174 by the belt 173, the toner image T on the photosensitive drum 121 is transferred to the sheet S.

[0055] The fixing device 108 is a device that heat-fixes a toner image T onto a sheet S. The fixing device 108 is located behind the drawer 106 and the belt unit 107. The fixing device 108 has a first heating roller 181, a first pressurizing member 182, and a fixing transport roller 183. The first heating roller 181 has a first heater H1 inside. The first heater H1 heats the first heating roller 181. The first heating roller 181 heats the sheet S.

[0056] The first intermediate conveyor roller MR1 is a roller that conveys the sheet S, which has passed through the fixing device 108, toward the layer transfer device 200. The first intermediate conveyor roller MR1 is located downstream of the fixing conveyor roller 183 in the conveying direction of the sheet S.

[0057] As shown in Figure 5, the layer transfer apparatus 200 is a device that places a film PF consisting of multiple layers on the surface of a sheet S on which a toner image T is formed, and transfers the viscoelastic layer PF3 of the film PF onto the toner image T.

[0058] The layer transfer apparatus 200 comprises a second housing 202, a second intermediate transport roller MR2, a first sheet sensor SS1, a second sheet sensor SS2, a sheet transport unit 210, a film supply unit 230, and a transfer unit 250. The transfer unit 250 is an example of a second transfer layer.

[0059] The second housing 202 houses the second intermediate transport roller MR2, the first sheet sensor SS1, the second sheet sensor SS2, the sheet transport unit 210, the film supply unit 230, and the transfer unit 250. The second housing 202 is located on top of the first housing 102. The second housing 202 has an outlet 203 for the sheet S (more specifically, the transfer printing sheet PS). The outlet 203 is located on the front of the second housing 202. The outlet 203 faces diagonally downwards and forwards.

[0060] The first housing 102 and the second housing 202 constitute the housing 10 of the transfer printing sheet creation device 1. In this embodiment, the housing of the transfer printing sheet creation device 1 is composed of two housings, but it may also be composed of a single housing in which the first housing 102 and the second housing 202 are integrally formed.

[0061] The second intermediate transport roller MR2 is a roller that transports the sheet S, which is transported from the image forming apparatus 100, toward the transfer section 250. As shown in Figure 1, the first intermediate transport roller MR1 and the second intermediate transport roller MR2 each transport the sheet S, which is transported from the first heating roller 181, toward the second heating roller 260.

[0062] The first sheet sensor SS1 and the second sheet sensor SS2 are sensors that detect the presence or absence of sheet S. The first sheet sensor SS1 and the second sheet sensor SS2 are located along the transport path R.

[0063] As shown in Figure 5, the sheet conveying unit 210 includes an upstream conveying roller 211, a downstream conveying roller 212, a discharge roller 213, and a conveying chute 290. The upstream conveying roller 211, the downstream conveying roller 212, and the discharge roller 213 each consist of two rollers, and the sheet S is conveyed by the rotation of each roller with the sheet S sandwiched between them.

[0064] The upstream conveyor roller 211 is positioned upstream of the transfer section 250 in the conveying direction of the sheet S. The downstream conveyor roller 212 is positioned downstream of the transfer section 250 in the conveying direction of the sheet S.

[0065] The discharge roller 213 is positioned downstream of the downstream conveying roller 212 in the direction of conveying the sheet S. The discharge roller 213 discharges the sheet S from the discharge port 203.

[0066] The conveying chute 290 is located downstream of the second heating roller 260 in the conveying direction of the sheet S. The conveying chute 290 guides the sheet S discharged from the second heating roller 260. The conveying chute 290 holds the downstream conveying roller 212 and the discharge roller 213.

[0067] The film supply unit 230 is the part that supplies film PF so as to overlap it with the sheet S conveyed from the upstream transport roller 211. The film supply unit 230 has a film cartridge FC.

[0068] The film unit FU is detachable from the second housing 202. The film unit FU has a film cartridge FC and a holder H. The film cartridge FC is detachable from the holder H. The film cartridge FC has a film PF, a supply reel 231 and a take-up reel 235. As shown in Figure 7(a), the film PF includes a viscoelastic layer PF3 and is a film for transferring the viscoelastic layer PF3. The film PF has a first base layer PF1, a first release layer PF2 and a viscoelastic layer PF3. The first release layer PF2 is formed on the first base layer PF1. The viscoelastic layer PF3 is formed on the first release layer PF2.

[0069] The first base layer PF1 supports the first release layer PF2 and the viscoelastic layer PF3. In this embodiment, the first base layer PF1 is made of polyethylene terephthalate and has a thickness of 12 to 16 μm.

[0070] The first release layer PF2 is a layer designed to facilitate the peeling of the viscoelastic layer PF3 from the first substrate layer PF1, and is positioned between the first substrate layer PF1 and the viscoelastic layer PF3. The first release layer PF2 contains a transparent material that is easily peeled from the first substrate layer PF1, such as a wax-based resin. In this embodiment, the thickness of the first release layer PF2 is 10 to 30 μm.

[0071] The viscoelastic layer PF3 is a layer transferred to the toner image T and contains a viscoelastic material. The viscoelastic material is a viscoelastic material made of polymer material. The viscoelastic layer PF3 is a material that readily adheres to the toner image T heated by the transfer unit 250 and also readily adheres to the transfer target, such as fabric. The viscoelastic layer PF3 contains, for example, a vinyl chloride resin or an acrylic resin, but any material suitable for adhesion to the transfer target should be selected. The viscoelastic layer PF3 is located on the surface of the film PF. It is desirable that the viscoelastic layer PF3 is thicker than the first release layer PF2. The thickness of the viscoelastic layer PF3 is 16 to 40 μm. Preferably, the thickness of the viscoelastic layer PF3 is 16 to 25 μm.

[0072] In this embodiment, the viscoelastic layer PF3 contains a white pigment. The white pigment contains titanium dioxide. In this embodiment, the opacity of the viscoelastic layer PF3 is greater than the opacity of the toner image T obtained by solid printing with toner containing the white pigment.

[0073] The method for measuring opacity is specified in JIS K5600-4-1. Specifically, a solid print of toner containing white pigment is made on opacity test paper having both a white and a black background. Similarly, a viscoelastic layer PF3 is transferred to another opacity test paper. After this, the reflectance of the printed areas on the white and black backgrounds, as well as the transferred areas, is measured using a spectrophotometer. The reflectance on the black background is then divided by the reflectance on the white background, and the resulting percentage is obtained as the opacity.

[0074] Furthermore, the half-discharge temperature of the viscoelastic layer PF3 is lower than the half-discharge temperature of the toner. The half-discharge temperature can be measured, for example, as follows: Using a flow tester (Shimadzu Corporation, CFT-500EX), a 1.3 g sample is heated at a heating rate of 6°C / min while a 20 kgf load is applied by a plunger and extruded from a nozzle with a diameter of 1.0 mm and a length of 10.0 mm, and a plot of the flow tester's plunger drop amount against temperature is obtained. The temperature at the inflection point in the plunger drop amount-temperature curve where the plunger drop amount changes from a stable region of zero to an increasing region is defined as the discharge start temperature, and the temperature when half of the sample has discharged is defined as the half-discharge temperature.

[0075] Returning to Figure 5, the supply reel 231 has the film PF wound on it. The take-up reel 235 winds up the film PF. The holder H has a plurality of guide shafts HA that guide the film PF.

[0076] The transfer unit 250 transports the sheet S on which the toner image T is formed and the film PF in an overlapping state, and transfers the viscoelastic layer PF3 onto the toner image T. Specifically, the transfer unit 250 places the sheet S on the film PF being transported from the supply reel 231 toward the take-up reel 235, and heats and pressurizes the sheet S and film PF while sandwiching them together. The transfer unit 250 is equipped with a pressure roller 251 and a second heating roller 260.

[0077] The pressure roller 251 is a roller that sandwiches the film PF and the sheet S between itself and the second heating roller 260. The pressure roller 251 is positioned above the film PF and is able to contact the surface of the sheet S opposite to the surface on which the toner image T is formed. The pressure roller 251 conveys the film PF and the sheet S between itself and the second heating roller 260 while being pressed against it.

[0078] The second heating roller 260 is a roller that heats the film PF and the sheet S. The second heating roller 260 includes a second heater H2 and a roller 261.

[0079] The second heater H2 heats the roller 261. The roller 261 is formed in a cylindrical shape and comes into contact with the film PF. The roller 261 comes into contact with the film PF and heats the film PF and the sheet S.

[0080] The second heating roller 260 transfers the viscoelastic layer PF3 onto the toner image T by transporting the sheet S on which the toner image T has been formed by the first heating roller 181 and the film PF having the viscoelastic layer PF3 in an overlapping state.

[0081] The second heating roller 260 is movable between a contact position with the pressure roller 251 and a separated position away from the pressure roller 251 by a moving mechanism (not shown). The pressure roller 251 and the second heating roller 260 can convey the film PF and the sheet S by being driven while in contact. Specifically, the pressure roller 251 is rotationally driven when the second heating roller 260 is in the contact position, causing the second heating roller 260 to rotate in its favor. As a result, the pressure roller 251 and the second heating roller 260 convey the film PF and the sheet S sandwiched between them.

[0082] In the layer transfer apparatus 200 configured in this way, the sheet S transported from the image forming apparatus 100 is transported toward the transfer section 250. The sheet S is placed on top of the film PF supplied from the supply reel 231 upstream of the sheet transport direction in the transfer section 250, and the sheet S is transported toward the transfer section 250 with the toner image T on the sheet S and the film PF in contact.

[0083] In the transfer section 250, as the sheet S and film PF pass through the nip between the pressure roller 251 and the second heating roller 260, they are heated and pressurized by the second heating roller 260 and the pressure roller 251, and the viscoelastic layer PF3 is transferred onto the toner image T formed on the sheet S. In the following description, the transfer of the viscoelastic layer PF3 to the sheet S will also be simply referred to as "layer transfer." After the layer transfer is performed, the sheet S is discharged to the outside of the second housing 202.

[0084] As shown in Figure 4(b), the transfer printing sheet creation apparatus 1 further comprises a control unit CU, a motor MT, a first clutch K1, a second clutch K2, a third clutch K3, and a fourth clutch K4.

[0085] The control unit (CU) includes a CPU, ROM, RAM, input / output unit, etc., and controls the operation of the image forming apparatus 100 and the layer transfer apparatus 200 by executing a pre-stored program.

[0086] Motor MT drives the yellow agitator 164Y, magenta agitator 164M, cyan agitator 164C, and white agitator 164W.

[0087] The first clutch K1 is located between the motor MT and the yellow agitator 164Y. The first clutch K1 turns on or off the driving force transmitted from the motor MT to the yellow agitator 164Y according to a command from the control unit CU. The second clutch K2 is located between the motor MT and the magenta agitator 164M. The second clutch K2 turns on or off the driving force transmitted from the motor MT to the magenta agitator 164M according to a command from the control unit CU. The third clutch K3 is located between the motor MT and the cyan agitator 164C. The third clutch K3 turns on or off the driving force transmitted from the motor MT to the cyan agitator 164C according to a command from the control unit CU. The fourth clutch K4 is located between the motor MT and the white agitator 164W. The fourth clutch K4 turns on or off the driving force transmitted from the motor MT to the white agitator 164W according to a command from the control unit CU.

[0088] Next, the control performed by the control unit CU when forming an image and when collecting toner from the photosensitive drum 121 will be explained with reference to Figure 6.

[0089] As shown in Figure 6(a), when forming an image, the control unit CU applies a charging bias Vg to the charger 122. When forming an image, the control unit CU applies a developing bias Vb to the developing roller 162 that has the same polarity as the charging bias Vg but is smaller than the charging bias Vg. At this time, as shown in Figure 4(a), the control unit CU controls the separation mechanism SM to position the developing roller 162 in the pressure contact position. When forming an image, the control unit CU applies a transfer bias Vt that has the opposite polarity to the charging bias Vg to the transfer roller 174. When forming an image, the control unit CU applies a recovery bias Vc that has the opposite polarity to the charging bias Vg to the recovery roller 123.

[0090] In this embodiment, the toner is positively charged. Therefore, when forming an image, the control unit CU sets the charge bias Vg and the develop bias Vb to positive polarity. The control unit CU also sets the transfer bias Vt and the recovery bias Vc to negative polarity. As a result, when toner is supplied onto the photosensitive drum 121, a toner image is formed on the exposed surface of the photosensitive drum 121. The toner image is then transferred to the sheet S by the transfer roller 174. Any toner remaining on the photosensitive drum 121 that is not transferred to the sheet S is recovered by the recovery roller 123. Any toner that is not recovered by the recovery roller 123 is given a positive charge by the charger 122, recovered by the develop roller 162, and returned to the toner container 161. This allows some of the toner to be reused for image formation.

[0091] As shown in Figure 6(b), when the toner collected by the recovery roller 123 is moved to the belt cleaner 175, the control unit CU performs ejection control. Ejection control is the control that ejects the toner collected by the recovery roller 123 from the recovery roller 123 to the photosensitive drum 121 and moves it to the belt 173.

[0092] When performing ejection control, the control unit CU controls the separation mechanism SM to position the developing roller 162 in the separated position. When performing ejection control, the control unit CU applies a recovery bias Vc of the same polarity as the charging bias Vg to the recovery roller 123.

[0093] In this embodiment, when ejection control is performed, the control unit CU sets the recovery bias Vc to positive polarity. As a result, the toner recovered by the recovery roller 123 is ejected onto the photosensitive drum 121.

[0094] After the toner collected by the recovery roller 123 is discharged onto the photosensitive drum 121, the control unit CU moves the toner on the photosensitive drum 121 to the belt 173. As shown in Figure 6(c), when the control unit CU moves the toner on the photosensitive drum 121 to the belt 173, it applies a transfer bias Vt with the opposite polarity to the charge bias Vg to the transfer roller 174.

[0095] In this embodiment, the control unit CU sets the transfer bias Vt to negative polarity. As a result, the toner discharged from the recovery roller 123 to the photosensitive drum 121 moves from the photosensitive drum 121 to the belt 173.

[0096] As shown in Figure 2, the toner that has moved onto the belt 173 is collected and stored in the belt cleaner 175.

[0097] Next, the drive timing for driving the agitator 164 controlled by the control unit CU will be described. The control unit CU controls the first clutch K1 to turn on or off the drive force transmitted from the motor MT to the yellow agitator 164Y. The control unit CU controls the second clutch K2 to turn on or off the drive force transmitted from the motor MT to the magenta agitator 164M. The control unit CU controls the third clutch K3 to turn on or off the drive force transmitted from the motor MT to the cyan agitator 164C. The control unit CU controls the fourth clutch K4 to turn on or off the drive force transmitted from the motor MT to the white agitator 164W.

[0098] The control unit CU starts driving the white agitator 164W, the yellow agitator 164Y, the magenta agitator 164M, and the cyan agitator 164C at different timings. That is, it controls the system so that the white agitator 164W and the other agitators 164 are not driven simultaneously. In this embodiment, the control unit CU starts driving the white agitator 164W after a predetermined time has elapsed since starting to drive the yellow agitator 164Y, the magenta agitator 164M, and the cyan agitator 164C.

[0099] When an image formation command is received, the control unit (CU) determines whether or not to form a toner image T2 containing white pigment. Therefore, with reference to Figure 10(a), the control for determining whether or not to form a toner image T2 will be described.

[0100] As shown in Figure 10(a), the control unit CU determines whether or not to form a second toner image T2, which is formed with toner containing white pigment, for each predetermined range. When an image formation command is received, the control unit CU calculates the area occupancy rate of the first toner image T1, which is formed from yellow, magenta, and cyan toners, within a predetermined range. The control unit CU determines whether or not to form the second toner image T2 according to the area occupancy rate of the first toner image T1 within a predetermined range.

[0101] The predetermined range corresponds to the range of the dither matrix. The dither matrix corresponds to the gradation of the image data, and the predetermined range is a pattern of binary pixels. The area occupancy rate of the yellow, magenta, and cyan toner images within the predetermined range is a maximum of 100%. The area occupancy rate of the first toner image T1 formed from yellow, magenta, and cyan toners within the predetermined range becomes a maximum of 300% when the colors are superimposed. The control unit CU forms the second toner image T2 when the area occupancy rate of the first toner image T1 within the predetermined range is less than the threshold. Here, the threshold may be a value greater than 100%, and as an example, it can be set to 150%.

[0102] As shown in Figure 10(a), the control unit CU does not form the second toner image T2 in a predetermined area if the area occupancy rate of the first toner image T1 in that area is greater than or equal to a threshold. This is because, if the area occupancy rate of the first toner image T1 in the predetermined area is greater than or equal to a threshold, the color development of the first toner image T1 will not deteriorate whether or not the second toner image T2 is formed as a base layer.

[0103] As shown in Figure 10(b), the control unit CU forms a second toner image T2 in a predetermined area if the area occupancy rate of the first toner image T1 in that area is less than a threshold. This is because if the area occupancy rate of the first toner image T1 in the predetermined area is less than a threshold, and the second toner image T2 is not formed as a base for the first toner image T1, the color of the object will show through and the color development of the first toner image T1 will be poor.

[0104] Furthermore, even in areas where the first toner image T1 is not formed, the second toner image T2 may be formed in any area specified by the user. If the second toner image T2 is formed in an area where the first toner image T1 is not formed, a white image will be formed.

[0105] Next, referring to Figures 8 to 10, we will explain the pressing process in which the toner image T and the viscoelastic layer PF3 are pressed onto a fabric CL, which is an example of an object.

[0106] In the crimping process, a dedicated press machine (not shown in the diagram) is used. This dedicated press machine is a device that places a transfer printing sheet PS on top of the fabric CL and then heats and presses it into place.

[0107] As shown in Figure 8(a), the transfer printing sheet PS is placed on top of the fabric CL and heated and pressed using a dedicated press machine. As a result, the toner image T and the viscoelastic layer PF3 are pressed onto the fabric CL.

[0108] Once the toner image T and the viscoelastic layer PF3 have been pressed onto the fabric CL, the user peels off the second base layer PS1 of the transfer printing sheet PS. After peeling off the second base layer PS1 of the transfer printing sheet PS, only the toner image T and the viscoelastic layer PF3 remain on the fabric CL, as shown in Figure 8(b).

[0109] As shown in Figure 10(c), if the area occupancy rate of the first toner image T1 in a predetermined range is greater than or equal to a threshold, the first toner image T1 and the viscoelastic layer PF3 are transferred to the fabric CL. More specifically, the viscoelastic layer PF3 is placed on top of the fabric CL, and the first toner image T1 is placed on top of the viscoelastic layer PF3.

[0110] As shown in Figure 10(d), when the area occupancy rate of the first toner image T1 in a predetermined range is less than a threshold, the first toner image T1, the second toner image T2, and the viscoelastic layer PF3 are transferred to the fabric CL. Specifically, the viscoelastic layer PF3 is placed on top of the fabric CL, the second toner image T2 is placed on top of the viscoelastic layer PF3, and the first toner image T1 is placed on top of the second toner image T2. In this case, the viscoelastic layer PF3, which contains white pigment, overlaps the second toner image T2, which contains white pigment.

[0111] An example of a transfer printing sheet PS is shown in Figure 9(a). A mirror image of the toner image T, which is covered with a viscoelastic layer PF3, is formed on the surface of the transfer printing sheet PS. The mirror image of the toner image T is a mirror image of the image to be transferred to the fabric CL. In this embodiment, an example of transferring the image of the letters "ABC" to the fabric CL is shown. In this case, a mirror image of "ABC" that is reversed left to right is formed on the sheet S.

[0112] As shown in Figure 9(b), the user presses the transfer printing sheet PS onto the fabric CL and heats and presses it with a dedicated press machine. As a result, as shown in Figure 9(c), the first toner image T1 and the second toner image T2 are bonded to the fabric CL via the viscoelastic layer PF3.

[0113] As described above, the following effects can be obtained according to this embodiment. When a toner image T is transferred to an object such as a T-shirt or other fabric CL, if the object is dark in color, the color of the object may show through. However, in this embodiment, the viscoelastic layer PF3 that transfers the toner image T to the object contains a white pigment. Therefore, when a toner image T is transferred to an object, the color of the object does not show through, which can be suppressed.

[0114] Furthermore, because the white pigment contained in the viscoelastic layer PF3 of the transfer printing sheet PS contains titanium dioxide, it has a high opacity and can suppress the transparency of the color of the object being printed on.

[0115] Furthermore, as shown in Figure 10(d), by layering a viscoelastic layer PF3 containing a white pigment onto the second toner image T2 containing a white pigment, the transparency of the object's color can be further suppressed.

[0116] Furthermore, because the white pigment in the toner contains titanium dioxide, it has a high opacity, which helps to suppress the transparency of the object's color.

[0117] Furthermore, cartridges 160 other than the white cartridge 160W, which supplies toner containing white pigment, supply yellow, magenta, and cyan toners. This allows for the formation of full-color images, as well as the formation of black images by layering yellow, magenta, and cyan.

[0118] Furthermore, the white cartridge 160W, which contains a white pigment containing metal atoms, is heavier than the other cartridges 160. However, as shown in Figure 3, the white cartridge 160W is held upstream of the drawer 106 in the pulling-out direction, more so than any of the other cartridges 160. Therefore, when the drawer 106 is pulled out of the first housing 102, a large change in the overall weight balance of the image forming apparatus 100 can be suppressed. If the white cartridge 160W were held downstream of the drawer 106 in the pulling-out direction, the overall weight balance of the image forming apparatus 100 may shift to the front when the drawer 106 is pulled out. If the overall weight balance of the image forming apparatus 100 shifts to the front, the rigidity of the first housing 102 and cover CV would need to be increased, which could lead to increased costs.

[0119] Furthermore, starting to drive the white agitator 164W, which agitates the high-density white toner W, requires a larger torque compared to starting to drive the agitators 164 that agitate the other colored toners. Therefore, the control unit CU can suppress the load on the motor MT by differentiating the timing of starting the white agitator 164W and the other agitators 164. Suppressing the load on the motor MT can prevent the motor MT from becoming larger.

[0120] Furthermore, white toner containing white pigment has poorer transferability compared to toner without white pigment, making it more likely for toner to remain on the photosensitive drum 121. Therefore, by providing a recovery roller 123 that rotates in contact with the photosensitive drum 121, the toner remaining on the photosensitive drum 121 can be efficiently recovered.

[0121] Furthermore, when the recovery roller 123 discharges the toner it has collected onto the photosensitive drum 121, the control unit CU applies a recovery bias Vc to the recovery roller 123 that has the same polarity as the charging bias Vg applied to the charger 122. As a result, toner is efficiently discharged from the recovery roller 123, and the accumulation of toner on the recovery roller 123 is suppressed.

[0122] Furthermore, when the recovery roller 123 discharges the toner it has collected from the recovery roller 123 to the photosensitive drum 121, the control unit CU positions the developing roller 162 at a distanced position. This prevents any remaining toner collected by the recovery roller 123 from moving to the developing roller 162.

[0123] Furthermore, when the control unit CU performs ejection control, it moves the toner ejected from the recovery roller 123 to the photosensitive drum 121 from the photosensitive drum 121 to the belt 173. This allows the toner collected by the recovery roller 123 to be discharged.

[0124] Although embodiments have been described above, the present invention is not limited to the embodiments described above and can be implemented by modifying them as shown below. In the following description, components similar to those described above are denoted by the same reference numerals and their descriptions are omitted.

[0125] In the above embodiment, the cartridge 160 that supplies the toner image T closest to the viscoelastic layer PF3 contained white toner W containing a white pigment, but it may also contain transparent toner R. Transparent toner R refers to toner that does not contain white pigment or other colorants, and includes translucent toner.

[0126] In this configuration, transparent toner R is used instead of white toner W to form a third toner image T3 using the transparent toner R. As shown in Figure 11(a), the control unit CU does not form the third toner image T3 in a predetermined range if the area occupancy rate of the first toner image T1 in that range is greater than or equal to a threshold. As shown in Figure 11(b), the control unit CU forms the third toner image T3 in a predetermined range if the area occupancy rate of the first toner image T1 in that range is less than a threshold. Furthermore, even in areas where the first toner image T1 is not formed, the third toner image T3 may be formed in any area specified by the user.

[0127] Similar to the embodiment described above, the transfer printing sheet PS is placed on the fabric CL and heated and pressed with a dedicated press. As shown in Figure 11(c), the viscoelastic layer PF3 is transferred when the area occupancy rate in a predetermined range of the first toner image T1, which is composed of yellow, magenta, and cyan, is greater than or equal to a threshold. However, when the area occupancy rate in a predetermined range of the first toner image T1, which is composed of yellow, magenta, and cyan, is less than the threshold, the viscoelastic layer PF3 is not sufficiently transferred. However, by forming a third toner image T3 with transparent toner R, the viscoelastic layer PF3 containing white pigment can be transferred to any part, as shown in Figure 11(d). In this form as well, since the viscoelastic layer PF3 contains white pigment, the transparency of the color of the object can be suppressed.

[0128] In the above-described embodiment, the viscoelastic layer PF3 contained a white pigment, but the viscoelastic layer PF3 does not necessarily contain a white pigment. In this case, by transferring the second toner image T2 containing a white pigment to the object, the transparency of the object's color can be suppressed.

[0129] In the above-described embodiment, a belt unit 107 without a secondary transfer roller was exemplified as an example of a transfer device and a first transfer device, but a belt unit having a secondary transfer roller can be used. For example, the belt unit 207 shown in Figure 12 has an intermediate transfer belt 273, a primary transfer roller 274, and a secondary transfer roller 276. The primary transfer roller 274 transfers the toner image T on the photosensitive drum 121 to the intermediate transfer belt 273. The secondary transfer roller 276 transfers the toner image T on the intermediate transfer belt 273 to the sheet S. The intermediate transfer belt 273 rotates counterclockwise as shown. An image is formed on the intermediate transfer belt 273 in the order of white toner W, cyan toner C, magenta toner M, and yellow toner Y. The image formed on the intermediate transfer belt 273 is transferred to the sheet S by the secondary transfer roller 276. On the sheet S, an image is formed in the order of yellow toner Y, magenta toner M, cyan toner C, and white toner W, starting from the side closest to the second release layer PS2. An image forming apparatus equipped with the belt unit 207 shown in Figure 12 can also obtain the same effects as the embodiment described above.

[0130] In the above-described embodiment, the yellow cartridge 160Y, magenta cartridge 160M, and cyan cartridge 160C were arranged in this order in the transport direction of the sheet S, but the order of these three color cartridges 160 can be changed as appropriate.

[0131] In the above embodiment, a toner with positive polarity was used, but a toner with negative polarity may also be used.

[0132] In the above-described embodiment, the white pigment contained titanium dioxide, but the white pigment may also contain zinc oxide, organic white pigments, or other pigments besides titanium dioxide.

[0133] In the embodiment described above, the four photosensitive drums 121 were arranged in the front-to-back direction as an example of the first direction, but the first direction is not limited to the front-to-back direction. For example, the first direction may be a direction inclined with respect to the front-to-back direction.

[0134] In the above-described embodiment, the drawer 106 was drawn out from front to back, but the drawer 106 may also be drawn out in a direction inclined with respect to the first direction or the front-to-back direction.

[0135] In the above-described embodiment, the control unit CU started driving the white agitator and the other color agitators at different timings. However, the driving timing of the developing roller and supply roller corresponding to the white toner may be started at a different timing than that of the developing roller and supply roller of the other colors.

[0136] In the above-described embodiment, the control unit CU controls the first clutch K1, the second clutch K2, the third clutch K3, and the fourth clutch K4, but the separation mechanism SM and the agitator may be linked. For example, when the developing roller 162 is in the contact position due to the separation mechanism SM, a driving force may be transmitted from the motor MT to the agitator 164, and when the developing roller 162 is in the separated position, a driving force may not be transmitted from the motor MT to the agitator 164.

[0137] In the above-described embodiment, the control unit CU determined whether or not to form a white toner image for each predetermined range corresponding to the dither matrix, but the predetermined range can be determined arbitrarily.

[0138] In the above embodiment, a cartridge having a developing roller and a supply roller was exemplified, but the cartridge can be any cartridge containing toner, and does not necessarily have to have a developing roller and a supply roller.

[0139] The elements described in the above embodiments and modifications may be implemented in any combination.

[0140] The following describes the experimental results that confirmed the difference in opacity depending on the combination of white toner and a viscoelastic layer containing white pigment. Figure 13 shows the results of measuring the opacity for each combination of formed image and viscoelastic layer.

[0141] The experimental conditions were as follows: The transparent toner was a toner that did not contain white pigment or other colorants. Three types of white toner were used: white toner W1, white toner W2, and white toner W3. White toner W2 has a higher white pigment content than white toner W1. White toner W3 has a higher white pigment content than white toner W2. The white pigment is titanium dioxide. The viscoelastic layer contains titanium dioxide as the white pigment. The image was formed by solid printing on opacity test paper. The image area occupancy rate was 100%. Images were formed under the same conditions for white toner W1, white toner W2, and white toner W3. The viscoelastic layer was formed by transferring the image onto the white toner. The thickness of the viscoelastic layer was 16 μm. The opacity was measured according to JIS K5600-4-1.

[0142] Under the conditions described above, the opacity was measured and the following results were obtained: (1) The opacity of the image with the transparent toner and viscoelastic layer superimposed was 75%. That is, the opacity of the viscoelastic layer PF3 alone was 75%. (2) The opacity of the image formed with only the white toner W1 was 53%. (3) The opacity of the image with the white toner W1 and viscoelastic layer superimposed was 82%. (4) The opacity of the image formed with only the white toner W2 was 61%. (5) The opacity of the image with the white toner W2 and viscoelastic layer superimposed was 83%. (6) The opacity of the image formed with only the white toner W3 was 72%. (7) The opacity of the image with the white toner W3 and viscoelastic layer superimposed was 86%.

[0143] It was confirmed that an opacity of 70% or more can be achieved using only a viscoelastic layer.

[0144] 1 Transfer printing sheet creation apparatus 100 Image forming apparatus 102 First housing 106 Drawer 121 Photosensitive drum 122 Charger 123 Recovery roller 160 Cartridge 173 Belt 200 Layer transfer apparatus 202 Second housing PF Film PF3 Viscoelastic layer PS Transfer printing sheet S Sheet

Claims

1. A transfer printing sheet making apparatus for creating a transfer printing sheet in which a sheet, a printing layer, and a viscoelastic layer are laminated in this order, and for transferring the printing layer to an object via the viscoelastic layer, comprising: a photosensitive drum; an exposure device for exposing the photosensitive drum; a developer for supplying toner to the photosensitive drum; a first transfer device for transferring the toner supplied on the photosensitive drum to a sheet and forming the printing layer on the sheet; a fixing device for fixing the printing layer to the sheet; a film cartridge having a film having the viscoelastic layer, a supply reel around which the film is wound, and a take-up reel for winding the film; and a second transfer device for transporting the sheet with the printing layer formed on it and the film in a stacked state and transferring the viscoelastic layer onto the printing layer, wherein the viscoelastic layer contains a white pigment.

2. The transfer printing sheet preparation apparatus according to claim 1, characterized in that the white pigment contained in the viscoelastic layer contains titanium dioxide.

3. The transfer printing sheet creation apparatus according to claim 1, wherein a plurality of developing units are provided, and among the plurality of developing units, the developing unit that supplies the toner for the printing layer closest to the viscoelastic layer supplies toner containing a white pigment.

4. The transfer printing sheet preparation apparatus according to claim 3, characterized in that the white pigment contained in the toner contains titanium dioxide.

5. The transfer printing sheet preparation apparatus according to claim 3, characterized in that the opacity of the viscoelastic layer is greater than the opacity of the printing layer in which toner containing a white pigment is solidly printed.

6. The transfer printing sheet making apparatus according to claim 3, characterized in that, among the plurality of developers, the developers other than the developer that supplies toner containing white pigment include a developer that supplies yellow toner, a developer that supplies magenta toner, and a developer that supplies cyan toner.

7. The transfer printing sheet making apparatus according to claim 6, wherein the first transfer apparatus has an endless belt facing the photosensitive drum for transporting a sheet, and the transfer printing sheet making apparatus is configured to form a first toner image on a sheet transported on the belt using yellow, magenta, and cyan toners, and then form a second toner image on the first toner image using a toner containing a white pigment.

8. The transfer printing sheet making apparatus according to claim 6, further comprising a control unit, wherein the control unit determines whether or not to form a toner image containing a white pigment for each predetermined range, and when the area occupancy rate of the toner image formed from yellow, magenta, and cyan toners in the predetermined range is less than a threshold, a second toner image formed from toner containing a white pigment is formed in the predetermined range, and when the area occupancy rate is equal to or greater than the threshold, the second toner image is not formed in the predetermined range.

9. The transfer printing sheet preparation apparatus according to claim 8, characterized in that the predetermined range is a range corresponding to the dither matrix.

10. The transfer printing sheet making apparatus according to claim 1, wherein a plurality of developing units are provided, and among the plurality of developing units, the developing unit that supplies the toner for the printing layer closest to the viscoelastic layer supplies transparent toner.

Images