JP2020083651A - Thermal transfer print device - Google Patents

Abstract

To prevent print material from curling with a simple design.SOLUTION: The thermal transfer print device includes: an image receiving sheet roll wound with an image receiving sheet with a receiving layer on its surface and supplies the image receiving sheet; a thermal head and a platen roll that are provided on a downstream side of the image receiving sheet roll in the image receiving sheet feeding direction and sandwich a thermal transfer sheet with a color material layer and the image receiving sheet; and a capstan roller and a pinch roller that sandwich and feed the image receiving sheet. The thermal head heats the thermal transfer sheet and transfers the color material from the thermal transfer sheet to the image receiving sheet. The capstan roller and pinch roller impart to the image receiving sheet reverse warpage to the warpage caused by winding of the image receiving sheet.SELECTED DRAWING: Figure 1

Description

The present invention relates to a thermal transfer printing device.

As a method for forming an image, a thermal transfer method is known in which a thermal transfer sheet having a dye layer provided on a base material and an image receiving sheet having a receiving layer provided on the base material are superposed on each other to form an image. After image formation, the image receiving sheet is cut into a desired size to produce a printed matter. Since the image-receiving sheet before image formation is installed inside the printer in a rolled-up state, there is a problem that curling occurs in the printed matter after cutting and curl occurs.

A printer provided with a decurling mechanism for reducing curling of an image receiving sheet has been proposed. For example, the decurling mechanism applies a decurling force to the image receiving sheet by using a plurality of rollers to give a warp opposite to the curl. However, when a conventional decal mechanism having a plurality of rollers is additionally provided in the printer separately from the printing mechanism, the structure becomes complicated, which hinders reduction in size and weight of the printer.

Also, in a printer that transfers a transfer layer from a transfer sheet to a card substrate, the card substrate warps due to heat contraction due to transfer layer transfer and subsequent thermal contraction, and the flatness required for a finished card after the transfer process. It may be difficult to satisfy the sex.

JP, 2016-196339, A

The present invention has been made in view of the above-mentioned conventional circumstances, and an object of the present invention is to provide a thermal transfer printing apparatus capable of preventing the printed matter from curling (warping) with a simple configuration.

The thermal transfer printing apparatus according to the present invention, the image receiving sheet having a receiving layer on the surface is wound, the image receiving sheet roll that supplies the image receiving sheet, and provided on the downstream side in the image receiving sheet transport direction than the image receiving sheet roll, A thermal head and a platen roll that sandwich the thermal transfer sheet having a material layer and the image receiving sheet, and a capstan roller and a pinch roller that sandwich and convey the image receiving sheet, and the thermal head heats the thermal transfer sheet. A color material is transferred from the thermal transfer sheet to the image receiving sheet, and the capstan roller and the pinch roller give the image receiving sheet a warp opposite to the warp caused by the winding of the image receiving sheet. ..

In the thermal transfer printing apparatus according to an aspect of the present invention, a first direction orthogonal to a conveyance direction of the image receiving sheet around the thermal head, the platen roll, a capstan roller, and a pinch roller, a rotation center of the capstan roller, and It is not parallel to the second direction connecting the center of rotation of the pinch roller.

In the thermal transfer printing apparatus according to one aspect of the present invention, the pinch angle formed by the first direction and the second direction is 10 degrees or more and 30 degrees or less.

In the thermal transfer printing apparatus according to one aspect of the present invention, a pinch roller moving mechanism that moves the pinch roller along the outer peripheral surface of the capstan roller and adjusts the pinch angle formed by the first direction and the second direction is provided. Further prepare.

In the thermal transfer printing apparatus according to the aspect of the present invention, the pinch roller moving mechanism moves the pinch roller such that the smaller the diameter of the image receiving sheet roll, the larger the pinch angle.

In the thermal transfer printing apparatus according to one aspect of the present invention, the portion where the image receiving sheet starts to contact the pinch roller when viewed from the thermal head side is more than the portion where the capstan roller and the pinch roller sandwich the image receiving sheet. It is located near the thermal head.

The thermal transfer printing apparatus according to the present invention sandwiches a transfer sheet having a transfer layer and a sheet-shaped transfer target, heats the transfer sheet, and transfers the transfer layer from the transfer sheet to the transfer target. And a pressure roller, and a first transport roller and a second transport roller that sandwich and transport the transfer target on which the transfer layer has been transferred, and the first transport roller and the second transport roller are The object to be transferred is provided with a warp opposite to the warp caused by thermal contraction.

In the thermal transfer printing apparatus according to one aspect of the present invention, a first direction orthogonal to a transport direction of the transfer target around the thermal block, the pressure roll, the first transport roller and the second transport roller, and the first transport The second direction connecting the rotation center of the roller and the rotation center of the second transport roller is not parallel.

According to the present invention, it is possible to prevent the printed matter from curling (warping) with a simple configuration.

FIG. 1 is a schematic diagram of a thermal transfer printing apparatus according to an embodiment of the present invention. FIG. 2 is a schematic view of a decal portion according to the same embodiment. 3A and 3B are diagrams showing an example of the decurling process according to the same embodiment. FIG. 4 is a diagram showing a decal portion according to a comparative example. 5A to 5D are graphs showing the experimental results of the curl amount of the printed matter. 6A and 6B are schematic diagrams of a decal portion according to another embodiment. 7A and 7B are schematic views of a thermal transfer printing apparatus according to another embodiment, and FIG. 7C is a cross-sectional view of a transferred body after transfer processing. It is a sectional view of an intermediate transfer sheet. FIG. 9 is a cross-sectional view of a transfer target according to a comparative example.

FIG. 1 is a schematic configuration diagram of a thermal transfer printing apparatus according to an embodiment of the present invention, and FIG. 2 is a partially enlarged view of the thermal transfer printing apparatus.

The thermal transfer printing device TP1 is a thermal transfer in which a yellow dye (Y) layer, a magenta dye (M) layer, a cyan dye (C) layer, and a transferable protective layer (hereinafter referred to as a protective layer) are repeatedly provided in a frame order. The sheet 5 is provided with a thermal head 1 for sublimating and transferring Y, M, and C onto an image receiving sheet 7 to print an image and transferring a protective layer onto the image.

The thermal transfer sheet 5 is unwound from the supply unit 3, passes through the thermal head 1, and is wound up by the recovery unit 4. The thermal transfer sheet 5 is conveyed from the supply unit 3 to the recovery unit 4 along the plurality of guide rollers 8. As the thermal transfer sheet 5, known materials used in this type of thermal transfer printing apparatus can be used. For example, a material in which a sublimable dye is dissolved or dispersed in a binder resin can be used for the dye layer. For the protective layer, it is preferable to use a transparent material having adhesiveness, light resistance and the like. The color material layer provided on the thermal transfer sheet 5 is not limited to a layer containing a sublimable dye, and may be a layer containing a heat-meltable ink.

A platen roll 2 is provided on the side opposite to the thermal head 1 with the thermal transfer sheet 5 and the image receiving sheet 7 interposed therebetween. The printing unit 40 including the thermal head 1 and the platen roll 2 sandwiches the image receiving sheet 7 and the thermal transfer sheet 5 and heats the dye layer of the thermal transfer sheet 5 to thermally transfer the dye onto the image receiving sheet 7 to form an image.

The printing unit 40 also heats the protective layer of the thermal transfer sheet 5 to transfer the protective layer onto the image printed on the image receiving sheet 7. By increasing the transfer energy (printing energy by the printing unit 40) during transfer of the protective layer, the surface of the protective layer becomes matte with low gloss, and by decreasing the transfer energy, the surface of protective layer is glossy with high gloss. become.

The image receiving sheet 7 is unrolled from the image receiving sheet roll 6 obtained by winding the image receiving sheet 7 in a roll shape. As the image-receiving sheet 7, a known one used in this type of thermal transfer printing apparatus can be used. For example, a resin coat layer, paper, an adhesive layer, a void-containing film, and a receiving layer are laminated in this order. Can be used. As the void-containing film, various films can be used as long as voids are formed in the film. For example, it is possible to use a film in which a void is formed in the film by adding a void developing agent to PET (polyethylene terephthalate) and peeling the PET and the void developing agent from each other during the film formation and stretching process. As the base material, in addition to PET, polyolefin such as PP (polypropylene) and PE (polyethylene) can be used.

The printing unit 40 is located downstream of the image receiving sheet roll 6 in the image receiving sheet transport direction. Between the printing unit 40 and the image-receiving sheet roll 6, a capstan roller 9 which is rotatable for carrying the image-receiving sheet 7 and a pinch roller 10 for pressing the image-receiving sheet 7 onto the capstan roller 9 are provided. Is provided. The pinch roller 10 is a roller that comes into contact with the receiving layer on the front surface side of the image receiving sheet 7. The capstan roller 9 is a roller that comes into contact with the back surface side of the image receiving sheet 7, and a large number of spikes that are fine protrusions are provided on the surface thereof. The spike receives the pressure from the pinch roller 10 and digs into the back surface of the image receiving sheet 7, thereby preventing the image receiving sheet 7 from shifting.

The image receiving sheet 7 is conveyed to a predetermined position by the rotation of the capstan roller 9 and the pinch roller 10 that sandwich the image receiving sheet 7.

The image receiving sheet 7 on which the image formation and the transfer of the protective layer have been performed in the image printing section 40 is cut by a cutter (not shown) on the downstream side to produce a printed matter (printed sheet).

As described above, since the image receiving sheet 7 is loaded in the thermal transfer printing apparatus TP1 in a rolled state, the image receiving sheet 7 has a curl. In the present embodiment, the capstan roller 9 and the pinch roller 10 give the image receiving sheet 7 a warp (reverse warp) opposite to the warp generated by the winding of the image receiving sheet roll 6 to flatten the image receiving sheet 7. It functions as a decal portion D that is turned into a decal. In this embodiment, the image receiving sheet 7 is wound in a roll shape so that the front surface is the outer peripheral side and the back surface is the inner peripheral side.

As shown in FIG. 2, the conveying direction of the image receiving sheet 7 around (in the vicinity of) the printing section 40 and the decal section D is d0, and the direction orthogonal to the conveying direction d0 (the direction perpendicular to the image receiving sheet surface) is d1. When the direction connecting the rotation center C1 (rotation shaft) of the capstan roller 9 and the rotation center C2 (rotation shaft) of the pinch roller 10 is d2, the direction d1 (first direction) and the direction d2 (second direction) are defined as Are non-parallel to each other, the direction d1 and the direction d2 intersect at a constant pinch angle θ, and the rotation center C2 of the pinch roller 10 is located closer to the printing section 40 than the rotation center C1 of the capstan roller 9. When the pinch angle θ is other than 0 degree, the direction in which the image receiving sheet 7 is conveyed between the printing section 40 and the decal section D is slightly different from the above-described image receiving sheet conveyance direction d0. When the pinch angle θ is 0 degree (see FIG. 4), the image receiving sheet conveyance direction d0 coincides with the direction in which the image receiving sheet 7 is conveyed between the printing section 40 and the decurling section D.

In other words, in the printing unit 40, the portion where the thermal head 1 and the platen roll 2 sandwich the image receiving sheet 7 (and the thermal transfer sheet 5) is P1, and in the decal portion D, the capstan roller 9 and the pinch roller 10 are the image receiving sheet 7. Assuming that P2 is a portion where the image is sandwiched, and P3 is a portion where the image receiving sheet 7 starts to contact the surface of the pinch roller 10 when viewed from the printing portion 40 side, the contact start portion P3 is closer to the printing portion 40 than the sandwiching portion P2. Located near. The image receiving sheet conveyance direction d0 described above is substantially the same as the direction connecting the pinch point P1 and the pinch point P2.

By arranging the capstan roller 9 and the pinch roller 10 so as to have such a positional relationship, it is possible to add a reverse warp to the image receiving sheet 7 and generate a decal effect. As shown in FIGS. 3A and 3B, the larger the pinch angle θ, the more strongly the image receiving sheet 7 is bent, and the stronger the decal effect is. The pinch angle θ is preferably about 10 degrees or more and 30 degrees or less.

In the printing process using such a thermal transfer printing apparatus TP1, first, the image receiving sheet 7 and the Y layer of the dye layer of the thermal transfer sheet 5 are aligned, and the thermal head 1 is moved to the platen via the image receiving sheet 7 and the thermal transfer sheet 5. Contact the roll 2.

Next, the capstan roller 9 and the collecting unit 4 are rotationally driven, and the image receiving sheet 7 and the thermal transfer sheet 5 are sent to the image receiving sheet roll 6 side and the collecting unit 4 side, respectively. During this period, the area of the Y layer is selectively and sequentially heated by the thermal head 1 based on the image data, and Y is sublimated and transferred from the thermal transfer sheet 5 onto the image receiving sheet 7. The area of the image receiving sheet 7 to which the dye has been transferred passes through the decurling portion D and is decurled.

After sublimation transfer of Y, the thermal head 1 rises and separates from the platen roll 2. Next, the image receiving sheet 7 and the M layer are aligned. In this case, the image receiving sheet 7 is sent to the downstream side by a distance corresponding to the print size, and the thermal transfer sheet 5 is wound around the collecting section 4 by a distance corresponding to the margin between the Y layer and the M layer. Also at this time, the image receiving sheet 7 passes through the decurling portion D to be decurled.

Similar to the method of sublimating and transferring Y, M and C are sequentially sublimated and transferred onto the image receiving sheet 7 based on the image data, and an image is formed on the image receiving sheet 7. Also during this time, the image receiving sheet 7 passes through the decurling portion D to be decurled.

After image formation, the image receiving sheet 7 and the protective layer are aligned with each other, the protective layer is heated by the thermal head 1, and the protective layer is transferred from the thermal transfer sheet 5 onto the image receiving sheet 7 so as to cover the image.

After that, the image receiving sheet 7 on which the image and the protective layer are formed is cut by a cutter to produce a printed matter. Since the decurling section D including the capstan roller 9 and the pinch roller 10 performs the decurling process on the image receiving sheet 7 a plurality of times during the printing process, the image receiving sheet 7 can be effectively decurled. As a result, curl of the printed matter can be suppressed and a high-quality printed matter can be produced.

Further, since the capstan roller 9 and the pinch roller 10 are used for decurling, the device configuration is simple.

(Experimental example)
Experimental example 1
Using the thermal transfer printing apparatus shown in FIG. 1, a protective layer having a glossy surface was formed on the image-receiving sheet, printed sheets were prepared, and the curl amount of the printed sheets was measured.

Image-receiving sheet rolls (image-receiving sheets that have been curled after being stored in a rolled state for a long time) are alternately set on a thermal transfer printing device with a pinch angle θ = 10 degrees and a thermal transfer printing device with a pinch angle θ = 0 degrees. Then, print sheets were produced one by one and the curl amount was measured. The size of the printed sheet was 6 inches×8 inches, and the average amount of curl at the four corners when the printed sheet was placed on a flat surface with the convex side facing downward was taken as the curl amount. As shown in FIG. 4, the pinch angle θ=0 degrees means that the conveyance direction d0 of the image receiving sheet 7 between the printing portion 40 and the decal portion D, the rotation center C1 of the capstan roller 9, and the rotation of the pinch roller 10 are rotated. The state is orthogonal to the direction d2 connecting the center C2.

Experimental example 2
The same as in Experimental Example 1 except that the thermal transfer sheet roll was alternately set to the thermal transfer printing device with the pinch angle θ=15 degrees and the thermal transfer printing device with the pinch angle θ=0° to produce the print sheet. And

Experimental example 3
The same as in Experimental Example 1 except that the thermal transfer sheet roll was alternately set to the thermal transfer printing apparatus with the pinch angle θ=20 degrees and the thermal transfer printing apparatus with the pinch angle θ=0 degrees to produce the print sheet. And

Experimental example 4
Similar to Experimental Example 1 except that the thermal transfer sheet roll was alternately set to the thermal transfer printing device with the pinch angle θ=25 degrees and the thermal transfer printing device with the pinch angle θ=0° to produce the print sheet. And

The measurement results of Experimental Examples 1 to 4 are shown in FIGS. 5A to 5D. It was confirmed that the amount of curl decreases as the pinch angle θ increases. Incidentally, some of the print sheets produced with the pinch angle θ=25 degrees had cracks on the surface. Therefore, in consideration of the curl amount and surface condition of the printed matter, in this experimental example, it was preferable to set the pinch angle θ to 15 degrees or more and 20 degrees or less. It is considered that the preferable range of the pinch angle θ varies depending on the type of the image receiving sheet, the tension of the image receiving sheet, the diameter and material of the capstan roller 9 and the pinch roller 10, the pressure force of the pinch roller 10, the printing speed, and the like.

In the above embodiment, the configuration in which the pinch angle θ is fixed has been described, but the pinch angle θ may be variable. For example, the pinch roller 10 can be moved (rolled) along the outer peripheral surface of the capstan roller 9.

An example of the moving mechanism of the pinch roller 10 is shown in FIG. 6A. The pinch roller 10 is attached to one end of the pinch arm 11, and one end of the spring 12 is connected to the other end. The pinch arm 11 is swingable around a fulcrum shaft 11a, and the tension force of the spring 12 presses the pinch roller 10 against the capstan roller 9.

The pinch roller 10, the fulcrum shaft 11 a of the pinch arm 11 and the other end of the spring 12 are attached to the pinch arm chassis 13. The capstan roller 9 is attached to the pinch arm chassis 13 and the main chassis (not shown). The pinch arm chassis 13 is provided with other members such as a drive motor for rotating the capstan roller 9, but the illustration thereof is omitted.

The pinch arm chassis 13 is rotatable about the rotation axis of the capstan roller 9 by the chassis drive unit 20. The chassis drive unit 20 is a worm gear having a worm wheel (bevel gear) 21 and a worm (screw gear) 23. A groove 22 is formed in the worm wheel 21, and the pin 14 provided at the end of the pinch arm chassis 13 is inserted into the groove 22 to engage the pinch arm chassis 13 and the worm wheel 21.

When the drive motor 24 rotates the worm 23, the worm wheel 21 rotates. When the worm wheel 21 rotates, the pin 14 moves along the groove 22, and the pinch arm chassis 13 rotates counterclockwise around the rotation axis of the capstan roller 9 as shown in FIG. θ changes.

Usually, the smaller the diameter of the image receiving sheet roll, the larger the curl amount of the image receiving sheet. Therefore, it is preferable to control the pinch angle θ to increase as the number of printed images increases and the diameter of the image receiving sheet roll decreases.

6A and 6B, since the pinch roller 10, the pinch arm 11 and the spring 12 move together with the pinch arm chassis 13, even if the pinch angle θ is changed, the pinch pressure of the pinch roller 10 against the capstan roller 9 is changed. Can be constant.

In the above-described embodiment, the image receiving sheet 7 is decurled by using the capstan roller 9 and the pinch roller 10 which are located on the upstream side in the image receiving sheet conveying direction with respect to the image receiving section 40. A roller having a similar mechanism may be provided on the downstream side in the sheet conveying direction to perform decurling.

In the above embodiment, the configuration for reducing the warp of the image receiving sheet has been described, but the same configuration is applied to an apparatus for transferring the transfer layer from the intermediate transfer sheet to the card base material to reduce the warp of the card base material. You can

FIG. 7A is a schematic diagram of a thermal transfer printing apparatus TP2 that transfers the transfer layer TL (see FIG. 8) from the intermediate transfer sheet 150 to a sheet-shaped transfer target 170 such as an IC card and forms an image on the surface of the transfer target 170. It is a figure.

As shown in FIG. 8, the intermediate transfer sheet 150 has a support layer 151, a release layer 152, a protective layer 153, an intermediate layer 154, and a receiving layer/adhesive layer 155. Can be used. The transfer layer TL transferred to the transfer receiving body 170 includes a protective layer 153, an intermediate layer 154, and a receiving layer/adhesive layer 155.

In FIG. 7A, a sending unit that sends out the intermediate transfer sheet 150, a printing unit that transfers a color material from the thermal transfer sheet to the receiving layer/adhesive layer 155 of the intermediate transfer sheet 150 to print an image, and the transferred intermediate transfer sheet 150 are wound. Illustration of a take-up unit, a feeding unit that feeds the transferred bodies 170 one by one, a conveyor device that conveys the fed transfer bodies 170, and the like are omitted.

The intermediate transfer sheet 150 on which the image is formed on the receiving layer/adhesive layer 155 in the printing section is conveyed to the transfer section 100 via the guide roller 108.

The transfer unit 100 includes a heat block 101 and a pressure roll 102 provided below the heat block 101. The heat block 101 is not a rotary type like a heat roller, but has a block shape and has a built-in heater inside, and a block-shaped heating means for pressing and heating an object to be heated, or a built-in heater inside. The heating means is a block-shaped heating means that slides and heats the object to be heated. The transfer unit 100 transfers the transfer layer TL of the intermediate transfer sheet 150 onto the surface of the transfer target 170.

The transfer unit 100 superimposes the receiving layer/adhesive layer 155 surface of the intermediate transfer sheet 150 on which an image is printed on the transfer target 170 between the heat block 101 and the pressure roll 102 and heats the transfer target 170. As a result, the transfer layer TL is transferred to the transfer target 170, and an image is formed on the transfer target 170.

The transferred material 170 on which the image is formed is conveyed and discharged to the discharge portion side on the downstream side while being sandwiched by the first conveying roller 109 and the second conveying roller 110. The first transport roller 109 is a roller that comes into contact with the back surface side of the transfer target 170, that is, the surface opposite to the surface on which the transfer layer TL is transferred. The second transport roller 110 is a roller that comes into contact with the protective layer 153 that is the outermost surface of the transfer layer TL. The transferred body 170 that has passed through the first transport roller 109 and the second transport roller 110 travels while being supported from the back surface side by the guide portion 120.

Here, in the case where the first transport roller 109 and the second transport roller 110 are omitted, the discharged transfer target 170 is heated by the transfer of the transfer layer TL and thermally contracted by the subsequent cooling, as shown in FIG. As described above, the central portion may warp so as to be convex on the back surface side.

Therefore, as illustrated in FIG. 7A, the transfer direction of the transfer target 170 around (in the vicinity of) the printing unit 100, the first transfer roller 109, the second transfer roller 110, and the guide unit 120 is orthogonal to the transfer direction d10. The direction (the first direction perpendicular to the surface of the transferred material 170) is d11, and the direction connecting the rotation center C11 (rotation axis) of the first conveyance roller 109 and the rotation center C12 (rotation axis) of the second conveyance roller 110. Is defined as d12 (second direction), the direction d11 and the direction d12 are non-parallel, the direction d11 and the direction d12 intersect at a constant wrap angle θ′, and the rotation center C12 of the second transport roller 110 becomes It is preferable to dispose the first transport roller 109 and the second transport roller 110 so as to be located farther (away from) the transfer unit 100 than the rotation center C11 of the first transport roller 109.

By arranging the first transport roller 109 and the second transport roller 110 so as to have such a positional relationship, as shown in FIG. 7B, a reverse warp is applied to the transfer target 170, and as shown in FIG. 7C, The transferred material 170 can be made flat. The amount of reverse warpage applied to the transferred body 170 can be controlled by the size of the wrap angle θ′.

When the warp of the transfer target 170 due to heat contraction is opposite to that of FIG. The first transport roller 109 and the second transport roller 110 may be arranged so as to be located closer to the transfer unit 100 than the rotation center C11.

The transfer layer TL need not be transferred from the intermediate transfer sheet 150 to the transfer target 170, and may be, for example, a structure in which the protective layer is transferred from the protective layer transfer sheet to the transfer target 170.

The present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the constituent elements within a range not departing from the gist of the invention in an implementation stage. Further, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above embodiments. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, the constituent elements of different embodiments may be combined appropriately.

1 Thermal Head 2 Platen Roll 3 Supply Section 4 Collection Section 5 Thermal Transfer Sheet 6 Image-Receiving Sheet Roll 7 Image-Receiving Sheet 8 Guide Roller 9 Capstan Roller 10 Pinch Roller 11 Pinch Arm 13 Pinch Arm Chassis 20 Chassis Drive 40 Print Section 100 Transfer Section 101 Heat block 102 Pressure roll 109 First conveyance roller 110 Second conveyance roller 120 Guide section 150 Intermediate transfer sheet 170 Transferred bodies C1, C2, C11, C12 Rotation center (rotation axis)
D Decal portions P1, P2 Pinch point P3 Contact start point d0 Image receiving sheet conveying direction d1 Direction orthogonal to image receiving sheet conveying direction d2 Direction connecting the rotation center of the capstan roller and the rotation center of the pinch roller d10 Transferring body transfer direction d11 Direction orthogonal to the transfer direction of the transferred material d12 Direction connecting the rotation center of the first transfer roller and the rotation center of the second transfer roller θ Pinch angle θ′ Wrap angles TP1 and TP2 Thermal transfer printing apparatus

Claims (8)

An image receiving sheet having an image receiving sheet on the surface is wound, and an image receiving sheet roll for supplying the image receiving sheet,
A thermal head and a platen roll which are provided on the downstream side of the image receiving sheet roll in the image receiving sheet transport direction, and which sandwich the thermal transfer sheet having a color material layer and the image receiving sheet,
A capstan roller and a pinch roller that sandwich and convey the image receiving sheet;
Equipped with
The thermal head heats the thermal transfer sheet to transfer a color material from the thermal transfer sheet to the image receiving sheet,
The thermal transfer printing apparatus, wherein the capstan roller and the pinch roller give the image receiving sheet a warp in a direction opposite to a warp caused by the winding of the image receiving sheet. A first direction orthogonal to the conveyance direction of the image receiving sheet around the thermal head, the platen roll, the capstan roller, and the pinch roller, and a second direction connecting the rotation center of the capstan roller and the rotation center of the pinch roller. 2. The thermal transfer printing apparatus according to claim 1, wherein is not parallel to. The thermal transfer printing apparatus according to claim 2, wherein a pinch angle formed by the first direction and the second direction is 10 degrees or more and 30 degrees or less. The pinch roller moving mechanism for moving the pinch roller along an outer peripheral surface of the capstan roller to adjust a pinch angle formed by the first direction and the second direction, further comprising a pinch roller moving mechanism. The thermal transfer printing apparatus according to item 3. The thermal transfer printing apparatus according to claim 4, wherein the pinch roller moving mechanism moves the pinch roller such that the pinch angle increases as the diameter of the image receiving sheet roll decreases. The location where the image receiving sheet starts to contact the pinch roller when viewed from the thermal head side is closer to the thermal head than the location where the capstan roller and the pinch roller sandwich the image receiving sheet. The thermal transfer printing apparatus according to any one of claims 1 to 5. A transfer sheet having a transfer layer and a sheet-shaped transfer target material are sandwiched, the transfer sheet is heated, and a thermal block and a pressure roll that transfer the transfer layer from the transfer sheet to the transfer target material,
A first transport roller and a second transport roller that sandwich and transport the transfer target to which the transfer layer has been transferred;
Equipped with
A thermal transfer printing apparatus, wherein the first transport roller and the second transport roller impart a warp in a direction opposite to a warp caused by thermal contraction to the transferred body. A first direction orthogonal to the transport direction of the transfer target around the thermal block, the pressure roll, the first transport roller, and the second transport roller, the rotation center of the first transport roller, and the second transport roller. The thermal transfer printing apparatus according to claim 7, wherein the thermal transfer printing apparatus is not parallel to the second direction connecting the center of rotation.

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