JP2019038679A - Thermal transfer printing device - Google Patents

Abstract

To prevent generation of a curl on a printed matter.SOLUTION: A thermal transfer printing device comprises: a printing sheet roll 6 in which a printing sheet 7 having a receiving layer on its surface is wound to feed the printing sheet 7; a thermal head 1 for transferring dye onto the printing sheet 7 from a thermal transfer sheet 5 having a dye layer; a capstan roller 9a and a pinch roller 9b which are provided between the printing sheet roll 6 and the thermal head 1, and pinch the printing sheet 7 to convey; and a decurl part 10 which is provided between the capstan roller 9a and the pinch roller 9b, and the thermal head 1, to impart a warping in an opposite direction to a warping generated by winding of the printing sheet 7, to the printing sheet 7.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a thermal transfer printing apparatus.

  As a method for forming an image, a thermal transfer sheet in which a dye layer is provided on a base material and a printing sheet (thermal transfer image receiving sheet) in which a receiving layer is provided on another base material are overlapped to form an image. The method is known. After the image formation, the print sheet is cut into a desired size to produce a print product. Since the printing sheet before image formation is installed inside the printer in a state of being wound in a roll shape, there is a problem that curling occurs and the printed material after cutting is curled.

Japanese Patent Laid-Open No. 9-30134 JP-A-10-198275

  The present invention has been made in view of the above-described conventional situation, and an object of the present invention is to provide a thermal transfer printing apparatus that prevents curling of a printed matter.

  A thermal transfer printing apparatus according to the present invention includes a printing sheet roll on which a printing sheet having a receiving layer is wound, a thermal sheet for supplying the printing sheet, and a thermal head for transferring the dye from the thermal transfer sheet having a dye layer onto the printing sheet. A capstan roller and a pinch roller that sandwich and convey the print sheet, a capstan roller and a pinch roller, and the thermal head, and the winding of the print sheet around the print sheet And a decurling portion that imparts a warp in a direction opposite to the warp caused by the above.

  In the thermal transfer printing apparatus according to an aspect of the present invention, the capstan roller and the pinch roller are provided between the printing sheet roll and the thermal head.

  In the thermal transfer printing apparatus according to an aspect of the present invention, the decurling unit is provided on the back side of the printing sheet, and includes a decurling guide having a curved convex part that is convex toward the printing sheet, the decurling guide, and the decurling guide And a guide roller provided on the surface side of the printing sheet between the thermal head, and the decal guide is movable in a direction from the back surface of the printing sheet toward the surface.

  In the thermal transfer printing apparatus according to an aspect of the present invention, the decal guide includes a roller that contacts the back surface of the printing sheet.

  In the thermal transfer printing apparatus according to an aspect of the present invention, the thermal transfer sheet has a protective layer, and the amount of movement of the decal guide when the dye is transferred from the thermal transfer sheet onto the printing sheet is determined from the thermal transfer sheet to the print. The amount of movement of the decal guide when the protective layer is transferred onto the sheet is larger.

  In the thermal transfer printing apparatus according to the aspect of the present invention, the capstan roller is in contact with the back side of the printing sheet, the pinch roller is in contact with the front side of the printing sheet, and the decurling guide is moved, The capstan roller moves in a direction away from the decal guide along the outer peripheral surface of the capstan roller.

  The thermal transfer printing apparatus according to the present invention has a printing sheet having a receiving layer wound on its surface, and transfers a dye onto the printing sheet from a printing sheet roll for supplying the printing sheet, and a thermal transfer sheet having a dye layer and a protective layer. A thermal head that forms an image and transfers the protective layer onto the image, a cutter that cuts the printing sheet to produce a printed material, a main conveyance path that conveys the printing sheet to the cutter, A sub-transport path that branches off from the main transport path and transports the print sheet, and is provided in the main transport path or the sub-transport path, and is opposite to the warp caused by the winding of the print sheet with respect to the print sheet. A decurling portion that imparts a warp in the direction, and the decurling portion imparts a warp to the printing sheet before the dye layer and / or the protective layer is transferred.

  In the thermal transfer printing apparatus according to an aspect of the present invention, the decurling unit is provided in the sub-conveying path, and warps the passing printing sheet.

  In the thermal transfer printing apparatus according to an aspect of the present invention, the decurling unit is provided on the main conveyance path, provided on the back side of the printing sheet, and a plate having a curved concave surface that is concave toward the printing sheet side. A roller provided on the surface side of the printing sheet, and the plate or the roller is capable of moving back and forth in a direction perpendicular to the sheet surface of the printing sheet, the plate and the roller The printing sheet is sandwiched to give warpage, and the printing sheet to which the protective layer is transferred does not warp.

  According to the present invention, since the printing sheet is decurled in the vicinity of the printing portion, curling can be prevented from occurring in the printed matter.

1 is a schematic diagram of a thermal transfer printing apparatus according to an embodiment of the present invention. It is the schematic of the decurling part concerning the embodiment. It is a figure which shows an example of a decal process. It is a figure which shows an example of a decal process. It is the schematic of the thermal transfer printing apparatus which concerns on another embodiment. It is the schematic of the thermal transfer printing apparatus which concerns on another embodiment. (A) (b) is the schematic of the decurling part concerning another embodiment.

  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 apparatus includes a thermal transfer sheet in which a yellow (Y) dye layer, a magenta (M) dye layer, a cyan (C) dye layer, and a transferable protective layer (hereinafter referred to as a protective layer) are repeatedly provided in the surface order. 5 is provided with a thermal head 1 that prints an image by sublimation-transferring Y, M, and C onto a printing sheet 7 and forms a protective layer on the image.

  The thermal transfer sheet 5 is fed out from the supply unit 3, passes through the thermal head 1, and is taken up by the collection unit 4. The thermal transfer sheet 5 is conveyed from the supply unit 3 to the collection unit 4 along a plurality of guide rollers 8. As the thermal transfer sheet 5, a known one used in this type of thermal transfer printing apparatus can be used. For example, a material obtained by melting or dispersing a sublimable dye in a binder resin can be used for the dye layer. The protective layer is preferably made of a transparent material having adhesiveness, light resistance and the like.

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

  The printing unit 40 heats the protective layer of the thermal transfer sheet 5 to transfer the protective layer onto the image. By increasing the transfer energy (printing energy by the printing unit 40) when forming the protective layer, the surface of the protective layer becomes a matte tone having a low glossiness, and by reducing the transfer energy, the surface of the protective layer is a glossy tone having a high glossiness. become.

  The printing sheet 7 is fed out from a printing sheet roll 6 obtained by winding the printing sheet 7 in a roll shape. As the printing sheet 7, a known sheet used in this type of thermal transfer printing apparatus can be used. For example, a resin coating 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 a film by adding a void developing agent to PET (polyethylene terephthalate) and peeling PET and the void developing agent in the process of film formation and stretching. As the base material, in addition to PET, polyolefin resins such as PP (polypropylene) and PE (polyethylene) can be used.

  Between the printing unit 40 and the printing sheet roll 6, a rotatable capstan roller 9a for transporting the printing sheet 7 and a pinch roller 9b for pressing the printing sheet 7 against the capstan roller 9a are provided. Is provided. The pinch roller 9 b is a roller that comes into contact with the receiving layer on the surface side of the printing sheet 7. The capstan roller 9 a is a roller that comes into contact with the back side of the printing sheet 7. The printing sheet 7 is conveyed to a predetermined position by the rotation of the capstan roller 9a and the pinch roller 9b that sandwich the printing sheet 7. The pinch roller 9b can move (roll) along the outer peripheral surface of the capstan roller 9a.

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

  As described above, since the printing sheet 7 is loaded in the thermal transfer printing apparatus in a state of being wound in a roll shape, the printing sheet 7 is wrinkled. In the present embodiment, the warp that occurs when the printing sheet roll 6 is wound is upstream of the printing unit 40, specifically, between the capstan roller 9 a and the pinch roller 9 b and the printing unit 40. A decurling unit 10 is provided for imparting a warp in the direction (reverse warping) to the printing sheet 7 and flattening (decaling) the printing sheet 7. In the present embodiment, the printing sheet 7 is wound in a roll shape so that the front surface is on the outer peripheral side and the back surface is on the inner peripheral side.

  The decurling unit 10 includes a decurling guide 11 and a guide roller 12. The decal guide 11 is provided on the back side of the printing sheet 7 and includes a curved convex portion 11a having a curved shape that is convex toward the printing sheet 7 side. The decal guide 11 can advance and retreat along a direction perpendicular to the sheet surface of the printing sheet 7. A roller (not shown) is provided on the curved convex portion 11 a of the decal guide 11. The roller abuts against the back surface of the printing sheet 7 so that the traveling load on the printing sheet 7 is reduced.

  The guide roller 12 is provided on the surface side of the printing sheet 7 between the printing unit 40 and the decal guide 11. The position of the guide roller 12 is fixed.

  When applying reverse warping to the printing sheet 7, the decal guide 11 is moved in the direction from the back surface to the front surface of the printing sheet 7, as shown in FIGS. The printing sheet 7 is bent at the guide roller 12 portion, and a decurling effect can be generated. The greater the amount of movement of the decurling guide 11, the smaller the radius of curvature of the printing sheet 7 at the guide roller 12 (the larger the curvature), and the stronger the decurling effect. FIG. 3 shows an example in which the amount of movement of the decal guide 11 is small, and FIG. 4 shows an example in which the amount of movement is large.

  As the decal guide 11 moves, the pinch roller 9b is moved upstream along the outer peripheral surface of the capstan roller 9a. In other words, the pinch roller 9b is moved away from the decal guide 11. The larger the movement amount of the decurling guide 11, the larger the movement amount of the pinch roller 9b. Thereby, it is possible to prevent the printing sheet 7 from bending between the capstan roller 9a and the pinch roller 9b and the decurling guide 11, and to suppress the tension applied to the printing sheet 7.

  In the printing process using the thermal transfer printing apparatus having such a decurling unit 10, first, the printing sheet 7 and the Y layer of the dye layer of the thermal transfer sheet 5 are aligned, and the thermal transfer sheet 5 and the thermal transfer sheet 5 are used for thermal processing. The head 1 contacts the platen roll 2. Further, the decurling guide 11 and the pinch roller 9b are moved to the positions shown in FIG.

  Next, the capstan roller 9a and the collection unit 4 are driven to rotate, and the printing sheet 7 and the thermal transfer sheet 5 are sent upstream. During this time, the Y layer region 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 printing sheet 7. Due to the heating of the thermal head 1, the temperature of the printing sheet 7 to which the dye has been transferred is high, and the decurling unit 10 performs the decurling more effectively.

  After the sublimation transfer of Y, the thermal head 1 rises and leaves the platen roll 2. Next, the printing sheet 7 and the M layer are aligned. In this case, the printing 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 unit 4 by a distance corresponding to the margin between the Y layer and the M layer.

  In the same manner as the method of sublimation transfer of Y, M and C are sequentially sublimated and transferred onto the printing sheet 7 based on the image data, and an image is formed on the printing sheet 7. During this time, decurling is performed by the decurling unit 10.

  After the image formation, the printing sheet 7 and the protective layer are aligned, the protective layer is heated by the thermal head 1, and the protective layer is transferred from the thermal transfer sheet 5 onto the printing sheet 7 so as to cover the image. At this time, the decurling guide 11 and the pinch roller 9b are moved back to the positions shown in FIG. 3 to weaken the decurling effect. Alternatively, the decurling guide 11 is moved back to the position shown in FIG. Thereby, the finish of the protective layer can be improved without affecting the protective layer transferred to the printing sheet 7.

  Thereafter, the printing 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 unit 10 provided in the vicinity of the printing unit 40 performs the decurling process of the heated printing sheet 7 during the image forming process, the printing sheet 7 can be effectively decurled. As a result, curling of the printed matter can be prevented and a high quality printed matter can be produced.

  In FIG. 2, the decurling guide 11 is shown to be in contact with the back surface of the printing sheet 7 during the non-decaling process, but the decurling guide 11 may be arranged separately from the printing sheet 7.

  FIG. 5 is a schematic configuration diagram of a thermal transfer printing apparatus according to another embodiment of the present invention. The same parts as those in the thermal transfer printing apparatus shown in FIG.

  On the downstream side of the printing unit 40, a main conveyance path 20A for conveying the printing sheet 7 to the cutter 21 by the guide roller 24, the conveyance roller 25, and the like, and a sub conveyance path 20B branched from the main conveyance path 20A are provided. . The cutter 21 cuts the printing sheet 7 to produce a printed product 22. The printed matter 22 is collected on the tray 23.

  In the main conveyance path 20A, a warp in the direction opposite to the warp caused by the winding of the printing sheet roll 6 between the guide roller 24 and the conveyance roller 25 installed on the downstream side of the guide roller 24 (reverse reaction) Is attached to the printing sheet 7, and a decurling portion 30 for flattening (decaling) the printing sheet 7 is fixedly provided.

  The decurling unit 30 includes a roller 31 and a plate 32. The plate 32 is provided on the back side of the printing sheet 7 and includes a curved concave surface 32a having a curved shape that becomes concave toward the printing sheet 7 side.

  The roller 31 is provided on the surface side of the printing sheet 7, and the printing sheet 7 is sandwiched between the roller 31 and the plate 32, and the printing sheet 7 is bent (curved) to generate a decurling effect. Every time the printing sheet 7 passes through the decurling unit 30, the printing sheet 7 is decurled.

  The distance between the thermal head 1 and the decurling unit 30 (conveyance distance of the printing sheet 7) is not particularly limited. For example, one sheet by the decurling operation is set to about 2 to 6 times the diameter of the platen roll 2. The extension of the hit printing time can be minimized as compared with the case where there is no decurling operation. In order to effectively and uniformly decal the entire printing area, it is desirable that the entire printing area of the printing sheet 7 passes through the decurling section 30 and before the start of transfer of each of Y, M, C and protective layers. Alternatively, the conveyance operation of the printing sheet 7 after the transfer is started can be minimized. When this distance is larger than 6 times the diameter of the platen roll 2, it can be said that the distance from the printing portion to the decurling portion is redundant, and the conveyance distance of the printing sheet 7 before transfer of each color becomes unnecessarily long. On the other hand, if the distance is less than twice the diameter of the platen roll 2, the structure of the print portion such as the thermal head may be affected.

  The sub-transport path 20 </ b> B has a transport roller 26 and branches from the main transport path 20 </ b> A on the upstream side of the decurling unit 30, for example, at a position between the guide roller 24 and the decurling unit 30.

  As described above, in the printing process in the printing unit 40, the dye and the protective layer are transferred from the thermal transfer sheet 5 to the printing sheet 7 while the printing sheet 7 and the thermal transfer sheet 5 are sent upstream. Therefore, before transferring the dye and the protective layer, the printing sheet 7 is once drawn downstream from the printing unit 40. At this time, the printing sheet 7 can be decurled by adjusting the drawing amount of the printing sheet 7 and passing it through the decurling unit 30.

  For example, before the yellow dye is transferred, the printing sheet 7 can be decurled by reciprocating once through the decurling unit 30. Similarly, before the magenta dye, the cyan dye, and the protective layer are transferred, the printing sheet 7 can be decurled by reciprocating once through the decurling unit 30. Further, after the protective layer is transferred, the printing sheet 7 can be decurled by passing through the decurling unit 30 when being conveyed to the cutter 21.

  When the printing sheet 7 is not decurled before the dye or the protective layer is transferred, the conveyance path of the printing sheet 7 can be switched to the sub conveyance path 20B so that the decurling unit 30 does not pass.

  The decurling amount of the printing sheet 7 is changed by changing the number of times the printing sheet 7 is pulled out along the main conveyance path 20A and passed through the decurling unit 30, in other words, the number of times the printing sheet 7 is pulled out to the sub conveyance path 20B and not passed through the decurling unit 30. Can be adjusted arbitrarily. Thereby, it is possible to prevent the print product 22 from being curled.

  The number of times the printing sheet 7 passes through the decurling unit 30 is, for example, the printing density, the number of days elapsed from the date of manufacture of the printing sheet roll 6, and where the printing area of the printing sheet 7 is located (the winding diameter). The inner side or the outer side).

  As shown in FIG. 6, the decurling unit 30 may be provided in the sub-transport path 20B. When the printing sheet 7 is decurled before transferring the dye or the protective layer, the printing sheet 7 is pulled out to the side of the sub-transport path 20B and passed through the decurling unit 30. When the decurling is not performed, the printing sheet 7 is pulled out along the main conveyance rate 20 </ b> A so as not to pass through the decurling unit 30.

  When the printing sheet 7 on which the protective layer is formed passes through the decurling unit 30, the surface of the protective layer may be scratched. However, in the configuration shown in FIG. 6, the printing sheet does not pass through the decurling unit 30. 7 can be conveyed to the cutter 21, so that the surface of the protective layer can be prevented from being scratched.

  In the thermal transfer printing apparatus shown in FIG. 5, the configuration in which the position of the decurling unit 30 is fixed has been described. However, the position of the decurling unit 30 may be variable. For example, the plate 32 is configured to be able to advance and retreat along a direction perpendicular to the sheet surface of the printing sheet 7.

  As shown in FIG. 7A, by moving the plate 32 in the direction from the back surface to the front surface of the printing sheet 7, the printing sheet 7 is sandwiched between the roller 31 and the plate 32, and the printing sheet 7 is decurled. it can.

  The plate 32 is moved back to the position shown in FIG. 7B so that the printing sheet 7 does not come into contact with the roller 31 and the plate 32, so that the printing sheet 7 is not decurled.

  Before the transfer of the dye or the protective layer, when the printing sheet 7 is pulled out along the main conveyance path 20A, the plate 32 is moved to the position shown in FIG. 7A, or the position shown in FIG. The decurling amount of the printing sheet 7 can be arbitrarily adjusted by switching between retraction and switching.

  Further, after the transfer of the protective layer, the plate 32 is moved back to the position shown in FIG. 7B to prevent the surface of the protective layer from being scratched.

  The roller 31 may be movable instead of the plate 32.

  In the configuration shown in FIGS. 5 to 7, the guide roller 24 and the conveying rollers 25 and 26 may be rollers with high tension applied to the printing sheet 7, such as capstan rollers (and pinch rollers). Further, the decurling unit 30 may be provided between the thermal head 1 and the guide roller 24.

  The decurling unit 30 may be provided between the printing sheet roll 6 and the capstan roller 9a and the pinch roller 9b. Whether or not the printing sheet 7 passes through the decurling unit 30 can be switched according to the winding amount of the printing sheet 7 during the printing process, and the decurling amount can be adjusted.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

DESCRIPTION OF SYMBOLS 1 Thermal head 2 Platen roll 3 Supply part 4 Collecting part 5 Thermal transfer sheet 6 Printing sheet roll 7 Printing sheet 8 Guide roller 9a Capstan roller 9b Pinch roller 10 Decal part 11 Decal guide 12 Guide roller 20A Main conveyance path 20B Sub conveyance path 21 Cutter 24 Guide rollers 25, 26 Conveying roller 30 Decal section 40 Printing section

Claims (9)

A printing sheet roll on which a printing sheet having a receiving layer is wound and supplying the printing sheet;
A thermal head for transferring a dye from a thermal transfer sheet having a dye layer onto the printing sheet;
A capstan roller and a pinch roller that sandwich and convey the printing sheet;
A decurling unit that is provided between the capstan roller and the pinch roller and the thermal head, and applies a warp in a direction opposite to a warp caused by winding of the print sheet to the print sheet;
A thermal transfer printing apparatus comprising:   The thermal transfer printing apparatus according to claim 1, wherein the capstan roller and the pinch roller are provided between the printing sheet roll and the thermal head. The decal part is
A decal guide provided on the back side of the printing sheet, and having a curved convex part that is convex toward the printing sheet side;
A guide roller provided on the surface side of the printing sheet between the decal guide and the thermal head;
Have
The thermal transfer printing apparatus according to claim 2, wherein the decal guide is movable in a direction from the back surface to the front surface of the printing sheet.   The thermal transfer printing apparatus according to claim 3, wherein the decal guide includes a roller that contacts the back surface of the printing sheet. The thermal transfer sheet has a protective layer,
The amount of movement of the decal guide when transferring the dye from the thermal transfer sheet onto the printing sheet is greater than the amount of movement of the decal guide when transferring the protective layer from the thermal transfer sheet onto the printing sheet. The thermal transfer printing apparatus according to claim 3 or 4, characterized in that: The capstan roller is in contact with the back side of the printing sheet,
The pinch roller is in contact with the surface side of the printing sheet and moves in a direction away from the decal guide along the outer peripheral surface of the capstan roller as the decal guide moves. Item 6. The thermal transfer printing apparatus according to any one of Items 3 to 5. A printing sheet roll on which a printing sheet having a receiving layer is wound and supplying the printing sheet;
A thermal head for transferring a dye from the thermal transfer sheet having a dye layer and a protective layer onto the printing sheet to form an image, and transferring the protective layer on the image;
A cutter that cuts the print sheet to produce a print;
A main conveyance path for conveying the printing sheet to the cutter;
A sub-transport path that branches from the main transport path and transports the printing sheet;
A decurling portion provided in the main conveyance path or the sub-conveyance path, which imparts a warp in a direction opposite to a warp caused by winding of the print sheet to the print sheet;
With
The thermal transfer printing apparatus, wherein the decurling section warps the printing sheet before the dye layer and / or the protective layer is transferred.   8. The thermal transfer printing apparatus according to claim 7, wherein the decurling unit is provided in the sub-conveying path, and warps the passing printing sheet. The decurling unit is provided in the main conveyance path,
A plate having a curved concave surface that is provided on the back surface side of the printing sheet and is concave toward the printing sheet side;
A roller provided on the surface side of the printing sheet;
Have
The plate or the roller is capable of advancing and retreating along a direction perpendicular to the sheet surface of the printing sheet, and imparts a warp by sandwiching the printing sheet between the plate and the roller,
8. The thermal transfer printing apparatus according to claim 7, wherein the printing sheet to which the protective layer is transferred does not warp.

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