JP2018083295A - Printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such the problem that it is difficult for a printer that transports a sheet with a transportation belt to maintain sheet transportation performance while stably holding print quality.SOLUTION: In a printer, a platen (112) provided on an inner peripheral side of an endless transportation belt (113) looped across a plurality of rollers (114, 115) is configured so as to be movable to a first position where the transportation belt is held between a thermal head (110) and the platen and a second position separated apart from the thermal head. The printer is configured so that the transportation belt protrudes on a side of the thermal head when the platen is positioned in the first position.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a printer that prints using a thermal head, and more particularly to a printer that conveys a sheet by a conveyance belt.

  In recent years, printers for easily obtaining printed matter from image data obtained with a digital camera or the like have become widespread.

  Conventionally, as one of these printers, a thermal transfer recording method using a thermal head has been used as a method for obtaining high-quality image recording with a simple structure. In a printer using a thermal transfer recording method, a configuration in which recording is performed while a recording sheet is conveyed by a roller is generally used. However, a configuration in which a recording sheet is conveyed by a belt has been proposed, and an example thereof is Patent Document 1. .

  As described in Patent Document 1, a great advantage of performing recording while conveying a recording sheet with a belt is that recording can be performed without a margin from the beginning to the rear end in the conveying direction of the recording sheet. In Patent Document 1, a platen is disposed at a position facing a thermal head, and an ink ribbon in which a dye is previously applied to a film-like ribbon and a recording sheet are sandwiched between the thermal head and the platen. In the thermal head, a plurality of heating elements (resistance elements) are arranged in a line. By selectively energizing the heating element of the thermal head while conveying the recording paper with the belt, the dye applied to the ink ribbon is transferred to the recording paper, and printing is performed. In particular, in a thermal transfer recording type printer that performs full-color printing, yellow (Y) applied in sequence to the ink ribbon is printed, and the recording paper is conveyed in the reverse direction to the printing start position, and then magenta (M) is overprinted. Thereafter, a full color image can be printed by superimposing cyan (C) with the same operation.

JP 2009-178965 A

  In Patent Document 1, the belt forms a substantially horizontal conveyance path with respect to the thermal head. However, due to variations in the accuracy of each component, the belt is actually not a complete horizontal conveyance path with respect to the thermal head, but has a concave shape or a convex shape with respect to the thermal head.

  If the belt has a concave shape at the pressure contact between the thermal head and the platen due to variations in component accuracy, the thermal head will bite into the recording paper. In this case, an excessive amount of heat is applied to the recording paper, and there is a high possibility that the ink ribbon sticks to the recording paper and thermal damage to the surface of the recording paper occurs.

  Conversely, if the belt has a convex shape due to the pressure contact between the thermal head and the platen due to variations in component accuracy, the recording paper may be separated from the belt starting from the convex portion when transporting the recording paper. . If the recording paper is transported away from the belt, the leading edge of the recording paper collides with the pressure contact roller that presses the recording paper against the conveying belt, and the leading edge of the recording paper is broken or a paper jam occurs. there's a possibility that.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a printer that transports paper by a transport belt and suppresses the occurrence of paper jam while maintaining stable print quality.

In order to achieve the above object, a printer of the present invention is a printer that performs printing by sandwiching a sheet by a thermal head and a platen,
A plurality of rollers including a drive roller;
A transport belt for transporting paper, an endless transport belt stretched around a plurality of rollers;
A thermal head provided on the outer peripheral side of the conveyor belt;
A platen provided on the inner peripheral side of the conveyance belt, and configured to be movable between a first position where the conveyance belt is sandwiched between the thermal head and the platen and a second position where the conveyance belt is separated from the thermal head. The platen,
A pressure roller disposed on the outer peripheral side of the conveyor belt and in contact with the conveyor belt, the pressure roller provided upstream and downstream in the printing direction of the thermal head;
Tension applying means for applying tension to the conveyor belt,
When the platen is in the first position, the conveyance belt is configured to protrude toward the thermal head.

  According to the present invention, when the platen is in the first position, the sheet can be stably brought into contact with the heating element of the thermal head, so that a good print can be realized. Further, when the platen is in the second position, the leading edge of the paper does not collide with the pressure roller, and therefore, the occurrence of paper jam can be prevented.

External perspective view of printer Sectional drawing explaining the printing operation of a printer The figure which shows the flowchart of the printing operation of the printer Sectional view explaining operation of tension roller

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  The printer according to the present invention will be described below with reference to FIGS.

  FIG. 1 is an external perspective view of a printer according to an embodiment of the present invention. As shown in FIG. 1, 100 is a printer, 200 is an ink ribbon cassette, and 300 is a paper tray. On the side surface of the printer 100, there is an ink ribbon cassette insertion port 101 for allowing the ink ribbon cassette 200 to be mounted. The ink ribbon cassette 200 is detachable in the direction of arrow A. A front side of the printer 100 has a paper tray insertion slot 102 for allowing the paper tray 300 to be mounted. The paper tray 300 can be attached and detached in the direction of arrow B.

  Reference numeral 103 denotes a display unit, 104 denotes a power button, 105 denotes a menu button, 106 denotes a selection button, and 107 denotes a print button, which are arranged on the top surface of the printer 100. The display unit 103 includes display means such as an LCD, and can display an image to be printed, image processing information, and the like on the display unit 103. The power button 104 can turn on / off the power of the printer 100, and the menu screen of the printer 100 can be displayed on the display unit 103 by pressing the menu button 105. The selection button 106 can select an item or an image on the menu screen displayed on the display unit 103. By pressing the print button 107, an image displayed on the display unit 103 can be printed.

  FIG. 2 is a cross-sectional view for explaining the printing operation of the printer 100. 2A is a cross-sectional view showing the state when the paper 301 is fed, FIG. 2B is a cross-sectional view showing the state where the paper 301 is at the print start position, and FIG. 2C is a view when the print is started. FIG. 2D is a cross-sectional view showing a state during printing.

  As shown in FIG. 2A, 110 is a thermal head, 111 is a heat sink, and 112 is a platen. The thermal head 110 is attached to the heat radiating plate 111 and is fixedly held by the printer 100 so that the heat generated by the thermal head 110 can be transferred to the heat radiating plate 111. The platen 112 is movable by being transmitted power from a drive source (not shown) from the position shown in FIG. 2A to the position shown in FIG. 2C, and a pressure contact force is generated between the thermal head 110 and the platen 112. Can be generated.

  Reference numeral 113 denotes a belt, 114 denotes a driving roller, 115 denotes a driven roller, 116 denotes a pressure contact roller, and 117 denotes a tension roller. The conveyor belt 113 is an endless belt, is stretched over the drive roller 114 and the driven roller 115, and is further disposed so as to pass between the thermal head 110 and the platen 112. The conveyance belt 113 has a width dimension orthogonal to the conveyance direction of the recording paper 301 larger than the length of the heating element of the thermal head 110. The driving roller 114 is transmitted with power from a driving source (not shown) and can rotate in forward and reverse directions, and can contact the inner peripheral surface of the conveying belt 113 to drive the conveying belt 113. The driven roller 115 is provided on the inner peripheral side so as to come into contact with the inner peripheral surface of the conveyor belt 113, supports the conveyor belt 113, and can be driven to rotate by the conveyor belt 113 driven by the driving roller 114. it can. In this embodiment, three driven rollers 115a, 115b, and 115c are arranged, but the present invention is not limited to this. For example, two or four may be used.

  The pressure roller 116 is provided on the outer peripheral side so as to contact the outer peripheral surface of the belt, and is rotatably supported by the printer 100. The pressure roller 116 can be rotated by being driven by the conveyance belt 113 so that the recording paper 301 is brought into close contact with the conveyance belt 113 and the recording paper 301 can be conveyed in accordance with the driving of the conveyance belt 113. In this embodiment, four pressure rollers 116a, 116b, 116c, and 116d are arranged, but the present invention is not limited to this. For example, three or five may be used.

  The tension roller 117 is in contact with the outer peripheral surface of the conveyor belt 113 and is supported so as to release the slack generated in the conveyor belt 113 and apply tension to the conveyor belt 113 by urging the conveyor belt 113. Details will be described later.

  118 is a paper feed roller, 119 is a paper discharge roller, 120 is a pressure plate, and 121 is a paper guide. The paper feed roller 118 can be driven to rotate by a paper feed drive motor (not shown). The paper discharge roller 119 is a driven roller that faces the paper feed roller 118, and is configured to rotate following the rotation of the paper feed roller 118. The pressure plate 120 is rotationally driven by a drive source (not shown) and is configured to be rotatable from the position shown in FIG. 2B to the position shown in FIG. The paper guide 121 is rotatably supported from the position shown in FIG. 2B to the position shown in FIG. Further, the paper guide 121 is always urged downward and is in the position shown in FIG.

  Next, the printing operation of the printer 100 will be described with reference to FIGS. FIG. 3 is a flowchart illustrating the printing operation of the printer 100.

  When the printer 100 receives a print instruction, as shown in FIG. 2A, the pressure plate 120 is rotationally driven by a driving source (not shown), and the paper 301 stored in the paper tray 300 comes into contact with the paper feed roller 118. . The paper 301 is fed from the paper tray 300 by the paper feed roller 118 being rotated by a paper feed drive source (not shown). At this time, the front end of the paper 301 abuts on the paper separation unit 122, so that only one of the outermost paper 301 can be separated and fed. The sheet 301 is conveyed while pushing up the sheet guide 121.

  When the leading end of the paper 301 in the paper feeding direction is conveyed to the front of the pressure roller 116a, the driving roller 114 is driven, and the conveying belt 113 rotates clockwise in the drawing. The paper 301 is conveyed in the direction of arrow C in the figure following the rotation of the conveying belt 113 by being pressed and held by the pressing roller 116a and the conveying belt 113. When the sheet 301 is conveyed in the direction of arrow C in the figure, it is held in pressure contact with the pressure rollers 116b, 116c, 116d and the conveying belt 113 and conveyed to the print start position shown in FIG. 2B (S1). 2A and 2B, the platen 112 is in the standby position. At the standby position, the platen 112 is not in contact with the transport belt 113 and is in a state of being separated from the thermal head 110, and therefore printing by the thermal head cannot be performed. However, the ink ribbon 201 and the paper 301 can be transported with a transport load that is less than the state in which the thermal head 110 and the platen 112 are pressed against each other. Since the platen 112 is not in contact with the conveyance belt 113, the conveyance belt 113 is not bent between the pressure rollers 116c and 116b located upstream and downstream in the printing direction near the thermal head 110, respectively. Therefore, the sheet 301 does not collide with the pressure rollers 116b and 116c, and the leading end of the sheet 301 is bent so that the sheet is not jammed. Further, the pressure rollers 116b, 116c, and 116d are held at a substantially horizontal position in contact with the conveyor belt 113. Therefore, the sheet 301 does not collide with the pressure rollers 116b, 116c, and 116d, and the leading end of the sheet 301 is bent so that the sheet is not jammed.

  Next, when the sheet 301 is conveyed to the printing start position shown in FIG. 2B, yellow printing is started in order to perform desired printing (S2). First, the platen 112 is moved in the direction of arrow E from the standby position shown in FIG. 2B to the printing position as shown in FIG. By moving the platen 112 to the printing position, the paper 301 conveyed by the conveying belt 113 can be nipped between the thermal head 110 and the platen 112 for printing. As the platen 112 moves, the conveyor belt 113 also moves. When the platen 112 is in the printing position, the conveyor belt 113 between the pressure rollers 116b and 116c forms a convex shape that apex of the nip position between the platen 112 and the thermal head 110, and the conveyor belt 113 is the thermal head. Protrudes to the side. Therefore, the conveyor belt 113 is wound around the pressure rollers 116b and 116c, and the contact area is increased. When the contact area between the pressure rollers 116a and 116c and the conveying belt 113 is increased, the area in which the sheet 301 is pressed against the conveying belt 113 by the pressure rollers 116a and 116c is increased. In other words, since the area where the paper 301 is pressed against the transport belt 113 becomes large during printing, the transport force by the transport belt 113 can be increased. Therefore, even when a large transport load is generated at the pressure contact between the thermal head 110 and the platen 112, the occurrence of transport misalignment or the like can be suppressed.

  Further, the tension of the conveyor belt 113 that occurs with the movement of the platen 112 applies tension to the conveyor belt 113 by the tension roller 117 moving in the directions of arrows E and F so that no significant change in tension occurs. Yes.

  Details will be described with reference to FIG. 4A and 4B are cross-sectional views for explaining the operation of the tension roller. FIG. 4A is a cross-sectional view at the standby position, and FIG. 4B is a cross-sectional view at the printing position.

  As shown in FIG. 4A, the tension roller 117 is supported by the tension roller arm 130 from the position shown in FIG. 4A to the position shown in FIG. Yes. The tension roller arm 130 is always urged in the direction of arrow G by the tension spring 131. That is, the tension roller 117 disposed on the outer periphery of the conveyance belt 113 is urged toward the conveyance belt 113 side. Since the tension roller 117 is disposed on the outer peripheral side of the conveying belt 113 and is urged toward the conveying belt 113, the tension roller 117 moves to the inner peripheral side, and the enlargement of the apparatus can be prevented.

  When the tension roller 117 moves from the standby position shown in FIG. 4A to the printing position shown in FIG. 4B, the tension spring 131 is extended, so that the urging force against the tension arm 130 is increased. That is, the urging force of the tension roller 117 to the conveyor belt 113 is larger at the printing position than at the standby position, and the tension generated on the conveyor belt 113 is also increased. Therefore, it is possible to suppress the occurrence of looseness or the like on the conveyor belt 113 even when the conveyance resistance is generated at the pressure contact portion between the thermal head 110 and the platen 112 during printing.

  When the platen 112 moves to the printing position shown in FIG. 2C, the driving roller 114 is rotated counterclockwise so that the sheet 301 passes under the thermal head 110, and the conveying belt 113 is counterclockwise. The paper 301 is conveyed in the direction of arrow D in the figure.

  In this embodiment, the driving roller 114 is disposed downstream of the pressure contact between the thermal head 110 and the platen 112 in the printing direction. When a large conveyance load is generated at the pressure contact between the thermal head 110 and the platen 112, the tension generated on the conveyance belt 113 between the driving roller 114 and the pressure contact between the thermal head 110 and the platen 112 becomes the pulling direction, and the conveyance belt 113. Can be prevented.

  Then, the heating element of the thermal head 110 generates heat by a printing signal supplied from a control device (not shown) in accordance with the conveyance of the paper 301, and the yellow dye on the ink ribbon 201 is thermally transferred to the paper 301 to perform yellow printing. At this time, the take-up bobbin 203 is driven to rotate counterclockwise in the drawing by a driving source (not shown), and the ink ribbon 201 performs yellow printing while winding in the arrow D direction in the drawing at substantially the same conveyance speed as the paper 301.

  When the paper 301 is conveyed to the position shown in FIG. 2D, the leading edge of the paper 301 is guided by the pressure roller 116b, and the paper 301 is pressed by the pressure roller 116b and the conveyor belt 113. Further, since the pressure roller 116b is positioned in the vicinity of the thermal head 110, the leading end of the paper 301 abuts below the rotation center of the pressure roller 116b, and the paper 301 is reliably guided between the pressure roller 116a and the conveyance belt 113. can do.

  Further, yellow printing is continued while the sheet 301 is further conveyed in the direction of arrow D. When yellow printing is completed, the return operation is performed to perform the next magenta printing. After printing, the platen 112 is first moved to the standby position shown in FIG. Next, the driving roller 114 is driven to rotate the conveying belt 113 clockwise in the drawing, and the sheet 301 is conveyed in the direction of arrow C in the drawing to the printing start position shown in FIG. 2B (S3).

  At the same time, in order to perform the next magenta printing in the ink ribbon cassette 200, the winding bobbin 203 is rotated so that the magenta printing start position of the ink ribbon 201 is aligned with the position facing the thermal head 110, and the ink ribbon 201 is supplied to the supply bobbin 202. Pull out from.

  When the paper 301 is conveyed to the printing start position and the magenta printing start position of the ink ribbon 201 is cued, the return operation is completed and magenta printing is started (S4).

  Magenta printing is performed in the same manner as the yellow printing described above. That is, the platen 112 is moved from the standby position shown in FIG. 2B to the printing position shown in FIG. Then, the conveyance belt 113 is rotated counterclockwise in the figure so that the sheet 301 is conveyed while being sandwiched between the thermal head 110 and the platen 112, and the sheet 301 is conveyed in the direction of arrow D in the figure. At this time, the heating element of the thermal head 110 generates heat, and the magenta dye on the ink ribbon 201 is thermally transferred to the paper 301 to perform magenta printing. At this time, the ink ribbon 201 is taken up by the take-up bobbin 203 as in the case of yellow printing.

  Thereafter, the cyan printing is performed after the return operation (S5) is performed in the same manner as the yellow printing and magenta printing described above regarding the cyan printing (S6).

  The printer 100 according to the present embodiment performs overcoat printing in order to reduce the deterioration of the image printed on the paper 301 due to an external factor after performing three-color printing. As with the yellow, magenta, and cyan prints, the overcoat print is performed after the return operation (S7) and then the overcoat print (S8).

  When the overcoat printing is finished, the platen 112 is moved in the direction of arrow F by a drive source (not shown), and is stopped at the position shown in FIG. Then, in order to discharge the paper 301, the transport belt 113 and the paper feed roller 118 are rotated counterclockwise in the figure, the paper 301 is transported in the direction of arrow D, and the paper 301 is discharged outside the printer 100 (S9). ) Complete printing.

  Although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

DESCRIPTION OF SYMBOLS 100 Printer 110 Thermal head 111 Heat sink 112 Platen 113 Belt 114 Drive roller 115 Drive roller 115 Press roller 117 Tension roller 118 Paper feed roller 119 Paper discharge roller 120 Pressure plate 121 Paper guide 122 Separating part 200 Ink ribbon cassette 201 Ink ribbon 202 Supply bobbin 203 Winding bobbin 300 Paper tray 301 Paper

Claims (9)

A printer that prints by sandwiching paper between a thermal head and a platen,
A plurality of rollers including a drive roller;
A transport belt for transporting paper, an endless transport belt stretched around the plurality of rollers;
A thermal head provided on the outer peripheral side of the conveyor belt;
A platen provided on the inner peripheral side of the transport belt, and is movable to a first position where the transport belt is sandwiched by the thermal head and the platen, and a second position which is separated from the thermal head A platen configured to
A pressure contact roller disposed on an outer peripheral side of the transport belt and in contact with the transport belt, the pressure contact rollers provided respectively upstream and downstream in the printing direction of the thermal head;
Tension applying means for applying tension to the conveyor belt,
The printer is configured such that when the platen is in the first position, the conveyor belt protrudes toward the thermal head.   2. The printer according to claim 1, wherein when the platen moves to the second position, the tension applying unit eliminates the looseness of the transport belt caused by the movement of the platen.   2. The printer according to claim 1, further comprising a control unit that moves the platen to the first position during printing by the thermal head, and moves the platen to the second position after printing.   The printer according to claim 3, wherein the control unit moves the platen to the second position when the sheet is conveyed by the conveyance belt without printing by the thermal head.   The printer according to claim 1, wherein the second position is a position where the platen does not come into contact with the transport belt.   The contact area between the pressure roller and the conveyance bell is configured to be larger when the platen is at the first position than when the platen is at the second position. The printer according to claim 1.   The printer according to claim 1, wherein the driving roller is disposed on the downstream side in the printing direction. The tension applying means has an urging means for applying tension to the transport belt,
The biasing means is configured so that a biasing force when the platen is in the first position is larger than that when the platen is in the second position. The printer according to 1.   The tension applying unit includes a tension roller disposed on an outer peripheral side of the conveyor belt, and an urging unit that urges the tension roller toward an inner peripheral side of the conveyor belt. The printer according to claim 8.