JP2009078883A - Printing device - Google Patents

Abstract

To realize a structure capable of accurately rotating and conveying a sheet with a simple and inexpensive structure.
A printing apparatus that sandwiches a print sheet between a driving roller and a driven roller, and performs printing while conveying the print sheet by rotation of the driving roller, wherein a plurality of the driving rollers are provided in a thrust direction. At least one follower roller is provided so as to abut on the plurality of drive rollers, and biasing means for independently biasing the follower roller is provided so that the follower roller presses the drive roller.
[Selection] Figure 1

Description

  The present invention relates to a sheet conveying technique in a printing apparatus.

  For example, the following techniques have been proposed to accurately convey a print sheet in a printer.

  In Patent Document 1, one pinch roller having substantially the same length is provided in one drive roller, and the pinch roller is pressed by a plurality of small rollers, so that the pressure applied to the drive roller by the pinch roller is made uniform, and printing is performed. Corrects dents and distortions in the sheet.

  In Patent Document 2, a plurality of driven rollers are provided side by side with respect to one sheet conveyance driving roller provided at the post stage of the cutter, and a position where the plurality of driven rollers press the print sheet to the driving roller side and a position where it does not press. It can be selected. Thereby, sheet conveyance is enabled by taking over the print sheet from the sheet conveyance drive roller feeding means provided in the preceding stage of the cutter.

In short, the above Patent Documents 1 and 2 are effective for reliably carrying out the sheet conveyance by the drawing operation or the drawing operation because at least one driven roller that applies a uniform pressure to one driving roller is provided. Means.
JP 09-110233 A JP 2007-001317 A

  However, as described above, with a structure in which a driven roller is arranged for one driving roller and a print sheet is sandwiched between the driving roller and the driven roller and conveyed, accurate pulling and pulling operations can be realized. The print sheet cannot be rotated and conveyed.

  In order to rotate and convey the print sheet, it is necessary to rotate the forward and reverse directions by arranging two pairs of driving rollers and driven rollers in the thrust direction (rotating shaft direction) of the driving rollers.

  In the structure in which one driven roller is arranged for one drive roller and the driven roller is pressed by a plurality of small rollers as in Patent Document 1, the support structure of the driven roller and the small rollers becomes complicated, and the printing apparatus Leads to an increase in size and cost.

  Further, in the structure in which a plurality of driven rollers are arranged with respect to one driving roller as in Patent Document 2, there are a plurality of positions of contact of the driven roller with respect to one driving roller when the print sheet is rotated. The rotation center is not stable and the stop position varies.

  Also, if the print sheet is twisted, distorted, warped, etc., the driven roller will be separated from the drive roller, and the print sheet cannot be sufficiently pressed between the drive roller and the driven roller, resulting in variations in the sheet conveyance amount and conveyance direction. Arise.

  Furthermore, when a plurality of driven rollers are held by a single holding member, if the sheet conveying mechanism is warped or deformed, it is sufficient that there is a gap between the driving roller and the driven roller among the plurality of driven rollers. It is separated from the driving roller without being urged by. As a result, the print sheet cannot be sufficiently pressed between the driving roller and the driven roller, resulting in variations in the sheet conveyance amount and conveyance direction.

  A first object of the present invention is to realize a structure capable of accurately rotating and conveying a sheet with a simple and inexpensive structure.

  A second problem is to realize a structure capable of rotating and conveying a sheet without causing variations in the sheet conveyance amount and conveyance direction even when the sheet is twisted, distorted, warped, or the like.

  A third problem is to realize a structure capable of rotating and conveying a sheet without causing variations in the sheet conveyance amount and conveyance direction even when the holding mechanism of the driven roller is warped or deformed. is there.

  In order to solve the above problems, a printing apparatus according to the present invention is a printing apparatus that sandwiches a print sheet between a driving roller and a driven roller, and performs printing while conveying the print sheet by rotation of the driving roller. A plurality of driving rollers are provided in the thrust direction, at least one of the driven rollers is provided so as to contact the plurality of driving rollers, and the driven rollers are independently attached so that the driven roller presses the driving roller. A biasing means was provided.

  According to the present invention, a structure capable of accurately rotating and conveying a sheet with a simple and inexpensive structure can be realized.

  Further, even when the sheet is twisted, distorted, warped, or the like, the sheet can be rotated and conveyed without causing variations in the sheet conveyance amount and conveyance direction.

  Further, even when the holding mechanism of the driven roller is warped or deformed, the sheet can be rotated and conveyed without causing variations in the sheet conveyance amount and conveyance direction.

  Hereinafter, an embodiment according to the present invention will be described in detail with reference to the drawings.

  The embodiment described below is an example for realizing the present invention, and should be appropriately modified or changed according to the configuration of the apparatus to which the present invention is applied and various conditions. The present invention is described below. It is not limited to the embodiment.

[First Embodiment]
FIG. 1 is a cross-sectional view showing a schematic configuration of a printing apparatus according to a first embodiment of the present invention, and shows a state in which one print sheet is separated from a print sheet cassette.

  In FIG. 1, reference numeral 1 denotes a print sheet for transferring ink of a sublimation printer. Reference numeral 2 denotes a print sheet cassette for stacking and holding print sheets. Reference numeral 3 denotes a supply-side bobbin 3a and a take-up bobbin 3b around which the ink ribbon 4 of the sublimation printer is wound. The ink ribbon 4 is appropriately wound from the supply-side bobbin 3a to the take-up bobbin 3b by a motor (not shown).

  Reference numeral 5 denotes a pressure plate that urges the print sheet 1 loaded on the cassette 2 by the elastic member 6 toward the pickup roller (PU roller) 7. The PU roller 7 is inserted into the cassette 2 together with the thermal head 15, rotated in the direction of the arrow by a motor (not shown), and sends the print sheet 1 from the cassette 2. The print sheet 1 sent out from the cassette 2 includes a switchback sub-roller (SBS roller) 10 which is a driven roller rotatably provided on the flapper 9 and a switchback roller (a drive roller provided on the printer main body side). SB roller) 8. Thereafter, by pushing a sheet detection switch 9b provided in the flapper 9, the driving of the PU roller 7 is stopped, and the operation of pulling out the sheet from the cassette 2 is completed.

  The flapper 9 is rotatably supported by the hinge portion 9c and a chassis (not shown). By engaging the flapper pin 9a with the cam 18a provided on the drive lever 18, the position of the flapper 9 and the position of the SBS roller 10 supported by the flapper 9 are determined by the front and rear positions of the drive lever 18. Reference numeral 11 denotes a sheet guide for guiding the printed sheet to be conveyed. Reference numeral 19 denotes a drive member for pushing the drive lever 18, and the position of the drive member 19 is detected by the switches 20 and 21 to determine the position. A spring 23 is installed between the drive lever 18 and the drive member 19. The spring 23 draws the flapper 9 toward the SB roller 8 with the tension, sandwiches the print sheet 1 between the SB roller 8 and the SBS roller 10, and transmits the rotational driving force of the SB roller 8 to the print sheet 1. The print sheet 1 is pulled out, pulled in, and rotated.

  Reference numeral 22 denotes a motor for driving the drive member 19 back and forth. Reference numeral 12 denotes an OB roller that applies a driving force for feeding the print sheet 1 between the thermal head 15 and the platen roller 14, and an OB sub-roller 13 (OBS roller) 13 that is a follower roller at an opposing position is attached by an elastic member. It is installed. A platen roller (PL roller) 14 is urged by an elastic member at a position facing the heat generating portion of the thermal head 15. The platen roller 14 does not have a driving force. Reference numeral 16 denotes a pinch roller (PI roller) that is urged by an elastic member at a position facing a grip roller (GR roller) 17 that is a driving roller.

  The PU roller 7, the SB roller 8, the OB roller 12, and the PL roller 14 are all made of an elastic material such as rubber or elastomer and have a surface frictional force. The SBS roller 10, the OBS roller 13, and the PI roller 16 are made of a rigid body such as metal or resin. A large number of fine and sharp protrusions are formed on the roller surface of the GR roller 17 that abuts against the print sheet 1, and the print sheet 1 is conveyed to the outside together with the PI roller 16 while protruding from the print sheet 1.

  FIG. 2 is a schematic view of the printing apparatus according to the first embodiment of the present invention as viewed from the front, and shows a state in which the print sheet is separated from the cassette.

  In FIG. 2, when the PU roller 7 is driven in the direction of the broken line arrow, the print sheet 1 is separated from the cassette 2 in the direction of the white arrow, and two SB rollers 8 having driving force are provided in the direction of the rotation axis. It is sent out until it hits the specified position. During this time, the SBS roller 10 as a driven roller is separated from the SB roller 8. One SBS roller 10 as a driven roller is disposed at a position facing one SB roller 8 as a driving roller.

  FIG. 3 is a sectional view of the SB roller according to the first embodiment of the present invention.

  The SB roller 8 is fixed to the printer main body so that the center shaft 26 is perpendicular to the sheet separating direction. A first roller shaft 24 having a first SB roller 8 a is rotatably supported on the outer periphery of the central shaft 26, and a second roller shaft 25 having a second SB roller 8 b is disposed on the outer periphery of the first roller shaft 24. And is pivotally supported coaxially. The first roller shaft 24 is provided with a gear portion 24a that receives the driving force, and the second roller shaft 25 is also provided with a gear portion 25a that receives the driving force. The driving force is transmitted from the motor 27 via a gear train (not shown), The rotational speeds of the first SB roller 8a and the second SB roller 8b can be set independently. That is, the first SB roller 8a and the second SB roller 8b can be rotated in the same direction, and the first SB roller 8a and the second SB roller 8b can be rotated in different directions.

  FIG. 4 is a perspective view of main components of the printing apparatus according to the first embodiment of the present invention.

  4A is a perspective view as seen from the front, 28 is a chassis of the printer body, and one flapper 9 is provided for each SBS roller 10. FIG. 4B, the shaft portion 10a of the SBS roller 10 is held in the SBS sub-roller support groove 9d at the tip portion of the flapper 9 so as not to fall off in a rotatable manner. FIG.4 (c) is the perspective view seen from the back surface. The springs 23 are installed one by one on the drive levers 18 provided exclusively for the two flappers 9, respectively, and pull the flapper 9 toward the SB roller (not shown) by the tension of the springs 23 between the springs 23. . In addition, the SBS roller 10 as the driven roller is pressed by the independent urging force for each SB roller 8 as the driving roller. That is, instead of integrating a plurality of flappers 9 having driven rollers, a dedicated flapper 9, a drive lever 18 and a spring 23 are provided for each driven roller for one drive roller, so that the pressing force between the driven rollers can be reduced. We are trying to prevent the impact.

  In this embodiment, since the print sheet 1 is rotated by forward / reverse rotation driving of the two SB rollers 8 which are driving rollers provided in the thrust direction, only one driven roller is opposed to one driving roller. The rotation accuracy is improved. The rotation center of the print sheet 1 is determined by the contact position where the two driving rollers are in contact with each other by the driven roller and the feed speed. That is, when a plurality of driven rollers are pressed against one drive roller, the contact position of the print sheet 1 is not fixed at one place, and thus the sheet rotation center is not determined.

  FIG. 5 corresponds to FIG. 1 and shows a state in which the print sheet is completely separated from the cassette.

  In FIG. 5, the driving member 19 is moved backward in the right direction in the drawing by the driving force of the motor 22. The drive member 19 moves backward, the switch S2 is turned OFF, the switch S3 is turned ON, the motor 22 is stopped, and the drive member 19 is also stopped. Since the drive lever 18 is also pulled by the spring 23, the drive lever 18 moves backward in conjunction with the movement of the drive member 19. The cam 18a provided on the drive lever 18 pulls the flapper pin 9a backward, and the flapper 9 is attracted to the SB roller 8 in the direction of the broken line arrow. The flapper 9 presses the SBS roller 10 against the SB roller 8 with a predetermined urging force by the force of the spring 23 on the print sheet 1 that has been drawn out in advance. At this time, the position of the drive member 19 is determined by the switch S3, the position of the drive lever 18 is determined by the contact of the SB roller 8 and the SBS roller 10, the drive member 19 and the drive lever 18 are separated from each other, and the tension is applied by the spring 23. Will occur.

  Next, the SB roller 8 is rotated in a direction indicated by an arrow by a motor (not shown) for a predetermined time, and the print sheet 1 is completely pulled out from the cassette 2. The rear end of the drawn print sheet 1 descends from the cassette 2 side in the direction sandwiched between the SB roller 8 and the SBS roller 10 toward the print sheet guide 11.

  FIG. 6 is a schematic view of the printing apparatus of FIG. 5 as viewed from the front, and shows a state in which the print sheet is pulled out from the cassette.

  In FIG. 6, when the SBS roller 10 moves in the arrow direction, engages with the SB roller 8, and drives the SB roller 8, the print sheet 1 moves in the white arrow direction and is completely pulled out of the cassette 2.

  FIG. 7 is a cross-sectional view of the printing apparatus according to the first embodiment of the present invention, showing a state in which the print sheet pulled out from the cassette is rotated.

  In FIG. 7, the two left and right SB rollers 8 rotate in the left and right directions at the same rotational speed for a predetermined time to rotate the print sheet 1 pulled out from the cassette 2 around the middle of the left and right SB rollers 8. .

  In the present embodiment, since one SBS roller 10 that applies a dedicated independent urging force to one SB roller 8 that is a driving roller is provided, the rotation center is difficult to shift. This is because the print sheet 1 advances faster when it is far from the rotation center, and when the contact width between the SB roller 8 and the SBS roller 10 is narrowed, the sheet 1 is twisted due to the difference in the amount of sheet advance at the same contact portion due to rotation. This is because it is difficult to occur and the rotation center and rotation stop position are stabilized. The print sheet 1 stops after changing a predetermined amount of rotation angle.

  FIG. 8 is a schematic view of the printing apparatus of FIG. 7 as viewed from the front, and shows a state in the middle of rotating the print sheet.

  In FIG. 8, the right SB roller 8 rotates in the sheet pulling direction, and the left SB roller 8 rotates in the sheet pulling direction. Since the rotational circumferential speeds of the left and right SB rollers 8 are the same and are driven in the opposite directions, the center of rotation is substantially the center of the left and right SB rollers 8. The print sheet 1 rotates counterclockwise as indicated by the white arrow.

  FIG. 9 is a cross-sectional view of the printing apparatus according to the first embodiment of the present invention, showing a state in which a rotated print sheet is drawn into the printer main body.

  In FIG. 9, when the two left and right SB rollers 8 complete the rotation of the print sheet 1 by a predetermined angle, the SB roller 8 is switched to the rotation in the same pull-in direction, and the print sheet 1 is pulled in the printable thermal head direction. To start. Since the print sheet 1 has the rear end of the sheet directed toward the print sheet guide 11 due to the positional relationship between the SB roller 8 and the SBS roller 10, when the SB roller 8 starts pulling in, the print sheet 1 moves along the print sheet guide 11. Sent to the thermal head. Before being sent to the thermal head 15, the print sheet 1 passes between an OB roller 12 that is a driving roller driven by a motor (not shown) and an OBS roller 13 that is a driven roller thereof. Since the rotational speeds on the circumferences of the OB roller 12 and the OBS roller 13 are set to be the same, the print sheet 1 is not kinked or bent by the rotational speed difference.

  The print sheet 1 separated from the SB roller 8 is conveyed by the OB roller 12 that is meshed before separation, passes between the thermal head 15 and the platen roller 14, and is driven by a motor (not shown) ahead of the GR sheet. 17 and PI roller 16 are fed. The transported print sheet 1 has a protrusion provided on the surface of the GR roller 17, and is completely pressed against the GR roller 17 by the PI roller 16, so that the GR roller 17 rotates without sliding from the GR roller 17. It is transported together. Desired thermal energy is applied to the ink ribbon 4 from the thermal head 15 to the print sheet 1 gripped by the GR roller 17, and the ink on the ink ribbon 4 is sublimated and transferred to the print sheet 1 to perform printing. Is called.

  FIG. 10 is a schematic view of the printing apparatus of FIG. 9 as viewed from the front, and shows a state where the printing apparatus is retracted after the print sheet is rotated. Both the left and right SB rollers 8 are driven at the same circumferential rotational speed in the sheet pull-in direction, and the print sheet 1 is pulled into the printer main body as indicated by a white arrow.

[Second Embodiment]
FIG. 11 is a perspective view of main components of the second embodiment according to the present invention.

  FIG. 11A is a perspective view seen from the front. Reference numeral 28 denotes a printer chassis and one flapper 9, which has two SBS rollers 10. As shown in an enlarged view in FIG. 11 (b), the shaft portion 10a of the SBS roller 10 is held in the SBS sub-roller support groove 9e at the tip of the flapper 9 so that the shaft portion 10a can rotate and move in the direction of the SB roller. Has been.

  In the state where the SB roller 8 and the SBS roller 10 are separated from each other, corresponding to FIG. 1, the SBS roller 10 is urged toward the SB roller 8 side by the torsion spring 30 in the flapper 9 and does not come out of the flapper 9. Is held so.

  In a state corresponding to FIG. 5 where the SB roller 8 and the SBS roller 10 are in contact with each other, the position of the flapper is determined by pressing the flapper 9 against a flapper receiving portion (not shown) by the urging force of the spring 23. Further, the SBS roller 10 contacts the SB roller 8 to charge the torsion spring 30 in a direction away from the SB roller 8 from the state of FIG. 1, and presses the SBS roller 10 against the SB roller 8 with a desired urging force. Stop.

  The SBS roller 10 is constructed so that one torsion spring 30 urges the SBS roller 10 in the SB roller direction for each shaft portion 10a of the SBS roller 10. The flapper 9 has drive pins 9f fitted to cam portions 29a of the drive lever 29 having two support portions, and the drive lever 29 is moved back and forth by opening and closing the flapper 9. Since the movement of the flapper 9 is the same as that of the first embodiment, description thereof is omitted.

As described above, since the SBS roller 10 provided with a plurality of independent urging means is arranged for each SB roller as the driving roller, the flapper 9 as the SBS roller holding means has minute distortion and warpage on the parts. Also, the amount of bias by each torsion spring is adjusted.
That is, the slight positional deviation of the SBS sub-roller support groove 9e with respect to the SB roller 8 with respect to the SB roller 8 has a small variation in the generated force when converted to the angular deviation of the spring 30. The deviation is eliminated. In addition, variations in sheet conveyance amount and conveyance direction are reduced.

  FIG. 11C is a perspective view seen from the back. Two springs 23 are mounted on the drive lever 29, and the flapper 9 is pulled toward the SB roller 8 (not shown) between the drive members 19 by the tension of the spring 23. Each SB roller 8 that is a driving roller presses the SBS roller 10 that is a driven roller with an independent urging force. That is, while the cost of the flapper 9 having driven rollers is reduced, a dedicated torsion spring 30 is provided for each driven roller facing one drive roller, so that the pressing force of each driven roller is affected. I am trying not to.

  The rotation center of the print sheet 1 is determined by the contact position where the two driving rollers are in contact with each other by the driven roller and the feed speed. That is, when a plurality of driven rollers are engaged with one drive roller, the contact position of the print sheet 1 is not fixed at one place, and the sheet rotation center is not determined. In the present embodiment, since the print sheet 1 is rotated by forward / reverse rotation driving of the SB roller 8 as two driving rollers, only one driven roller is opposed to one driving roller to improve the rotation accuracy. .

  According to the above embodiment, the driven roller is independently urged for each driving roller, so that even if the sheet is twisted, distorted, warped or the like during sheet rotation, the driven roller is driven with respect to the sheet position. The followability of the roller is improved. That is, even if any one of the driven rollers moves in accordance with the sheet shape, the other driven rollers do not move together.

  In addition, even if there is some distortion of parts, the driven roller is urged independently for each driving roller, so that the urging force of one driven roller does not change depending on the position of the other driven roller and is stable. Sheet pressing can be realized. For this reason, since the frictional force of the driving roller to the sheet is also stabilized, the sheet can be pulled out, pulled in, and rotated with high accuracy.

  Further, instead of providing a plurality of driven rollers for one driving roller as in the prior art, basically one driven roller is urged independently from one driving roller. Can be easily determined, and the sheet rotation drive can be stabilized.

  Also, when the driven roller is not nipped from the driving roller, the driving roller and the driven roller are separated from each other. The end position is accurate. Further, the support state of the print sheet is changed by the nip operation of the driven roller, and the print sheet conveyance direction can be changed.

1 is a cross-sectional view illustrating a schematic configuration of a printing apparatus according to a first embodiment of the present invention. It is the schematic diagram which looked at the printing apparatus of FIG. 1 from the front. It is sectional drawing of the SB roller of 1st Embodiment. 1 is a perspective view of main components of a sheet conveying apparatus according to a first embodiment of the present invention. 1 is a cross-sectional view illustrating a schematic configuration of a printing apparatus according to a first embodiment of the present invention. It is the schematic diagram which looked at the printing apparatus of FIG. 5 from the front. 1 is a cross-sectional view illustrating a schematic configuration of a printing apparatus according to a first embodiment of the present invention. It is the schematic diagram which looked at the printing apparatus of FIG. 7 from the front. 1 is a cross-sectional view illustrating a schematic configuration of a printing apparatus according to a first embodiment of the present invention. It is the schematic diagram which looked at the printing apparatus of FIG. 9 from the front. It is a perspective view of the main components of the sheet conveying apparatus of the second embodiment according to the present invention.

Explanation of symbols

1 Print Sheet 2 Cassette 3 Bobbin 4 Ink Ribbon 5 Pressure Plate 6 Elastic Member 7 Pickup Roller (PU Roller)
8 Switchback roller (SB roller)
9 Flapper 10 Switchback sub roller (SBS roller)
11 Print sheet guide 12 OB roller 13 OB sub roller (OBS roller)
14 Platen roller (PL roller)
15 Thermal head 16 Pinch roller (PI roller)
17 Grip roller (GR roller)
18 drive lever 19 drive member 20 switch 21 switch 22 motor 23 spring 24 first roller shaft 25 second roller shaft 26 central shaft 27 motor 28 chassis 29 drive lever 30 torsion spring

Claims (5)

A printing apparatus that sandwiches a print sheet between a drive roller and a driven roller, and prints while conveying the print sheet by rotation of the drive roller,
A plurality of the driving rollers are provided in the thrust direction,
At least one follower roller is provided so as to contact the plurality of drive rollers;
A printing apparatus, comprising: an urging unit that urges the driven roller independently so that the driven roller presses the driving roller.   The printing apparatus according to claim 1, wherein the plurality of driving rollers are supported by driving means capable of independently setting a rotation speed.   3. The printing apparatus according to claim 1, wherein the driven roller includes a moving unit that moves between a position in contact with the driving roller and a position separated from the driving roller.   The printing apparatus according to claim 3, wherein the urging unit urges the moving unit with a spring.   The printing apparatus according to claim 1, wherein the print sheet is rotated and conveyed by rotating the driving roller.