JP4538059B2 - Ribbon feeder - Google Patents

Description

  The present invention relates to a ribbon supply device that supplies an ink ribbon to a printing unit of a thermal transfer thermal transfer thermal printer, and more particularly to a ribbon supply device used in a thermal transfer thermal printer that performs backfeed.

  A platen roller having a platen roller and a thermal head arranged such that a surface on which a plurality of heating elements are formed in the width direction is opposed to the platen roller, and a print medium and an ink ribbon overlap each other In thermal transfer thermal printers, which are printed by being sandwiched between the thermal head and the thermal head, a ribbon supply shaft that is mounted in a state in which an unused ink ribbon is wound in a roll, and a platen roller A ribbon supply device including a ribbon take-up shaft that is driven to rotate is used. The ink ribbon is bridged between the ribbon supply shaft and the ribbon take-up shaft so as to pass through the printing unit, and after transfer, By winding the ink ribbon with the ribbon take-up shaft, the ink ribbon drawn from the ribbon supply shaft is supplied to the printing unit.

  In general, in a thermal transfer type thermal printer having such a configuration, after the printed medium to be printed is ejected, back feed is performed to return the unprinted leading end portion of the medium to be printed to the print position of the thermal head to supply the ribbon. The ribbon supply shaft of the apparatus is provided with a ribbon rewinding mechanism that rewinds the ink ribbon using the biasing force of the torsion coil spring during back feed (for example, see Patent Document 1).

  However, there are two methods for winding the ink ribbon mounted on the ribbon supply shaft: the front winding method in which the thermal transfer surface is exposed on the surface of the roll, and the reverse winding method in which the thermal transfer surface is located on the inner side of the roll. When rewinding with a single ribbon unwinding mechanism for an ink ribbon wound by either the winding method or the reverse winding method, the direction of rotation is opposite in each method, so the ribbon supply Only the rewind amount corresponding to the rotation angle up to approximately half the axis (approximately 180 degrees) of the shaft can be obtained, and the rewind amount for rewinding the ink ribbon to the ribbon supply shaft is limited at the time of back feed, and the thermal transfer type Depending on the configuration of the thermal printer, there is a problem that the amount of rewinding of the ink ribbon is insufficient.

Japanese Patent Laid-Open No. 05-57978

  The present invention has been made in view of such a problem, and the object of the present invention is to provide a single ribbon ribbon that is wound on either the front winding method or the back winding method. The object of the present invention is to provide a ribbon supply device that can secure a large winding amount by using one ribbon rewinding mechanism.

In order to solve the above problems, the present invention has the following configuration.
The gist of the invention described in claim 1 includes a ribbon supply shaft that is mounted in a state in which an unused ink ribbon is wound in a roll shape, and a ribbon take-up shaft that is rotationally driven in conjunction with a platen roller. A ribbon supply device that pulls out the unused ink ribbon from the ribbon supply shaft by winding the used ink ribbon on the ribbon take-up shaft, and is arranged in parallel with the ribbon supply shaft. A rewinding rotation shaft, a small gear provided on the ribbon supply shaft, and a large gear provided on the rewinding rotation shaft, and the ribbon supply shaft and the rewinding rotation shaft by the small gear and the large gear, The rotation force of the rewinding rotation shaft transmitted in the opposite direction by the rotation of the rewinding rotation shaft transmitted from the ribbon supply shaft by the small gear and the large gear is transmitted. ; And a biasing force storing means for product, the biasing force storage means is
A torque limiter that controls rotation transmission to the rotating member loosely mounted on the rewinding rotating shaft, a stopper pin that regulates any direction of the rotating member at about 180 degrees, and rotation of the rotating member A ribbon spring for storing a biasing force, and transmitting the rotation of the rewinding rotary shaft based on the biasing force stored in the coil spring to the ribbon supply shaft with an increased amount of rotation. Exist.
According to a second aspect of the present invention, there is provided a small gear that is mounted on the ribbon supply shaft, and a large gear that is mounted on the rewinding rotary shaft and meshed with the small gear. 2. The ribbon feeder according to claim 1, wherein the ratio of the gear to the large gear is set to 1: 2.

The ribbon supply device of the present invention includes a rewind rotary shaft arranged in parallel with the ribbon supply shaft, a rotation transmission means for transmitting the rotation between the ribbon supply shaft and the rewind rotation shaft, and a ribbon by the rotation transmission means. An urging force accumulating means for accumulating an urging force for rotating the rewinding rotating shaft in the reverse direction by the rotation of the rewinding rotating shaft transmitted from the supply shaft is provided, and accumulated in the urging force accumulating means by the rotation transmitting means. when to transmit the rotation of the unwinding rotation axis based on the biasing force to the ribbon supply shaft, by configuring so as to increase size of the amount of rotation, the wound ink ribbon in one of the-winding type and back-winding method The ribbon supply shaft that actually rewinds the ink ribbon can be rotated even when the rotation of the rewinding rotary shaft at the time of rewinding is set to approximately half a circle (approximately 180 degrees). Since it is possible to increase size than half (approximately 180 degrees), the wound ink ribbon in one of the-winding type and back-winding method, even when mounted on the ribbon supply shaft, a single ribbon rewinding mechanism It is effective in that a large amount of winding can be ensured.

  In the ribbon supply device of the present invention, the rotation transmission means includes a first gear that is mounted on the ribbon supply shaft and a rewind rotation shaft that is engaged with the first gear. By configuring with the second gear having a large gear ratio with respect to the gear, the gear ratio between the first gear and the second gear is changed even when the rotation of the rewinding rotary shaft during rewinding is determined. Thus, there is an effect that a desired winding amount can be easily set.

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

  FIG. 1 is a schematic side view showing a configuration of a thermal transfer thermal printer in which an embodiment of a ribbon supply apparatus according to the present invention is used, and FIG. 2 is a view of a rewinding mechanism provided on a supply shaft shown in FIG. FIG. 3 is an exploded configuration diagram of the configuration as viewed from the upstream side in the print medium conveyance direction. FIG. 3 illustrates the configuration of the rewind mechanism provided on the supply shaft illustrated in FIG. 1 from the upstream side in the print medium conveyance direction. 4 is a perspective view showing a configuration of a rewinding mechanism provided on the supply shaft shown in FIG. 1, and FIG. 5 is a perspective view showing a configuration of a rotating member and a torque limiter shown in FIG. FIG. 6 and FIG. 7 are explanatory diagrams for explaining the turning operation of the turning member shown in FIG.

  Referring to FIG. 1, the ribbon supply device 10 of the present embodiment is a thermal head 32 that is arranged so that a platen roller 31 and a surface on which a plurality of heating elements are formed in the width direction face the platen roller 31. Is a device that supplies the ink ribbon 1 to the printing unit.

  The thermal transfer type thermal printer 30 includes a printing medium 2 such as a continuous label body in which labels are temporarily attached to a belt-like mount at a predetermined interval or a continuous tag body, etc. It is configured such that printing is performed by transferring the ink from the ink ribbon 1 to the print medium 2 by being nipped and conveyed between the head 32 and the heat generating body of the thermal head 32 selectively generating heat. Further, the printed medium 2 to be printed is separated and discharged at a predetermined position by a cutter device 50 provided at a subsequent stage of the printing unit.

  The print medium 2 is mounted on a print medium supply shaft 33 as a roll paper 3 wound around a cylindrical body such as a paper tube, that is, is rotatably supported. The print medium 2 pulled out by being nipped and transported and pulled out from the print medium supply shaft 33 is guided by the guide roller 34 and guided to the transport path 35, and between the platen roller 31 and the thermal head 32. Supplied. Although not shown in the drawing, a sensor for detecting the print timing, that is, when the print medium 2 is a continuous label, is a sensor that detects the label pitch, and the print medium 2 is a continuous tag. In the case of a body, a sensor or the like for detecting the center hole is arranged. A reference numeral 36 shown in FIG. 1 is a roll paper guide plate for guiding the roll paper 3 mounted on the print medium supply shaft 33.

  The ribbon supply device 10 includes a ribbon supply shaft 11 that is mounted in a state where an unused ink ribbon 1 is wound in a roll shape, and a ribbon take-up shaft 12 that is rotationally driven in conjunction with a platen roller 31. The ink ribbon 1 is stretched between the ribbon supply shaft 11 and the ribbon take-up shaft 12 so as to pass through the printing unit. The unused ink ribbon 1 mounted on the ribbon supply shaft 11 is pulled out from the ribbon supply shaft 11 by winding the ink ribbon 1 after use, that is, after transfer, by the ribbon take-up shaft 12, so that the printing unit, The print medium 2 is supplied between the platen roller 31 and the thermal head 32. 1 is a guide roller for guiding the unused ink ribbon 1 drawn from the ribbon supply shaft 11 to the printing unit, and reference numerals 38 and 39 shown in FIG. 1 are ink ribbons after transfer. 1 is a guide roller for guiding 1 to the ribbon take-up 12.

  In the thermal transfer type thermal printer 30, the printing medium 2 is separated at a predetermined position by the cutter device 50, and when the separated printed medium 2 is discharged, the printing medium 2 is conveyed in the reverse direction by the reverse rotation operation of the platen roller 31. Further, back feeding is performed so that the unprinted leading end portion of the printing medium 2 is returned to the printing position of the thermal head 32, and the ink ribbon 1 drawn out at the time of back feeding is supplied to the ribbon supply shaft 11. Is provided with a ribbon rewinding mechanism for rewinding the drawn ink ribbon 1 by a predetermined length.

  2 and 3, the ribbon supply shaft 11 is mounted on the ribbon supply rotation shaft 13 and the ribbon supply rotation shaft 13 rotatably supported by the side plate 40 and the support frame 15, and is unused. The ink ribbon 1 includes a boss portion 14 that is mounted in a rolled state, and a ribbon rewinding mechanism is provided between the side plate 40 and the support frame 15. The ribbon supply rotating shaft 13 itself may be used as the ribbon supply shaft 11.

  FIG. 2 shows a component configuration of a ribbon unwinding mechanism provided on the ribbon supply shaft 11. The ribbon unwinding mechanism is mounted on the ribbon supply rotating shaft 13 and is supplied to the ribbon by referring to FIG. A small gear 16 that rotates together with the rotary shaft 13, a rewind rotary shaft 17 that is arranged in parallel with the ribbon supply rotary shaft 13 and is rotatably supported between the side plate 40 and the support frame 15 attached to the side plate 40. The rotating member 18 loosely mounted on the rewinding rotating shaft 17, the large gear 19 that is mounted on the rewinding rotating shaft 17 and rotates together with the rewinding rotating shaft 17, and the rotating member 18 from the rewinding rotating shaft 17. A torque limiter 20 that controls rotation transmission to the torque limiter, a torsion coil spring 21 that is loosely mounted on the torque limiter 20, and a stopper pin 22 that is fixed to the side plate 40 and restricts the rotation of the rotation member 18. It is fixed to the side plate 40, an end portion of the torsion coil spring 21 and a locking pin 23 to be engaged.

  The support frame 15 has a support surface that supports the ribbon supply rotary shaft 13 and the rewind rotary shaft 17 so as to be rotatable, and is opposed to the side plate 40 at a predetermined interval, and is attached to the side plate 40 or a chassis (not shown). Yes. Further, the stopper pin 22 and the locking pin 23 may be fixed to the support frame 15.

  Referring to FIGS. 3 and 4, the small gear 16 mounted on the ribbon supply rotating shaft 13 and the large gear 19 mounted on the rewinding rotating shaft 17 are assembled so as to mesh with each other. The large gear 19 functions as a rotation transmission means for transmitting the rotation between the ribbon supply shaft 11 and the rewinding rotation shaft 17. Further, the gear ratio between the large gear 19 and the small gear 16 is set so that the large gear 19 is larger. Therefore, when transmitting the rotation from the ribbon supply rotating shaft 13 to the rewinding rotating shaft 17, The rotation amount decreases, and the rotation amount increases when the rotation is transmitted from the rewinding rotation shaft 17 to the ribbon supply rotation shaft 13. In FIG. 4, a state where the support frame 15 is removed is shown.

  Referring to FIG. 5, the rotating member 18 includes a cylindrical cylindrical portion 181 and a donut-shaped disc portion 182 that are integrally formed. The cylindrical portion 181 is the side plate 40, and the disc portion 182 is the torque limiter. 20 is loosely mounted on the rewinding rotary shaft 17 so as to face each other. A contact plate 183 that is in contact with the stopper pin 22 by the rotation of the rotation member 18 is formed on the outer peripheral surface of the cylindrical portion 181. In addition, a mounting hole 184 is formed on the surface of the disk portion 182 facing the torque limiter 20, and extends to the peripheral surface of the torque limiter 20 to engage with the end of the torsion coil spring 21. The engaging pin 185 is provided at a location rotated 180 degrees around the axis from the location where the contact plate 183 is formed.

  Referring to FIG. 5, the torque limiter 20 is attached to the inner ring portion 201 that is mounted on the rewinding rotary shaft 17 and rotates together with the rewinding rotary shaft 17, and the opposing surface that faces the rotary member 18. The outer ring portion 203 is formed with a projection 202 to be fitted into the fitted hole 184 formed in the disc portion 182, and the projection 202 is fitted into the fitted hole 184. The outer ring portion 203 of the torque limiter 20 and the rotation member 18 are integrated in the rotation direction.

  As shown in FIG. 4 and FIG. 6A, the torsion coil spring 21 has both ends projecting in substantially the same direction, the coil portion is loosely mounted on the torque limiter 20, and both ends are the circles of the rotating member 18. The engagement pin 185 provided on the plate portion 182 and the locking pin 23 fixed to the side plate 40 are assembled so as to be sandwiched therebetween. FIG. 6 shows a state in which the rotating member 18 is viewed from the axial direction on the torque limiter 20 side.

  In this assembled state, as shown in FIG. 7A, the contact plate 183 formed on the cylindrical portion 181 of the rotation member 18 and the contact plate 183 come into contact with the contact plate 183. The stopper pin 22 that restricts the rotation is disposed on the opposite side across the rewinding rotation shaft 17. Therefore, the rotation of the rotation member 18 is as shown in FIGS. 7 (b) and 7 (c). Regardless of the clockwise direction or the counterclockwise direction, the contact plate 183 contacts the stopper pin 22 to be regulated to about 180 degrees. FIG. 7 shows a state in which the rotating member 18 is viewed from the axial direction on the side plate 40 side.

  The rotating member 18, the torsion coil spring 21, and the locking pin 23 function as an urging force accumulating unit that accumulates an urging force that rotates the rewinding rotation shaft 17 in the reverse direction by the rotation of the rewinding rotation shaft 17. That is, in FIG. 6B, as shown in FIG. 7B, the rotating member 18 is rotated in the direction indicated by the arrow A ′ until the contact plate 183 contacts the stopper pin 22. In the state in which one end of the torsion coil spring 21 is engaged with the engagement pin 23 fixed to the side plate 40, the other end of the torsion coil spring 21 is the engagement pin of the rotating member 18. By being twisted by 185, the urging force that rotates the rotating member 18 in the direction indicated by the arrow B ′, that is, the direction opposite to the rotated direction is accumulated in the torsion coil spring 21. 6C, the rotating member 18 is rotated in the direction indicated by the arrow B ′ until the contact plate 183 contacts the stopper pin 22, as shown in FIG. 7C. In the state in which one end of the torsion coil spring 21 is engaged with the engagement pin 23 fixed to the side plate 40, the other end of the torsion coil spring 21 is the engagement pin of the rotating member 18. By being twisted by 185, the urging force that rotates the rotating member 18 in the direction indicated by the arrow A ′, that is, the direction opposite to the rotated direction is accumulated in the torsion coil spring 21.

Next, the ribbon rewinding operation of the present embodiment will be described in detail with reference to FIG.
FIG. 8 is a perspective view for explaining a rewinding operation by a rewinding mechanism provided on the supply shaft shown in FIG.

  There are two methods for winding the ink ribbon 1: a front winding method in which the thermal transfer surface is exposed on the surface of the roll, and a reverse winding method in which the thermal transfer surface is located on the inner side of the roll. The ink ribbon 1 wound by either the front winding method or the back winding method can be used.

First, a ribbon rewinding operation when the ink ribbon 1 wound by the front winding method is mounted on the ribbon supply shaft 11 will be described.
When the ink ribbon 1 wound by the front winding method is mounted on the ribbon supply shaft 11 and the printing operation is started, the ribbon take-up shaft 12 rotates in conjunction with the platen roller 31 to the ribbon take-up shaft 12. The winding of the ink ribbon 1 is started. As a result, when the ink ribbon 1 unwound from the ribbon supply shaft 11 is pulled, a force for pulling out the ink ribbon 1 from the ribbon supply shaft 11 acts, and the ink ribbon 1 is pulled out from the ribbon supply shaft 11 to supply the ribbon. The shaft 11, that is, the boss portion 14 (ribbon supply rotating shaft 13) rotates in the direction indicated by the arrow A in FIG.

  The rotation of the ribbon supply rotary shaft 13 is transmitted to the rewind rotary shaft 17 via the meshed small gear 16 and large gear 19, and the rewind rotary shaft 17 rotates in the direction indicated by arrow A 'in FIG. As the rewinding rotary shaft 17 rotates, the torque limiter 20 and the rotating member 18 are moved in the direction of the arrow A until the contact plate 183 of the rotating member 18 contacts the stopper pin 22 as shown in FIG. Rotate approximately 180 degrees together with the rewinding rotary shaft 17 in the direction indicated by ', and as shown in FIG. 6 (b) by the rotation of the rotating member 18, the direction opposite to the rotated direction, that is, the arrow B' The biasing force that rotates the rotating member 18 in the direction shown is accumulated in the torsion coil spring 21. In addition, although the torque acts between the inner ring part 201 and the outer ring part 203 in the torque limiter 20 by the biasing force of the torsion coil spring 21, the set torque of the torque limiter 20 is the biasing force of the torsion coil spring 21. The inner ring portion 201 and the outer ring portion 203 rotate together until the contact plate 183 of the rotating member 18 contacts the stopper pin 22.

  Next, as shown in FIG. 7B, when the abutting plate 183 of the rotating member 18 abuts against the stopper pin 22, a torque greater than the set torque is set between the inner ring portion 201 and the outer ring portion 203 in the torque limiter 20. Torque acts, and the inner ring part 201 and the outer ring part 203 rotate relative to each other while maintaining a constant torque, that is, the inner ring part 201 rotates while maintaining a constant torque while the outer ring part 203 is stopped. As a result, the rewind rotary shaft 17 and the ribbon supply rotary shaft 13 are rotated in the direction indicated by the arrow A ′ in FIG. 4 while maintaining a constant torque, and the ink ribbon 1 is pulled out from the ribbon supply shaft 11 with a constant torque. Will be.

  Next, when the printing operation is completed and the back feed for conveying the print medium 2 in the reverse direction is performed, the rotation of the ribbon take-up shaft 12 is stopped. Since the rotation of the ribbon take-up shaft 12 is stopped and the force for pulling out the ink ribbon 1 from the ribbon supply shaft 11 does not act, the rotating member 18 is caused to move by the torque limiter 20 and the biasing force accumulated in the torsion coil spring 21. Together with the rewinding rotary shaft 17, it is rotated by approximately 180 degrees in the direction indicated by the arrow B 'in FIG. The rotation of the rewinding rotary shaft 17 is transmitted to the ribbon supply rotary shaft 13 through the meshing large gear 19 and small gear 16, and the ribbon supply rotary shaft 13 (boss portion 14), that is, the ribbon supply shaft 11 is shown in FIG. The ink ribbon 1 rotated and rotated in the direction indicated by the arrow B in (a) is rewound. Here, since the gear ratio between the large gear 19 and the small gear 16 is set so that the large gear 19 is larger, the rotation amount of the ribbon supply rotation shaft 13 is the rotation amount of the rewind rotation shaft 17. More than. For example, when the gear ratio between the large gear 19 and the small gear 16 is set to 2: 1, the rotation amount of the rewinding rotation shaft 17 is approximately 180 degrees, whereas the ribbon supply rotation shaft 13 The amount of rotation is approximately 360 degrees. By setting the gear ratio between the large gear 19 and the small gear 16 in this way, the amount of rewinding of the ink ribbon 1 that needs to be rewound onto the ribbon supply shaft 11 at the time of back feed is achieved. Even large cases can be accommodated.

Next, a ribbon rewinding operation when the ink ribbon 1 wound by the reverse winding method is mounted on the ribbon supply shaft 11 will be described.
When the ink ribbon 1 wound by the reverse winding method is mounted on the ribbon supply shaft 11 and the printing operation is started, the ribbon take-up shaft 12 rotates in conjunction with the platen roller 31 to the ribbon take-up shaft 12. The winding of the ink ribbon 1 is started. As a result, when the ink ribbon 1 unwound from the ribbon supply shaft 11 is pulled, a force for pulling out the ink ribbon 1 from the ribbon supply shaft 11 acts, and the ink ribbon 1 is pulled out from the ribbon supply shaft 11 to supply the ribbon. The shaft 11, that is, the boss portion 14 (ribbon supply rotating shaft 13) rotates in the direction indicated by the arrow B in FIG.

  The rotation of the ribbon supply rotary shaft 13 is transmitted to the rewind rotary shaft 17 through the meshed small gear 16 and large gear 19, and the rewind rotary shaft 17 rotates in the direction indicated by the arrow B 'in FIG. As the rewinding rotary shaft 17 rotates, the torque limiter 20 and the rotating member 18 are moved in the direction of the arrow B until the contact plate 183 of the rotating member 18 contacts the stopper pin 22 as shown in FIG. Rotate approximately 180 degrees together with the rewinding rotary shaft 17 in the direction indicated by ', and as shown in FIG. 6C by the rotation of the rotating member 18, the direction opposite to the rotated direction, that is, the arrow A' The biasing force that rotates the rotating member 18 in the direction shown is accumulated in the torsion coil spring 21. In addition, although the torque acts between the inner ring part 201 and the outer ring part 203 in the torque limiter 20 by the biasing force of the torsion coil spring 21, the set torque of the torque limiter 20 is the biasing force of the torsion coil spring 21. The inner ring portion 201 and the outer ring portion 203 rotate together until the contact plate 183 of the rotating member 18 contacts the stopper pin 22.

  Next, as shown in FIG. 7C, when the contact plate 183 of the rotating member 18 contacts the stopper pin 22, a torque greater than the set torque is set between the inner ring portion 201 and the outer ring portion 203 in the torque limiter 20. Torque acts, and the inner ring part 201 and the outer ring part 203 rotate relative to each other while maintaining a constant torque, that is, the inner ring part 201 rotates while maintaining a constant torque while the outer ring part 203 is stopped. Accordingly, the rewinding rotary shaft 17 and the ribbon supply rotary shaft 13 are rotated in the direction indicated by the arrow B ′ in FIG. 4 while maintaining a constant torque, and the ink ribbon 1 is pulled out from the ribbon supply shaft 11 with a constant torque. Will be.

  Next, when the printing operation is finished and the back feed for conveying the printing medium 2 in the reverse direction is performed, the rotation of the ribbon take-up shaft 12 is stopped. Since the rotation of the ribbon take-up shaft 12 is stopped and the force for pulling out the ink ribbon 1 from the ribbon supply shaft 11 does not act, the rotating member 18 is caused to move by the torque limiter 20 and the biasing force accumulated in the torsion coil spring 21. Together with the rewinding rotary shaft 17, it is rotated by approximately 180 degrees in the direction indicated by the arrow A 'in FIG. The rotation of the rewinding rotary shaft 17 is transmitted to the ribbon supply rotary shaft 13 through the meshing large gear 19 and small gear 16, and the ribbon supply rotary shaft 13 (boss portion 14), that is, the ribbon supply shaft 11 is shown in FIG. The ink ribbon 1 rotated and rotated in the direction indicated by the arrow A in (b) is rewound. Here, since the gear ratio between the large gear 19 and the small gear 16 is set so that the large gear 19 is larger, the rotation amount of the ribbon supply rotation shaft 13 is the rotation amount of the rewind rotation shaft 17. Will be more than. For example, when the gear ratio between the large gear 19 and the small gear 16 is set to 2: 1, the rotation amount of the rewinding rotation shaft 17 is approximately 180 degrees, whereas the ribbon supply rotation shaft 13 The amount of rotation is approximately 360 degrees. By setting the gear ratio between the large gear 19 and the small gear 16 in this way, the amount of rewinding of the ink ribbon 1 that needs to be rewound onto the ribbon supply shaft 11 at the time of back feed is achieved. Even large cases can be accommodated.

  As described above, according to the present embodiment, the rewind rotation shaft 17 arranged in parallel with the ribbon supply shaft 11 and the rotation between the ribbon supply shaft 11 and the rewind rotation shaft 17 are transmitted. The rotation transmitting means composed of the small gear 16 and the large gear 19 and the urging force for rotating the rewinding rotating shaft 17 in the reverse direction by the rotation of the rewinding rotating shaft 17 transmitted from the ribbon supply shaft 11 by the rotation transmitting means. A rotation member 18 that accumulates in the torsion coil spring 21, and the rotation transmission means transmits the rotation of the rewinding rotation shaft 17 based on the biasing force accumulated in the torsion coil spring 21 to the ribbon supply shaft 11. By configuring so as to increase the amount of rotation, rewinding can be performed so that the ink ribbon 1 wound by either the front winding method or the back winding method can be handled. Even when the rotation of the rewinding rotation shaft 17 is set to approximately half a circle (approximately 180 degrees), the rotation of the ribbon supply shaft 11 that actually rewinds the ink ribbon 1 can be increased more than approximately half a circle (approximately 180 degrees). Therefore, even when the ink ribbon 1 wound by either the front winding method or the back winding method is mounted on the ribbon supply shaft 11, a large winding amount is ensured by using a single ribbon rewinding mechanism. There is an effect that can be.

  Furthermore, according to the present embodiment, the small gear 16 that is mounted on the ribbon supply shaft 11 and the rewinding rotary shaft 17 that is mounted on the small gear 16 and meshed with the small gear 16 have a large gear ratio. By constituting the rotation transmission means with the large gear 19, even when the rotation of the rewinding rotary shaft 17 at the time of rewinding is determined, the gear ratio between the small gear 16 and the large gear 19 can be changed easily. There is an effect that a desired winding amount can be set.

  Note that the present invention is not limited to the above-described embodiments, and it is obvious that the embodiments can be appropriately changed within the scope of the technical idea of the present invention. In addition, the number, position, shape, and the like of the constituent members are not limited to the above-described embodiment, and can be set to a number, position, shape, and the like that are suitable for implementing the present invention. In each figure, the same numerals are given to the same component.

1 is a schematic side view showing a configuration of a thermal transfer thermal printer in which an embodiment of a ribbon supply device according to the present invention is used. FIG. 2 is an exploded configuration diagram of a configuration of a rewinding mechanism provided on a supply shaft shown in FIG. 1 as viewed from the upstream side in the print medium conveyance direction. FIG. 2 is a configuration diagram of a configuration of a rewinding mechanism provided on a supply shaft shown in FIG. 1 as viewed from the upstream side in the print medium conveyance direction. It is a perspective view which shows the structure of the rewinding mechanism provided in the supply shaft shown in FIG. It is a perspective view which shows the structure of the rotation member shown in FIG. 3, and a torque limiter. It is explanatory drawing for demonstrating rotation operation | movement of the rotation member shown in FIG. It is explanatory drawing for demonstrating rotation operation | movement of the rotation member shown in FIG. It is a perspective view for demonstrating the rewinding operation | movement by the rewinding mechanism provided in the supply shaft shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ink ribbon 2 Medium to be printed 3 Roll paper 10 Ribbon supply apparatus 11 Ribbon supply shaft 12 Ribbon take-up shaft 13 Ribbon supply rotation shaft 14 Boss part 15 Support frame 16 Small gear 17 Rewind rotation shaft 18 Rotating member 19 Large gear 20 Torque limiter 21 Torsion coil spring 22 Stopper pin 23 Locking pin 31 Platen roller 32 Thermal head 30 Thermal transfer thermal printer 33 Print medium supply shaft 34 Guide roller 35 Transport path 36 Roll paper guide plate 37, 38, 39 Guide roller 40 Side plate DESCRIPTION OF SYMBOLS 50 Cutter apparatus 181 Cylindrical part 182 Disk part 183 Contact plate 184 Fit hole 185 Engagement pin 201 Inner ring part 202 Projection part 203 Outer ring part

Claims (2)

A ribbon supply shaft that is mounted in a state where an unused ink ribbon is wound in a roll shape, and a ribbon take-up shaft that is driven to rotate in conjunction with a platen roller. A ribbon supply device for pulling out the unused ink ribbon from the ribbon supply shaft by winding up the ink ribbon;
A rewinding rotating shaft disposed parallel to the ribbon supply shaft;
A small gear provided on the ribbon supply shaft, and a large gear provided on the rewinding rotation shaft,
Transmitting the rotation between the ribbon supply shaft and the rewinding rotation shaft by the small gear and the large gear,
Urging force accumulation means for accumulating an urging force for rotating the rewinding rotary shaft in the reverse direction by the rotation of the rewinding rotary shaft transmitted from the ribbon supply shaft by the small gear and the large gear;
The biasing power accumulation means
A torque limiter for controlling rotation transmission to the rotating member loosely mounted on the rewinding rotating shaft;
A stopper pin that regulates approximately 180 degrees in any direction of the rotating member;
A coil spring that accumulates an urging force by the rotation of the rotating member;
A ribbon supply device, wherein the rotation of the rewinding rotary shaft based on the urging force accumulated in the coil spring is transmitted to the ribbon supply shaft with an increased amount of rotation. A small gear that is mounted on the ribbon supply shaft, and a large gear that is mounted on the rewinding rotary shaft and meshed with the small gear.
2. The ribbon supply device according to claim 1, wherein a ratio of the small gear to the large gear is set to 1: 2.

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