JPH05286218A - Ink ribbon driving device in heat transfer printere - Google Patents

Abstract

PURPOSE:To constitute the title device so that wind-up of an ink ribbon can be performed stably at the time of bidirectional running of a carriage, by a method wherein a cam member controlling a turning position of a support lever is provided so that either one transmission gear gears selectively with rack. CONSTITUTION:A thermal head 4 is pressure-contacted with a platen 1 through an ink ribbon and paper. Then the first wind-up force transmission gear 15 gears with a rack 5 by a method wherein support levers 13, 33 each wherein cam followers 21, 41 are fitted respectively into cam grooves by driving of a disc cam 6 under this condition are turned. On this occasion, when a carriage 2 runs in a rightward direction as per an arrow, the first wind-up force transmission gear 15 gearing with the rack 5 is tuned clockwise by running of the carriage 2. Then a wind-up gear 12 is turned counter-clockwise along with wind-up spool 11. Consequently, the ink ribbon provided for printing can be wound round a wind-up reel within a ribbon cassette.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer printer in which ink of an ink ribbon is partially melted by heat generated by a thermal head to perform printing, and in particular, the ink ribbon is wound and wound even when not printing. And / or an ink ribbon drive device for rewinding.

[0002]

2. Description of the Related Art Generally, the thermal transfer printer described above winds a thermal head which can be brought into contact with and separated from a platen, and an ink ribbon which is sandwiched between the thermal head and the platen together with a paper, on a supply reel and a take-up reel. A ribbon cassette that can be rotated and stored is mounted on the carriage, and while the thermal head is in pressure contact with the platen via the ink ribbon and the paper, the heating elements of the thermal head correspond to the print information while the carriage runs along the platen. Then, heat is selectively generated, and ink is melted from the ink ribbon at a portion facing the heat-generating element that has generated heat, and the ink is transferred to the paper to perform printing.

In such a thermal transfer printer, when the thermal head is pressed against the platen via the ink ribbon and the paper, the ink ribbon pressed against the paper by the thermal head does not have a relative speed with the paper. As a result, the ribbon cassette is unwound from the supply reel of the ribbon cassette as the carriage travels, and is wound onto the take-up reel by the rotation of the take-up reel.

Therefore, conventionally, a rack is arranged along the traveling direction of the carriage, and a pinion that meshes with the rack and drives the winding shaft to rotate in the winding direction is arranged on the carriage. The take-up reel is rotationally driven in the take-up direction by a pinion that rotates as the vehicle runs, and the unwound ink ribbon is taken up on the take-up reel.

By the way, in a color ink ribbon in which a plurality of colors of ink are repeatedly adhered in order in the running direction, ink of a predetermined color is provided for printing after the end of printing and before the start of the next printing. Ink ribbon of a certain length must be wound up.

Further, a thermal transfer printer has been developed which uses a multi-time ink ribbon that can be used a plurality of times (multi-time ribbon) to perform unattended printing. In this thermal transfer printer, all the multi-time ribbons are wound. This multi-time ribbon must be automatically rewound once it is wound onto the shaft.

By the way, there is a conventional ink ribbon drive device in which a motor is mounted on a carriage and the ink ribbon is automatically wound by the motor.

[0008]

However, the above-mentioned conventional one has to be mounted in the space in the carriage and must be made small in size. As a result, the torque of the motor becomes small and the ink ribbon becomes small. Took a long time to wind up. Further, for this reason, the motor has to be driven for a long time, which may cause heat generation from the motor. Further, since the ink ribbon can only be wound up, it cannot be applied to a thermal transfer printer for unattended operation in which the ink ribbon must be automatically rewound.

In view of the above points, an object of the present invention is to provide an ink ribbon driving device in a thermal transfer printer which can stably wind an ink ribbon when the carriage is running in both directions.

It is another object of the present invention to provide an ink ribbon drive device in a thermal transfer printer which can stably rewind the ink ribbon when the carriage is running in both directions.

It is another object of the present invention to provide an ink ribbon drive device in a thermal transfer printer which can selectively and stably wind or rewind the ink ribbon when the carriage is running in both directions. And

[0012]

In order to achieve the above-mentioned object, an ink ribbon drive device in a thermal transfer printer according to claim 1 of the present invention is a thermal head which can be brought into contact with and separated from a platen, and between the thermal head and the platen. In a thermal transfer printer in which a carriage is mounted with a ribbon cassette that stores an ink ribbon that is nipped together with a paper by being wound around a supply shaft and a take-up shaft, and a rack that is arranged in the traveling direction of the carriage, The take-up gear that rotates the take-up shaft and a pair of transmission gears that can selectively mesh with the rack when the carriage travels in one direction are provided. A transmission means for transmitting to the gear, a support lever for supporting the transmission means, and any one of the transmission gears are selectively meshed with the rack. It is characterized in that a cam member which controls the rotational position of the support lever so that.

According to another aspect of the present invention, there is provided an ink ribbon driving device for a thermal transfer printer in which a thermal head which can be brought into contact with and separated from a platen, and an ink ribbon which is sandwiched between the thermal head and the platen together with a sheet are wound around a supply shaft. A thermal transfer printer comprising a carriage and a ribbon cassette wound around a shaft and housed in the carriage, a rack arranged in a traveling direction of the carriage, a winding gear for rotationally driving the winding shaft, and A winding force transmission gear that selectively meshes with the rack and transmits the driving force of the rack to the winding gear, a supply gear that rotates and drives the supply shaft, and the rack when the carriage travels in one direction. A transmission means having a pair of transmission gears capable of selectively meshing and transmitting the rotation of each transmission gear to the supply gear; A support lever for lifting, is characterized in that any one of the transmission gear is provided with a cam member which controls the rotational position of the support lever so as to be able to mesh with the selectively the rack.

Further, in the ink ribbon driving device in the thermal transfer printer of the third aspect, the thermal head which can be brought into contact with and separated from the platen, and the ink ribbon which is sandwiched between the thermal head and the platen together with the paper are wound around the supply shaft. A thermal transfer printer comprising a carriage and a ribbon cassette wound around a shaft and housed in the carriage, a rack arranged in a traveling direction of the carriage, a winding gear for rotationally driving the winding shaft, and It has a rewinding gear that drives the supply shaft to rotate in the rewinding direction of the ink ribbon, and a pair of rewinding force transmission gears that can selectively mesh with the rack when the carriage travels in either direction. A first transmission hand that transmits the rotation of any one of the winding force transmission gears to the winding gear to rotate the winding shaft in the winding direction. And a pair of rewinding force transmission gears that can selectively mesh with the rack when the carriage travels in any one direction, the first support lever supporting the first transmission means. Any of a second transmission means for transmitting the rotation of the rewinding force transmission gear to the rewinding gear to rotate the winding shaft in the rewinding direction, and a second support lever for supporting the second transmission means. A cam member for controlling the rotational positions of the support levers is provided so that one of the transmission gears can be selectively meshed with the rack.

[0015]

According to the ink ribbon drive device in the thermal transfer printer of the first aspect, the carriage travels among the transmission means supported by the support lever by driving the cam member while the thermal head is in the head-up state. The take-up shaft can rotate in the ink ribbon take-up direction according to the direction, and the support lever is turned so that one of the transmission gears meshes with the rack and the carriage travels to take the ink ribbon take-up shaft. It can be wound stably.
Further, even when the carriage travels to the end of its travel range, when it is still necessary to continue winding the ink ribbon, the cam member is driven again to rotate the support lever,
By releasing the meshing of the transmission gear that was meshed with the rack up to that point with the rack, meshing the other transmission gear with the rack, and running the carriage in the reverse direction to continue winding the ink ribbon, The ink ribbon can be wound up to the position.

Further, according to the ink ribbon drive device in the thermal transfer printer of the second aspect, the cam member is driven while the thermal head is head-up,
Of the transmission means supported by the support lever, the support lever is rotated so that one of the transmission gears that can rotate the supply shaft in the ink ribbon rewinding direction corresponding to the traveling direction of the carriage meshes with the rack. By running the carriage, the ink ribbon can be stably wound around the supply shaft. Further, even when the carriage has traveled to the end of its travel range, if the ink ribbon must still be wound up, the cam member is driven again to rotate the support lever, and the support lever has been engaged until then. Rewind the ink ribbon to a predetermined position by releasing the meshing of the transmission gear with the rack, meshing the other transmission gear with the rack, and running the carriage in the opposite direction to continue the rewinding of the ink ribbon. be able to.

Further, according to the ink ribbon driving device in the thermal transfer printer of the third aspect, the ink ribbon can be wound or unwound as necessary.

That is, for winding up the ink ribbon, the cam member is driven and the first supporting lever is supported by the first supporting lever while the thermal head is in the head-up state.
By rotating the support lever so that one of the transmission gears, which can rotate the take-up shaft in the ink ribbon take-up direction corresponding to the traveling direction of the carriage, meshes with the rack, the carriage is made to travel. The ink ribbon can be stably wound around the winding shaft. On the other hand, in the state where the thermal head is headed up, the cam member is driven to wind the ink ribbon around the supply shaft corresponding to the traveling direction of the carriage of the second transmission means supported by the second support lever. By rotating the support lever so that one of the transmission gears that can rotate in the returning direction meshes with the rack and causing the carriage to travel, the ink ribbon can be stably wound around the supply shaft.

[0019]

The present invention will be described below with reference to the embodiments shown in the drawings.

1 to 5 show an embodiment of the present invention. This embodiment corresponds to claim 3 and is capable of both winding and rewinding.

1 to 5, a support arm 3 is rotatably supported by a front portion of a carriage 2 which can run in both left and right directions along a platen 1 formed on a printer body (not shown). A thermal head 4 is attached to the support arm 3 so as to be brought into contact with and separated from the platen 1 as the support arm 3 rotates.
The support arm 4 is rotated by a driving means such as a motor (not shown). A rack 5 extending in the traveling direction of the carriage 2 is arranged in the printer body.

On the carriage 2, a take-up spool 11 and a supply spool 31 are rotatably projected at right and left intervals. The take-up spool 11 and the supply spool 31 are the same as the carriage 2 described above.
The reels (not shown) of the ribbon cassette (not shown) are fitted to the winding reel (winding shaft) and the supply reel (supplying shaft) to rotate each reel.

On the outer circumference of the take-up spool 11, a take-up gear 12 is arranged so as to rotate integrally with the take-up spool 11.
Further, a rewinding gear 32 is fitted on the outer periphery of the supply spool 31 so as to rotate integrally with the supply spool 31.

The carriage 2 has a first support lever 13
Is rotatably supported by the support shaft 14. The first
The support lever 13 rotatably supports a first winding force transmission gear 15 and a second winding force transmission gear 15 which can be selectively meshed with the rack 5 depending on the rotational position of the first support lever 13. Has been done. It should be noted that these two winding force transmission gears 15 and 16 can also take positions where neither of them meshes with the rack 5 due to the rotational position of the first support lever 13.

A first idler 17, a second idler 18, and a third idler 19 are rotatably supported on the first support lever 13, respectively. Of these, the first idler 17 meshes with the first winding force transmission gear 15. The second idler 18 and a third idler 19 having a larger diameter than that are supported by the support shaft 14 so as to rotate integrally therewith, and the second idler 18 is the second winding force transmission gear. 16 and the first idler 1
7, and the third idler 19 meshes with the winding gear 12.

Therefore, the two winding force transmission gears 1 are
By rotating the winding gears 12 and 16 in opposite directions, the winding gear 12 is rotated counterclockwise to wind up the ink ribbon. That is, the first winding force transmission gear 15 rotates clockwise to cause the winding gear 1 to rotate.
2 is rotated counterclockwise, the second winding force transmission gear 16 is rotated counterclockwise to rotate the winding gear 12 counterclockwise.

Therefore, the first winding force transmission gear 15
Is for rotating the winding gear 12 in the winding direction when the carriage meshes with the rack 5 when the carriage travels in the printing direction from left to right in each figure, while the second winding force transmission is performed. The gear 16 rotates the winding gear 12 in the winding direction when the gear 16 meshes with the rack 5 when the carriage travels in the carriage return direction from right to left in each drawing.

The two winding force transmission gears 15 and 16 are
The idlers 17, 18, 19 and the like constitute the first transmission means 20.

A second support lever 33 is rotatably supported on the carriage 2 by a support shaft 34. The second support lever 33 has a first position that can be selectively meshed with the rack 5 depending on the rotation position of the second support lever 33.
Rewinding force transmission gear 35 and second unwinding force transmission gear 36
Are rotatably supported. The two rewinding force transmission gears 35 and 36 can be set in positions where none of them meshes with the rack 5 depending on the rotational position of the second support lever 33.

A first idler 37, a second idler 38 and a third idler 39 are rotatably supported on the second support lever 33, respectively. Of these, the first idler 37 meshes with the first rewinding force transmission gear 35. Further, the second idler 38 and the third idler 39 having a larger diameter than that are supported by the support shaft 34 so as to be integrally rotatable, and the second idler 38 is the second rewinding force transmission gear. 36 and the first idler 3
7, and the third idler 39 meshes with the rewinding gear 32.

Therefore, the two rewinding force transmitting gears 3
5, 5 and 36 rotate in opposite directions to rotate the rewinding gear 32 in the clockwise direction to rewind the ink ribbon. That is, the first winding force transmission gear 1
5 is rotated in the counterclockwise direction to rotate the rewinding gear 3
While the second rewinding force transmitting gear 36 rotates clockwise while the second rewinding gear 32 rotates clockwise, the rewinding gear 32 rotates clockwise.

Therefore, the second unwinding force transmitting gear 36
Is for rotating the rewinding gear 32 in the rewinding direction when meshing with the rack 5 when the carriage travels in the printing direction from left to right in each figure, while the first rewinding force transmission is performed. The gear 35 rotates the rewinding gear 32 in the rewinding direction when meshed with the rack 5 when the carriage travels in the carriage return direction from right to left in each drawing.

The both rewinding force transmission gears 35 and 36 are
In addition, each idler 37, 38, 39, etc. constitutes the second transmission means 40. Further, the first transmission means 20 supported by the first support lever 13 and the second support lever 33.
The respective gears are arranged so as to be line-symmetrical to the second transmission means 40 supported by.

A rotatable cam follower 21 is supported at the tip of the first support lever 13, and a rotatable cam follower 41 is similarly supported at the tip of the second support lever 33. ing. On the other hand, on the carriage 2 between the winding gear 12 and the rewinding gear 32, a disk cam 6 as an example of a cam member is supported so as to be rotatable by a driving means such as a motor (not shown). .. The disc cam 6 has two cam followers 2
Two cam grooves (not shown) into which 1 and 41 are individually fitted are formed, and the disc cam 6 regulates the positions of the cam followers 21 and 41 by its rotating position, and each of the support levers 13 is formed. , 33 to the transmission gears 15, 16,
The position where only one of the gears 35 and 36 selectively engages with the rack 5 and the transmission gears 15, 16, 35,
All of the positions 36 are set so as not to mesh with the rack 5.

Next, the operation of this embodiment having the above-mentioned structure will be described.

FIG. 1 shows a printing state. In this state, the thermal head 4 is in pressure contact with the platen 1 via an ink ribbon and paper (not shown). Further, in this state, the driving of the disc cam 6 causes the support levers 13 and 33 in which the cam followers 21 and 41 are fitted in the cam grooves (not shown) to rotate, whereby the first winding force transmission gear 15 meshes with the rack 5.

In this state, the carriage 5 is moved to the position shown in FIG.
When you move to the right as indicated by the arrow in the
The first take-up force transmission gear 15 meshing with is rotated clockwise by the traveling of the carriage 5 to rotate the take-up gear 12 together with the take-up spool 11 in the counter-clockwise direction. The ink ribbon used for printing can be wound around the take-up reel.

FIG. 2 shows an ink of a certain length such that ink of a predetermined color is provided for printing after the end of printing and before the start of the next printing, as in the case of color printing using a color ribbon. This shows the operation of winding the ink ribbon in the non-printing state, which is applied when the ribbon has to be fed idly. In this state, the thermal head 4 is separated from the platen 1. Further, in this state, the first winding force transmission gear 15 is meshed with the rack 5 as in the printing state of FIG.

In this state, the carriage 5 is moved to the position shown in FIG.
When you move to the right as indicated by the arrow in the
The first take-up force transmission gear 15 meshing with is rotated clockwise by the traveling of the carriage 5 to rotate the take-up gear 12 together with the take-up spool 11 in the counter-clockwise direction. The ink ribbon can be wound around the take-up reel.

By the way, in the above-described color ribbon idling, a photo sensor or the like is used to detect that the ink of a specific color of the ink ribbon is located at a predetermined position. However, the ink of a specific color of the ink ribbon is detected. When reaches the predetermined position, the disc cam 6 is driven to release the first winding force transmission gear 15 from the mesh with the rack 5.
On the other hand, if the ink of the specific color of the ink ribbon has not reached the predetermined position even when the carriage 5 is moved to the final position in the right direction, the disk cam 6 is driven to move the ink as shown in FIG. First, the first winding force transmission gear 15 is released from the mesh with the rack 5, and the second winding force transmission gear 16 is meshed with the rack 5. Then, in this state, when the carriage 5 is moved to the left (carriage return direction) as shown by the arrow in FIG. 3, the second winding force transmission gear 16 meshed with the rack 5 causes the carriage 5 to move. It rotates counterclockwise as it travels, and the take-up gear 1
2 is rotated in the counterclockwise direction together with the take-up spool 11, whereby the ink ribbon can be further wound around the take-up reel in the ribbon cassette (not shown). Can be reached.

FIG. 4 shows that when the multi-time ribbon is completely wound up on the take-up reel, the multi-time ribbon is automatically printed when the unattended printing is performed using the multi-time ribbon which can be used plural times. This figure shows the rewinding operation of the ink ribbon in the non-printing state, which is applied when it is necessary to rewind the sheet. In this state, the thermal head 4 is separated from the platen 1. Further, in this state, the first unwinding force transmission gear 35 meshes with the rack 5.

In this state, the carriage 5 is moved to the position shown in FIG.
When you move to the left as shown by the arrow in the
The first rewinding force transmission gear 35 meshing with the carrier 5 rotates counterclockwise as the carriage 5 travels, causing the rewinding gear 32 to rotate clockwise with the supply spool 31. The ink ribbon can be rewound on the supply reel. Further, even if the carriage 5 is moved to the final position in the left direction, if the entire amount of the ink ribbon is not rewound, the disc cam 6 is driven to drive the first winding as shown in FIG. The return force transmission gear 35 is released from the mesh with the rack 5, and the second
The rewinding force transmission gear 36 is meshed with the rack 5. Then, in this state, when the carriage 5 is moved to the right as shown by the arrow in FIG. 5, the second rewinding force transmission gear 36 meshed with the rack 5 is moved counterclockwise by the movement of the carriage 5. To rotate the rewinding gear 32 together with the supply spool 31 in the clockwise direction.
The ink ribbon can be further rewound on a supply reel in a ribbon cassette (not shown).

In this way, by alternately continuing the states of FIGS. 4 and 5, the entire amount of the ink ribbon can be rewound.

As described above, according to this embodiment, the ink ribbon can be wound and unwound stably by meshing with the rack 5.

Therefore, when a color ink ribbon in which a plurality of colors of ink are repeatedly deposited in order in the running direction is used, the ink of a predetermined color is printed after printing is completed and before the next printing is started. It is possible to wind a length of ink ribbon so that the ribbon can be used. Further, when unattended printing is performed using a multi-time ribbon that can be used multiple times, the ink ribbon can be automatically rewound when all the ink ribbon is wound around the winding shaft.

The present invention is not limited to the above-mentioned embodiment, but various modifications can be made if necessary.

For example, in the case of winding only according to the first aspect, the rewinding gear 32 for rotating the supply spool 31 in the rewinding direction, the second support lever 33, and other components are added to the configuration of the embodiment. Just delete it. In the case of only rewinding according to claim 2, the configuration for performing the rewinding at the time of carriage return such as the second rewinding force transmission gear 16 is deleted from the configuration of the embodiment, and the ink ribbon is rewound. It may be possible to perform it only during printing.

Further, in the embodiment, the bobbin on the carriage side is fitted to the pulley on the ribbon cassette side to transmit the rotational force. However, the bobbin on the carriage side is directly meshed with the winding force transmitting gear and the rewinding force transmitting gear. It is also possible to provide gears on the side of the ribbon cassette, and house a small diameter winding shaft and rewinding shaft rotated by these gears in the ribbon cassette. Therefore, in the claims, the winding shaft and the rewinding shaft are used as a general term for those that wind the ink ribbon, but the winding reel and the rewinding shaft are not limited to these winding shafts and rewinding shafts. It goes without saying that the rewind reel (supply reel) and the like are also included in the technical scope of the claims.

[0049]

As described above, according to the ink ribbon drive device of the first aspect of the present invention, the ink ribbon can be stably wound while the carriage is traveling in both directions.

Further, according to the ink ribbon drive device of the second aspect of the present invention, the ink ribbon rewinding can be stably performed when the carriage is traveling in both directions.

Further, according to the ink ribbon drive device of the third aspect of the present invention, either winding or rewinding of the ink ribbon can be selectively and stably performed when the carriage is running in both directions.

[Brief description of drawings]

FIG. 1 is a plan view of a printed state showing an embodiment of the present invention.

FIG. 2 is a plan view of an ink ribbon wound state at the time of head-up of the embodiment of FIG.

FIG. 3 is a plan view of an ink ribbon wound state at the time of carriage return in the embodiment of FIG.

FIG. 4 is a plan view of an ink ribbon rewinding state at the time of carriage return in the embodiment of FIG.

5 is a plan view of the ink ribbon rewound state at the time of head-up of the embodiment of FIG.

[Explanation of symbols] 1 platen 2 carriage 4 thermal head 5 rack 6 disk cam 11 take-up spool 12 take-up gear 13 first support lever 15 first take-up force transmission gear 16 second take-up force transmission gear 17, 18, 19 Idler 20 First Transmission Means 21 Cam Follower 31 Supply Spool 32 Rewinding Gear 33 Second Support Lever 35 First Rewinding Force Transmission Gear 36 Second Rewinding Force Transmission Gear 37, 38, 39 Idler 40 Second Transmission Means 41 Cam Follower

Claims (3)

[Claims] 1. A carriage comprising: a thermal head which can be brought into contact with and separated from a platen; and a ribbon cassette which accommodates an ink ribbon, which is sandwiched between the thermal head and the platen together with a sheet, around a supply shaft and a take-up shaft. In the thermal transfer printer mounted on the rack, a rack arranged in the traveling direction of the carriage, a winding gear for rotating and driving the winding shaft, and a rack selected when the carriage travels in one direction. Transmission gear having a pair of transmission gears capable of meshing with each other, transmitting the rotation of each transmission gear to the winding gear, a support lever supporting this transmission means, and any one of the transmission gears is selected. And a cam member for controlling the rotational position of the support lever so as to be meshed with the rack, the ink in the thermal transfer printer. Ribbon drive. 2. A carriage comprising: a thermal head which can be brought into contact with and separated from a platen; and a ribbon cassette which accommodates an ink ribbon, which is sandwiched between the thermal head and the platen together with a paper, around a supply shaft and a take-up shaft. In the thermal transfer printer mounted on the rack, a rack arranged in the traveling direction of the carriage, a winding gear that drives the winding shaft to rotate, and a rack that selectively meshes with the rack and is attached to the winding gear. And a pair of transmission gears that can selectively mesh with the rack when the carriage travels in any one direction. The transmission means for transmitting the rotation of each of the transmission gears to the supply gear, the support lever for supporting the transmission means, and any one of the transmission gears are selectively connected to the front side. An ink ribbon drive device in a thermal transfer printer, comprising: a cam member for controlling the rotational position of the support lever so that the support lever can be meshed with the rack. 3. A carriage comprising: a thermal head which can be brought into contact with and separated from a platen; and a ribbon cassette which accommodates an ink ribbon, which is sandwiched between the thermal head and the platen together with paper, around a supply shaft and a take-up shaft. In a thermal transfer printer mounted on, a rack arranged in the traveling direction of the carriage, a winding gear for rotating and driving the winding shaft, and a driving shaft for rotating the supply shaft in a rewinding direction of the ink ribbon. And a pair of winding force transmitting gears that can selectively mesh with the rack when the carriage travels in one direction, and the rotation of any one of the winding force transmitting gears is changed. First transmission means for transmitting to the winding gear to rotate the winding shaft in the winding direction, a first support lever for supporting the first transmission means, and the carriage A pair of rewinding force transmission gears that can selectively mesh with the rack when traveling in any one of the directions, and transmits the rotation of any one of the rewinding force transmission gears to the rewinding gear. The second transmission means for rotating the winding shaft in the rewinding direction, the second support lever for supporting the second transmission means, and one of the transmission gears are selectively engaged with the rack. An ink ribbon drive device in a thermal transfer printer, characterized in that a cam member for controlling the rotational positions of both support levers is provided.