JP2905653B2 - Thermal transfer printer - Google Patents

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 and, more particularly, to winding of an ink ribbon using a driving force of a carriage and winding of an ink ribbon when a thermal head is in an up state. The present invention relates to a thermal transfer printer that stops printing.

[0002]

2. Description of the Related Art In general, in a thermal transfer printer in which an ink ribbon cassette containing a thermal transfer ink ribbon is mounted on a carriage and the carriage is reciprocated along a platen to perform printing, the ink ribbon is wound in accordance with the movement of the carriage. The ink ribbon needs to be taken up and down in conjunction with the up and down movement of the thermal head. Further, in such a thermal transfer printer, in order to simplify the mechanism, a separate driving source is not prepared for winding the ink ribbon, but the driving force of the carriage is used to drive the ink ribbon. In many cases, winding is also performed.

[0003]

However, in an apparatus utilizing the driving force of the carriage for winding the ink ribbon, when the thermal head is in the up state, such as during carriage return, the winding section of the ink ribbon is not used. And the drive system of the carriage, the ink ribbon may be loosened by the head-up operation from the head-down state to the head-up state after printing is completed. For this reason, when inserting new paper, the leading edge of the paper hooks on the ink ribbon, causing the ink ribbon to jam or performing the next printing operation.
There is a problem in that the distance from the time when the head for removing the slack of the ink ribbon is lowered to the time when printing is started needs to be long, and the width of the printer needs to be increased.

The present invention has been made to solve such a problem, and it is an object of the present invention to prevent the ink ribbon from becoming loose due to a head-up operation.

[0005]

According to the present invention, there is provided a thermal head comprising:
At the tip of the lever that is linked to the operation, the head is linked from the down state of the thermal head to the up state.
A winding spring that engages with the winding gear and rotates the winding gear in a direction of winding the ink ribbon is provided.

[0006]

The above means operates as follows.

Since the ink ribbon take-up member rotates in the direction in which the ink ribbon is taken up in conjunction with the head-up operation, the slack of the ink ribbon caused by the head-up operation is taken up by the ink ribbon take-up member. .

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A thermal transfer printer according to the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 are diagrams showing the configuration of an embodiment of the present invention. FIG. 1 shows a head down state and FIG. 2 shows a head up state. As shown in the figure, a carriage 4 reciprocally movable along the platen 1 is provided with a motor 4 for controlling the operation of moving the thermal head 3 to and from the platen 1 and controlling the winding of the ink ribbon. A transmission gear 6 is meshed with the output pinion gear 5 of the motor 4. The transmission gear 6 is meshed with a gear portion 8 formed on the outer peripheral surface of a cam 7. The upper surface of the cam 7 has a cam groove 9 for head contact / separation and a cam portion 10 for ribbon winding.
Are formed respectively.

Reference numeral 11 denotes a substantially L-shaped head pressure lever.
A pin 13 is formed at one end of the head pressure contact lever 11 so as to be swingable about a shaft 12.
The cam 7 is engaged with the head contact / separation cam groove 9.
The other end of the head pressure lever 11 is connected to the thermal head 3
The platen 1 of the thermal head 3 is brought into contact with the back surface of the head mounting base 3a via a spring (not shown) by the rotation of the head press-contact lever 11 accompanying the rotation of the cam 7.
Is performed. Further, a lever 14 is connected to the other end of the head press-contact lever 11, and this lever 14 is interlocked with the head press-contact lever 11.

The carriage 2 is provided with a driving gear 16 which always meshes with a rack 15 formed in the printer.
The swinging plate 18 that constitutes a transmission mechanism of the winding force of the ink ribbon is attached to the support shaft 17 so as to be swingable about the support shaft 17. A pin 19 is formed at one end of the swinging plate 18 so as to be engaged with the ribbon winding cam portion 10 of the cam 7. A transmission gear 20 meshed with the drive gear 16 is rotatably attached to the other end of the swing plate 18.

A carriage bobbin 21 and a delivery bobbin (not shown) for the ink ribbon are provided on the carriage 2, and can be engaged with the transmission gear 20 below the take-up bobbin 21. The take-up gear 23 is coaxially mounted via a friction mechanism (not shown).

Further, in the present embodiment, the carriage 2 is provided with a second winding bobbin 24 and a second delivery bobbin 25, respectively.
A second take-up gear 27 that meshes with the take-up gear 23 of the take-up bobbin 21 via a transmission gear 26 is coaxially attached to the bottom of the take-up bobbin 21 via a friction mechanism (not shown). The winding bobbin 21 and the second winding bobbin 24
The transmission gear 20 is rotated by the rotation of the cam 7 and the transmission gear 20 meshing with the winding gear 23 in conjunction with the down operation of the thermal head 3.

Further, a take-up spring 28 made of a leaf spring is attached to the tip of the lever 14 connected to the head pressure contact lever 11, and the tip 27a is
When the thermal head 3 is in the down state, the transmission gear 2
6 is engaged with the teeth of the transmission gear 26 when the thermal head 3 is in the up state.

Next, the operation of this embodiment will be described.

First, as shown in FIG. 1, since the pin 13 of the head pressure contact lever 11 is located at the innermost periphery of the head contact / separation cam groove 9 of the cam 7, the head pressure contact lever 11 is moved to the leftmost position. The head mounting base operates together with the head pressure contact lever 11 because of the swinging state.
Is held in a state of being pressed against the platen 1, a so-called head-down state. In this state, the pin 19 of the swing plate 18
Is located at the outermost periphery of the ribbon winding cam portion 10,
The swing plate 18 is in a state of being swung to the left most, and the transmission gear 20 is in a state of being meshed with the winding gear 23. In this state, when the carriage 2 moves along the platen 1 to rotate the drive gear 20 meshed with the rack, the take-up gear 23 is transmitted via the transmission gears 20 and 26.
Then, the second winding gear 27 rotates, and the operation of winding the ink ribbon is performed. As described above, in this state, the take-up spring 28 is held at a position away from the transmission gear 26.

Next, as shown in FIG. 2, the motor 4 is driven from the state shown in FIG.
When the cam 7 is rotated such that the pin 13 is located at the outermost periphery of the cam groove 9 for head contact / separation, the head pressure contact lever 11 swings rightward, and the thermal head 3 is detached from the platen 1 accordingly. (Head-up state). Further, since the pin 19 of the swinging plate 18 is located at the innermost periphery of the ribbon winding cam portion 10, the swinging plate 18 also swings rightward, and the engagement between the transmission gear 20 and the winding gear 23 is released. The transmission gear 20 is held at a position separated from the winding gear 23. In the operation from the state shown in FIG. 1 to FIG. 2, that is, in the up operation, the lever 14 moves in conjunction with the movement of the head pressure lever 11, so that the winding spring 28 attached to the lever 14 performs the up operation. The transmission gear 26 is rotated in the direction in which the ink ribbon is wound by a further up operation. The rotation of the transmission gear 26 is controlled by the winding gear 23.
Is transmitted to the second take-up gear 27, and the slack of the ink ribbon caused by the thermal head 3 being separated from the platen 1 is taken up.

Therefore, even if new paper is inserted in this state, the ink ribbon does not slack, so that the leading edge of the paper does not catch the ink ribbon.

In the head-up state shown in FIG. 2, the transmission gear 20 is separated from the take-up gear 23. Therefore, even if the carriage 2 is moved along the platen 1 in this state, the winding of the ink ribbon is stopped. No picking is done.

When the next printing is performed from the state shown in FIG. 2, the motor 4 is driven to select a predetermined position of the cam 7 so that the state shown in FIG. 1 is obtained. Since the slack of the ribbon has not occurred, it is not necessary to transfer the carriage in a blank printing state to remove the slack, and it is sufficient to transfer the blank print only in a through-up area for keeping the carriage speed constant.

[0021]

As described above, according to the present invention, the lever interlocking with the up / down operation of the thermal head is used.
At the front of the take-up gear in conjunction with the head-up operation of the thermal head from the down state to the up state.
In addition, by providing a take-up spring for rotating the take- up gear in a direction in which the ink ribbon is taken up, the slack of the ink ribbon can be taken up by the head-up operation, and a new sheet is inserted. In this case, the leading edge of the paper does not catch on the ink ribbon, which prevents jamming of the ink ribbon, and also performs an idle feeding operation to remove slack in the ink ribbon when performing the next printing operation. Therefore, the distance from the time when the head is lowered to the time when printing is started can be shortened, and as a result, the width of the printer can be reduced.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a main part showing an embodiment of a thermal transfer printer of the present invention, showing a head down state.

FIG. 2 is a configuration diagram of a main part showing one embodiment of the thermal transfer printer of the present invention, showing a head up-down state.

[Explanation of symbols]

 Reference Signs List 2 carriage 3 thermal head 4 motor 7 cam 11 head pressure contact lever 14 lever 18 rocking plate 20 transmission gear 23 winding gear 26 transmission gear 27 second winding gear 28 winding spring

Claims (1)

(57) [Claims] 1. A thermal head mounted on a platen,
The above-mentioned thermal head
Pressure contact for moving the pad to and away from the platen
Lever and a head pressure lever connected to the pressure lever.
Lever that works with the
A take-up gear for transmitting rotational force to the take-up bobbin;
And a cam for driving the pressure contact lever
In the thermal transfer printer is not performed the winding operation of the ink ribbon in the up state of the thermal head with utilizing the driving force of the carriage state performs the winding operation of the ink ribbon, the front portion of the lever Thermal < A take- up spring that engages with the take-up gear in conjunction with the head-up operation of the head from the down state to the up state, and rotates the take- up gear in a direction in which the ink ribbon is taken up. A thermal transfer printer comprising: