JPS63309483A - Thermal transfer recorder - Google Patents

Abstract

PURPOSE:To reduce the torque required of a motor for driving a take-up roll, by providing a driving means for releasing a braking action of a second brake device at the time of taking up an ink sheet by separating a thermal head from a platen roller. CONSTITUTION:A second brake device 19 and a thermal head 2 are rotated by a cam 23, that is, end parts 30 and 31 are pushed upward by the cam 23 when the cam 23 is rotated about a shaft 22. As a result, the thermal head 2 and the second brake device 19 are rotated respectively about shafts 25, 26, whereby the thermal head 2 is separated from a platen roller, whereas the second brake device 19 is separated from a payout roll 9. At the time of starting thermal transfer, the cam 23 is rotated to bring the thermal head 2 and the second brake device 19 into contact with the platen roller 3 and the payout roll 9, respectively. Then, the platen roller 3 is rotated in the direction of an arrow B, and thermal transfer is started.

Description

[Detailed description of the invention] [Industrial application field] This invention relates to improvements in thermal transfer recording devices.

[Prior Art] Color image recording by thermal melting or sublimation thermal transfer is performed using an ink sheet on which inks of four colors, yellow, magenta, cyan, and black are applied in tandem in this order, for each color. A color image is created by transferring it to paper.

In this device, the recording paper is returned to its original position each time the transfer of each color is completed. FIG. 3 shows the configuration of a conventional thermal transfer recording apparatus.

In the figure, an ink sheet (1) is supplied from a supply roll (9), sent in the direction shown by the arrow (A), passes between a thermal head (2) and a platen roller (3), and then passes through a guide roller (7). 0 is then wound onto the take-up roll (8).
The take-up roll (8) is driven by a motor (15) via gears (14a), (14b) and (14c). As shown in Fig. 4, the ink sheet (1) includes a reference mark (S) for positioning the ink sheet, yellow ink (Y), magenta ink (M), cyan ink (C),
and black ink (Y) are arranged in this order, and a reference mark (S) is provided again after the sodomy ink.

The ink sheet (1) is configured to stop at a predetermined position when the reference mark (S) is detected by the sensor (6). Ink sheet (1) supply roll (9
) is provided with a brake a side (10) on its shaft. The brake mechanism (10) includes a felt (11) attached to an arcuate portion of a leaf spring (12) having an arcuate end.
The arcuate concave surface of the felt (11) is pressed against the shaft of the supply roll (9) with a predetermined pressure.The zero-winding roll (8) is equipped with a torque limiter (13).
is provided to prevent the winding force from exceeding a predetermined value. The recording paper (5) is supplied from a recording paper stocker (not shown) and passes between the platen roller rough 3) and the pinch roller (4) and between the platen roller (3) and the thermal head (2) in the direction of arrow (B). Sent in the direction shown.

Next, the operation of this conventional example will be explained. The ink sheet (1) is placed on a take-up roll (
The thermal head (2) and platen roller (3) are gradually fed out from the supply roll (9) by the tensile force of
The winding roll (
8). When the thermal head (2) is in contact with the platen roller (3) to perform thermal transfer, the conveyance speed of the ink sheet 1-(1) is controlled by the rotation of the platen roller (3). Therefore, the torque limiter (13
) is causing slippage. On the other hand, when the thermal head (2) is away from the platen roller (3) and thermal transfer is not performed, there is no slippage in the torque limiter (13) and the ink sheet 1-(1) is sent out during the thermal transfer.
) is longer than the length per unit time of 1-(1
) is wound up.

The brake device (lO) applies a predetermined braking force to the supply roll (9), and this braking force applies a predetermined tension to the ink sheet (1) being wound up on the take-up roll (8).

This tension is set to a value that does not cause wrinkles on the ink sheet (1) during thermal transfer, and is set smaller than the tension determined by the set torque of the torque limiter (13).

When performing thermal transfer recording on recording paper, first the thermal head (2) is separated from the platen roller (2) by a drive mechanism (not shown), and the ink sheet (1) is moved by the motor (15) as shown by the arrow (A). transport in the direction.

The sensor (6) detects the fiducial mark (S) of Inksey 1-(1).
) is detected, the rotation of the motor (15) is stopped by a control circuit (not shown). Next, one sheet of recording paper (5) is fed out from a supply tray (not shown), and the platen roller (3) and the pinch It is sent to the recording start position by the roller (4). The thermal head (2) is connected to the platen roller (
3) and the thermal head (2) and platen roller (
A drive mechanism (not shown) rotates the platen roller (3) in the direction shown by the arrow (B) to perform thermal transfer. When the first color thermal transfer is completed, the thermal head (2)
is again separated from the platen roller (3), and the recording paper (5) is returned to the recording start position by the platen roller (3) and the pinch roller (4). At this time, the second color of ink on the ink sheet (1) has come to the recording start position, and thermal transfer is performed again by the same process as the first color thermal transfer. In this way, as shown in FIG. 4, the ink sheet (1) is sent in the direction shown by the arrow (C), and thermal transfer of each color is performed in sequence.

[Problem 1 to be solved by the invention In the conventional thermal transfer recording device described above, the ink sheet (
1) is the driving force of the platen roller (3) and the take-up roll (8).
) is pulled in the direction of arrow (A). On the other hand, the supply roll (9) is braked by a brake mechanism (10), and the braking force of the brake mechanism (lO) is set to an appropriate tension that does not cause wrinkles on the ink sheet during thermal transfer. However, when winding up the ink sheet (1) with the thermal head (2) separated from the platen roller (3), the rotational force of the platen roller (3) is not applied to the ink sheet (1) and the ink sheet ( 1) is wound up only by the winding force of the winding roll (8). Therefore, the torque of the motor (15) that drives the take-up roll (8) must be greater than when thermal transfer is being performed.
There has been a problem in that a motor larger than the motor having the necessary torque must be used during thermal transfer in order to convey the image. Further, as a result of using a large motor, the quality of the drive system becomes large, and there is a problem in that the stopping position when the ink sheet (1) is stopped after detecting the reference mark (S) varies.

[Means for Solving the Problems] The thermal transfer recording device of the present invention includes a first brake device and a second brake device that brake an ink sheet supply roll, and has an ink sheet winding mechanism driven by a motor. A roll and a thermal head are provided on the outer periphery of the platen roller that conveys the recording paper to closely spread and thermally transfer the ink sheet onto the recording paper, and when the thermal head is separated from the platen roller to wind up the ink sheet, a second brake device is provided. It is equipped with a driving means for releasing the brake.

[Operation] When the thermal head is not in contact with the platen roller, the braking of the second brake device is released, so the braking force of the supply roll becomes weaker, and the required torque of the motor that drives the take-up roll becomes smaller.

[Example] In Figure 1, which shows the configuration of an example of the present invention,
The ink sheet (1) is supplied from a supply roll (9), passes between a thermal head (2) and a platen roller (3), and is taken up by a take-up roll (8). Supply roll (9)
is provided with a first brake device W1 (16) and a second brake device (19), both of which are equipped with an ink sheet (
1) is fed in the direction of arrow (A), the supply roll (9
) to provide braking force. The first brake device (16) is always in contact with the supply roll (9) and provides a constant braking force. There is also a second brake device (
19) is rotatably supported by a shaft (26),
A braking force is applied by a spring (29). →ノ°−
The round head (2) is supported by a shaft (25) and is supported by a spring (
28) applies force to the platen roller (3). The tAI diagram shows the state when this thermal transfer recording device is performing thermal transfer, and the platen roller (
3) and the ink sheet (1), the recording paper (5) is fed by the pinch roller (4), and the platen roller (3)
) is conveyed by the rotation of the zero winding roll (8), which is conveyed by the rotation of the gear (
A torque limiter (13) is provided on the zero take-up roll (8) which is driven by the motor (15) via the wind-up roll (14a), (14b) and (14c).
8) The winding force is limited so as not to exceed a predetermined value. The second brake device (19) and the thermal head (2) are configured to be rotated by a cam (23), and when the cam (23) rotates about the shaft (22), the respective ends (30) ) and (31) are cams (23)
is pushed upward. As a result, the thermal head (2) and the second brake device (19) each have a shaft (
25), (26), the thermal head (2) leaves the platen roller and the second braking device l1 (19) leaves the supply roll (9). This state is shown in FIG.

Next, the operation of this embodiment will be explained. Prior to the start of thermal transfer, in the state shown in FIG. 2, the ink sheet (1) is conveyed from the supply roll (9) in the direction of arrow (A) and wound up by the take-up roll (8). At this time, only the brake device (16) is acting on the supply roll (9), and the ink sheet (1) is subjected to relatively small tension. The sensor (6) detects the reference mark (
When S) is detected, the ink sheet (1) stops. On the other hand, the recording paper (5) is held between the platen roller (3) and the pinch roller (
4) and positioned at a predetermined position. When starting thermal transfer, the cam (23) rotates, the thermal head (2) contacts the platen roller (3) as shown in FIG. 1, and the second brake device (19) contacts the supply roll (9).
). Then, the platen roller (3) rotates in the direction shown by arrow B, and thermal transfer is started. In this state, the ink sheet (1) is driven by both the driving force of the platen roller (3) and the winding force of the take-up roll (8),
The supply roll (9) is provided with braking force by a first braking device (16) and a second braking device (19).

As a result, the tension of the ink sheet (1) is increased by the platen roller (
3) and the supply roll (9), the ink sea increases)
(1) is made to have an optimal tension that does not cause wrinkles. Also, at this time, the tension applied to the ink sheet (1) between the platen roller (3) and the take-up roll (8) is only the winding force of the take-up roll (8), so in the case shown in FIG. Equal to tension.

[Effect of the invention] According to this invention, the reference mark (
When transporting the ink sheet (1) in a state where the thermal head (2) is not in contact with the platen roller (3), such as when detecting S), two sets of brake devices installed on the supply roll (9) are used. The cam (23) releases the second brake device (19) to weaken the braking force, and the thermal head (2) contacts the platen roller (3) to apply the driving force of the platen roller (3). When the supply roll (
The braking force of 9) is increased by a second brake device (19) so that an optimum tension is applied to prevent the ink sheet (1) from wrinkling. In this case, the driving force of the platen roller (3) is added to the tensile force of the take-up roll (8) to the ink sheet (1), so there is no need to increase the driving force of the take-up roll (8). As a result, the drive motor (15) for the take-up roll (8) can be small-sized, and the thermal transfer recording apparatus can be constructed in a compact size. Furthermore, by using a small drive motor, the quality of the drive system is reduced, and the positioning accuracy of the ink sheet (1) is improved.

[Brief explanation of the drawing]

FIG. 1 is a side view showing the configuration of an embodiment of the present invention, FIG. 2 is a side view showing the embodiment shown in FIG. 1 in a state where thermal transfer is not performed, and FIG. 3 is a conventional thermal transfer recording apparatus. 4 is a side view showing the structure of the ink sheet (1), and FIG. 4 is a plan view showing the structure of the ink sheet (1) commonly used in the present invention and the conventional example. 1: Ink sheet 2: Thermal head 3 Nibraten roller 8: Take-up roll 9: Supply roll 15: Motor 16: First brake device 19: Second brake device 23: Cam 2 Procedural correction group (spontaneous)

Claims (1)

[Claims] (1) A first braking device that constantly applies braking force to the ink sheet supply roll, a motor that drives the take-up roll that winds up the ink sheet, a platen roller that conveys the recording paper, and a brake that applies braking force to the recording paper at the outer periphery of the platen roller. A thermal head that thermally transfers the ink sheet by keeping it in close contact with the platen roller. A second brake device that applies braking force to the ink sheet supply roll when the thermal head is in close contact with the platen roller. A second brake device that separates the thermal head from the platen roller and winds up the ink sheet. A thermal transfer recording device comprising a drive means for releasing the braking of the second brake device.