JPH05293981A - Thermal transfer printer - Google Patents

Abstract

PURPOSE:To prevent the generation of wrinkles in transfer paper, to obtain good printing quality and to enable cost reduction. CONSTITUTION:In a thermal transfer printer 1 wherein a thermal head 8 is brought into contact with the recording paper 3 wound around the outer periphery of a platen roller 7 under pressure through transfer paper 9 to perform transfer, the winding angle alpha of the transfer paper 9 to the outer periphery of the platen roller 7 is set to 30-90 deg. so as to prevent the generation of wrinkles in the transfer paper and the generation of printing pitch irregularity due to the high taking-up tension of the transfer paper.

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 a transfer paper is pressure-bonded to a recording paper wound around the outer periphery of a platen roller.

[0002]

2. Description of the Related Art In recent years, thermal transfer printers have been widely used. This thermal transfer printer melts the ink on the transfer paper by the heat of the thermal head (heat melting type) or sublimates it (thermal sublimation type) to transfer the ink according to the character and image information to a desired position on the recording paper. Transfer is performed in accordance with a signal, and a roll recording paper is known as this recording paper. FIG. 3 is a schematic diagram showing a thermal transfer printer according to an embodiment of the present invention and a conventional example which will be described later.

As shown in the figure, a conventional thermal transfer printer 21 comprises a platen roller 7, a linear thermal head 8, a cutter 14, a case 15, a control circuit 16, an operation control microcomputer 17, a display panel 18, and the like. Has been done. In this printer 21, the recording paper 3 is placed around the roll 4.
A roll recording paper 2 is used, which is wound in a roll shape in the longitudinal direction. The center hole of the roll 4 is loaded on the roll recording paper shaft 5, the recording paper 3 is sequentially pulled out from the roll-shaped starting end side, and the back surface of the recording surface 3a is passed through the recording paper roller (A) 6A. It is wound in a substantially U-shape so as to follow the outer periphery of the platen roller 7, and is cut by the cutter 14 one screen at a time via the recording paper roller (B) 6B.
The recorded recording paper 3b is ejected out of the case 15.

Transfer paper shafts (A) 11A and (B) 11
A transfer paper 9 is wound around each of B, and a supply reel 10A that gives a back tension to the transfer paper 9 and a take-up reel 10B that gives a take-up tension are loaded on the transfer paper 9. The transfer paper 9 is wound between the reels 10A and 10B. Transfer paper 9
Is a pair of transfer paper rollers (A) 23A and (B) 23B
Positioned by the platen roller 7
Is always pressure-bonded onto the recording surface 3a of the recording paper 3 on the outer periphery of the recording paper 3 (in the past, the transfer paper 9 was pressure-bonded only at the time of recording, but recently, due to the simplification of the mechanism, Method has appeared), and at the time of recording, the thermal head 8 is pressed onto the recording surface 3a via the transfer paper 9.

The heat generated by the energization control of the thermal head 8 causes the color ink on the transfer paper 9 to move on the recording surface 3a of the recording paper 3 in the directions indicated by the arrows in FIG. Along with this, each line is transferred. At this time, a torque limiter 12 is arranged between the transfer paper winding motor (not shown) and the transfer paper shaft (B) 11B in order to prevent the occurrence of print pitch unevenness due to a large transfer paper winding tension described later. The above-mentioned operation is performed under the control of the control circuit 16 in accordance with the instruction from the microcomputer 17, and the operation status is displayed on the display panel 18.

FIG. 4 is a block diagram showing the essential parts of an example of a conventional thermal transfer printer. As shown in the figure, in the above-described conventional thermal transfer printer 21, the following two reasons are set.
The wrap angle β of the transfer paper 9 around the platen roller 7 is less than 20 °. The first reason is
The second reason is to reduce the load amount of the transfer paper 9 in the traveling direction, and the second reason is the supply reel 10A and the take-up reel 10.
B, because the transfer paper 9 is housed in a cartridge (not shown) for the sake of easy handling, the pressure bonding mechanism of the transfer paper 9 is not complicated.

[0007]

In the conventional thermal transfer printer 21 having the above-mentioned configuration, wrinkles are generated due to the tension difference of the transfer paper 9 in the paper width direction (the wrinkles of the transfer paper 9 are not generated). , Adversely affecting print quality such as print image quality), the transfer paper rollers (A) 23A and (B) with respect to the platen roller 7
Since the parallelism accuracy of 23B is required, there is a problem that cost of parts and assembly / adjustment man-hours are required, resulting in high cost. Further, the supply reel 10A and the take-up reel 10
B, when the transfer paper 9 is the above-mentioned cartridge type,
When there is a large difference in tension between the back tension by the supply reel 10A and the take-up reel by the take-up reel 10B in the paper width direction, and when there is a large pressure contact difference in the paper width direction of the thermal head 8 and a large print density difference in the paper width direction. Is the transfer paper roller (A) 2
In some cases, the tension difference absorption by 3A and (B) 23B is insufficient, and there is a problem that wrinkles occur on the transfer paper 9.

The present invention has been made in view of the above points, and provides a thermal transfer printer which does not cause wrinkles on a transfer sheet, can obtain good print quality, and can reduce the cost. The purpose is.

[0009]

In the thermal transfer printer of the present invention, a thermal head is pressed against a recording paper wound around the outer periphery of a platen roller via the transfer paper, and the ink of the transfer paper is applied to the recording paper. A thermal transfer printer for transferring, wherein at least when the transfer paper moves relative to the outer circumference of the platen roller, the transfer paper is pressure-bonded to the recording paper wound around the outer circumference of the platen roller. In the thermal transfer printer described above, the above-described object is achieved by configuring the wrapping angle of the transfer paper around the outer periphery of the platen roller to be approximately 30 to 90 degrees.

[0010]

EXAMPLE An example of the present invention will be compared and explained under the same conditions as in the case of the above-mentioned conventional example. As shown in FIG. 3, the thermal transfer printer 1 according to the embodiment of the present invention is, as compared with the printer 21 according to the conventional example described above, the positions of the transfer paper rollers (A) 13A and (B) 13B as will be described later. However, the description of the same parts as those in the conventional example will be omitted.

FIG. 1 is a block diagram showing the essential parts of an embodiment of a thermal transfer printer of the present invention. As shown in the figure, in the thermal transfer printer 1 of the embodiment of the present invention, the transfer paper 9 is wound around the platen roller 7 and positioned by the transfer paper rollers (A) 13A and (B) 13B. The angle α is 30 ° to 90 °. As will be described later, the range of the winding angle α is a range in which the above-mentioned wrinkles of the transfer paper 9 do not occur, and moreover, print pitch unevenness due to the large transfer paper winding tension does not occur.

FIG. 2 is a graph for explaining the relationship between the number of wrinkles of transfer paper, the transfer paper winding reel winding torque, and the transfer paper winding angle α in the printer of FIG. First,
The measurement conditions and measurement method of the graph of FIG. 2 will be described. The platen roller 7 has a hardness of 70 ° on the outer periphery and a thickness of 2 mm.
The outer diameter is φ20.
As the recording paper 3 and the transfer paper 9, a sublimable recording paper and transfer paper set (model number BC-P102BJ) manufactured by Dai Nippon Printing Co., Ltd. was used. Then, the transfer paper 9 is pressure-bonded while the recording paper 3 is wound and fixed on the outer periphery of the platen roller 7, and the take-up reel 10 of the transfer paper 9 is attached.
The relationship between the winding torque of B and the transfer paper winding angle α was measured. In this case, the diameter of the winding roll on the winding reel 10B was measured at the maximum (φ35 mm) and the minimum (φ20 mm). In the printer 1 described above, from the experimental results, when the transfer paper take-up reel take-up torque is 150 gf-cm or more, print pitch unevenness occurs due to a large transfer paper take-up tension. Is caused by)
Since it was confirmed that the slip limit torque of the torque limiter 12 was set to 150 gf-cm.

Next, the thermal head 8 (model number FF4401A manufactured by TDK Co., Ltd.) is 5 kgf as a whole.
The pressure was applied to the transfer paper 9 with the above pressure to perform front surface recording so that the maximum print density was obtained, and the relationship between the number of wrinkles of transfer paper per A4 size screen and the transfer paper winding angle α was measured. Then, the graph of FIG. 2 is a summary of the above measurement results.

As shown in the figure, in the relationship curve between the transfer paper take-up reel take-up torque and the transfer paper take-up angle α, when the take-up roll is maximum (φ35 mm), this take-up angle α is 90 °.
In the above, since the slip limit torque of 150 gf-cm of the torque limiter 12 is exceeded, the transfer paper 9
It becomes impossible to wind up. In other words, the print pitch unevenness occurs due to the large transfer paper winding tension. On the other hand, in the relationship curve between the number of wrinkles of transfer paper and the wrapping angle α of transfer paper, the larger the wrapping angle α, the more the tension difference in the paper width direction is absorbed by the abrasion resistance, and the number of wrinkles decreases. Wrinkles do not occur above 30 °. Therefore, the transfer paper winding angle α is 30 ° to 9 °.
The range of 0 ° is an OK range where good print quality can be obtained.

The thermal transfer printer 1 of one embodiment of the present invention having the above-mentioned configuration is the above-mentioned conventional printer 21.
In comparison with the above, the transfer paper wrapping angle α is set to a range where wrinkles do not occur on the transfer paper 9 and a range where print pitch unevenness due to a large winding tension of the transfer paper 9 does not occur, as described above. Is improved, and good print quality can be obtained. Also, the transfer paper rollers (A) 13A and (B) 1
Since 3B does not require high precision such as adjustment, cost can be reduced.

[0016]

The thermal transfer printer of the present invention having the above-described structure has improved print quality and cost reduction. Therefore, the function of the printer is improved and the cost performance is improved.

[Brief description of drawings]

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

FIG. 2 is a graph for explaining the relationship between the number of wrinkles of transfer paper, the transfer paper take-up reel winding torque, and the transfer paper winding angle α in the printer of FIG.

FIG. 3 is a schematic diagram showing a thermal transfer printer according to an embodiment of the present invention and a conventional example.

FIG. 4 is a configuration diagram showing a main part of an example of a conventional thermal transfer printer.

[Explanation of symbols]

 1 Thermal Transfer Printer 3 Recording Paper 7 Platen Roller 8 Thermal Head 9 Transfer Paper α Transfer Paper Wrapping Angle

Claims (1)

[Claims] 1. A thermal transfer printer which presses a thermal head onto a recording paper wound around the outer periphery of a platen roller via the transfer paper to transfer the ink of the transfer paper to the recording paper, wherein When the transfer paper moves relative to the outer circumference of the platen roller on the outer circumference of the platen roller, in the thermal transfer printer in which the transfer paper is pressure-bonded to the recording paper wound around the outer circumference of the platen roller, A thermal transfer printer characterized in that a winding angle around the outer periphery of the platen roller is approximately 30 to 90 degrees.