JPH07125363A - Heat-sensitive transfer printer - Google Patents

Abstract

PURPOSE:To obtain a printer wherein a misregistration does not occur, irrespective of the diameter of a roll drawing out a thermal transferred sheet, and a desired quality image can be obtained. CONSTITUTION:At least one nip roller 1 is arranged between a roll 9 drawing out a thermal transferred sheet 4 and a platen roller 2. A thermal transfer sheet 3 is conveyed, the thermal transferred sheet 4 is drawn out of the roll 9 by driving the nip roller 11, sent to the platen roller 2 and after printing between the platen roller 2 and a thermal head 1, sent to the cutter 10 by the platen roller 2. In this case, the nip roller 11 is turned at a fixed speed, and a linear velocity of the nip roller 11 is made slower than the linear velocity of the platen roller 2. Tension of the thermal transferred sheet 4 becomes constant between the nip roller 11 and platen roller 2, feed irregularity following a change of the diameter of the roll 9 is dissolved and an image free from estimation discrepancy can be recorded.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a thermal transfer printer used for recording an image by melt transfer or sublimation transfer.

[0002]

2. Description of the Related Art Heretofore, as a thermal transfer printer of this type, a type in which a thermal transfer sheet is continuously fed from a roll has been used. FIG. 1 shows an example of such a thermal transfer printer. In this thermal transfer printer, the thermal head 1 and the platen roller 2 of the recording unit are arranged to face each other, and the thermal transfer sheet 3 and the thermal transfer sheet 4 are conveyed so as to pass between them. That is, the thermal transfer sheet 3 housed in the cassette case 5 is fed from the supply side bobbin 6 so as to be wound on the winding side bobbin 7, and the thermal transfer sheet 4 is delivered from the roll 9 wound on the bobbin 8. To transport. Then, the thermal head 1 is pressed against the thermal transfer sheet 4 via the thermal transfer sheet 3, and in this state, the platen roller 2
Is rotated to convey the thermal transfer sheet 3 and the thermal transfer sheet 4, and the thermal head 1 is energized to generate heat in a plurality of heating resistors in accordance with image information while being synchronized with the feeding speed of the thermal transfer sheet 4. An image is recorded on the heat-transferred sheet 4, and the printed heat-transferred sheet 4 is cut into a predetermined length by a cutter 10 and discharged.

[0003]

In the above-mentioned conventional thermal transfer printer, when the number of screens of the heat transfer sheet 4 wound around the bobbin 8 is increased in order to reduce the frequency of replacement of the roll 9, the diameter of the roll 9 before and after use is reduced. The fluctuation ratio becomes large. Therefore, when the platen roller 2 alone is used for conveyance as shown in FIG.
In the portion pressed by, the fluctuation of the tension (back tension) acting on the heat-transferred sheet 4 in the direction of the roll 9 becomes large and the conveyance becomes unstable. Therefore, misregistration due to uneven feeding occurs and desired quality is obtained. There was a problem that the image of could not be recorded.

The present invention has been made in view of the above problems, and an object of the present invention is to obtain an image of desired quality without misregistration regardless of the diameter of the roll for feeding the heat transfer sheet. It is to provide a thermal transfer printer capable of recording.

[0005]

In order to achieve the above object, the present invention provides at least a conveying means for feeding a thermal transfer sheet from a supply side bobbin to convey it to a winding side bobbin, and a thermal transfer sheet. Conveying means for feeding the sheet out of the roll and conveying it, a platen roller arranged in the conveyance path of the thermal transfer sheet and the thermal transfer sheet, and the thermal transfer sheet and the thermal transfer sheet to be conveyed are pressed against the surface by the platen roller, In the heat-sensitive transfer printer having a thermal head for recording an image on the heat-transferred sheet, the heat-generating resistor generates heat in accordance with image information, and at least one roller is provided between the roll for feeding the heat-transferred sheet and the platen roller. It is characterized in that a nip roller is provided.

[0006]

In the thermal transfer printer of the present invention having the above-mentioned construction, the nip roller arranged between the roll of the heat transfer sheet and the platen roller serves to make the back tension of the heat transfer sheet constant. That is, by rotating the nip roller at a predetermined speed and making the linear speed of the nip roller smaller than the linear speed of the platen roller, a constant tension acts on the heat-transferred sheet conveyed between the nip roller and the platen roller. .

[0007]

FIG. 2 shows an embodiment of a thermal transfer printer according to the present invention, in which parts common to those of the prior art example are designated by the same reference numerals.

In the thermal transfer printer shown in FIG. 1, the thermal transfer sheet 3 is fed from the supply side bobbin 6 and wound on the winding side bobbin 7 by the thermal transfer sheet conveying means, and the thermal transfer sheet is conveyed from the roll 9 by the thermal transfer sheet conveying means. The sheet 4 is fed out and conveyed, and both are passed under pressure between the platen roller 2 and the thermal head 1, and in that state, heat is selectively applied by the thermal head 1 to record an image on the thermal transfer sheet 4. After that, the heat-transferred sheet 4 is cut into a predetermined length by a cutter 10 and discharged, and a nip roller 11 is arranged between a roll 9 for feeding the heat-transferred sheet 4 and the platen roller 2. ing.

By providing the nip roller 11 in the conveying path of the heat transfer sheet 4 as described above, the heat transfer sheet 4 is fed from the roll 9 by the driving of the nip roller 11 and sent toward the platen roller 2 and the platen roller 2. After being printed between the thermal heads 1, it is sent to the cutter 10 by the platen roller 2. In this case, the nip roller 11 is rotated at a predetermined speed, and the linear speed of the nip roller 11 is made smaller than that of the platen roller 2. As a result, even if the diameter of the roll 9 is gradually reduced, the heat-transferred sheet 4 can be transferred to the nip roller 1
The tension between the platen roller 1 and the platen roller 2 becomes constant, and the uneven feeding by the platen roller 2 due to the change in the diameter of the roll 9 is eliminated, and as a result, an image without misregistration is recorded.

[0010]

As described above, the heat-sensitive transfer printer of the present invention is configured so that at least one nip roller is arranged between the roll for feeding the heat-transferred sheet and the platen roller. Since the image can be recorded while a constant tension is applied to the heat transfer sheet, it is possible to record an image of desired quality without misregistration.

[Brief description of drawings]

FIG. 1 is a schematic view showing an example of a conventional thermal transfer printer.

FIG. 2 is a schematic view showing an embodiment of a thermal transfer printer according to the present invention.

[Explanation of symbols]

 1 Thermal Head 2 Platen Roller 3 Thermal Transfer Sheet 4 Thermal Transfer Sheet 6 Supply Side Bobbin 7 Winding Side Bobbin 8 Bobbin 9 Roll 10 Cutter 11 Nip Roller

Claims (1)

[Claims] 1. At least a conveying means for feeding out a thermal transfer sheet from a supply side bobbin and winding it up to a winding side bobbin, a conveying means for feeding out a thermal transfer sheet from a roll and conveying it, a thermal transfer sheet and a thermal transfer sheet. The platen roller arranged in the middle of the sheet conveying path, the conveyed thermal transfer sheet and the thermal transfer sheet are pressed against the surface by the platen roller, and a plurality of heating resistors generate heat according to the image information. In a thermal transfer printer equipped with a thermal head for recording an image on
A thermal transfer printer, wherein at least one nip roller is provided between a roll for feeding out a thermal transfer sheet and a platen roller.