JPH05330105A - Thermal printer - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent the image receiving paper wound around the platen roller from skewing and causing misalignment, and not to deteriorate the color image. [Structure] An image receiving paper is wrapped around, an ink sheet is sandwiched between them, and pressed by a thermal head, and a heating element of the thermal head is selectively heated by an image signal to transfer ink,
It is characterized in that a guide groove 11 having the same width as the width of the image receiving paper to be printed is provided on the platen roller 1 for color printing by performing the transfer several times.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal printer,
Particularly, it relates to the shape of the platen roller of the thermal printer.

[0002]

2. Description of the Related Art Conventionally, in order to make a hard copy of a display image of a CRT or the like, a thermal printer has been used which records by superimposing an image receiving paper on an ink sheet and heating to transfer the dye from the ink sheet to the image receiving paper. Has been. In particular, a color thermal printer using a sublimation type ink sheet has recently attracted attention because it can obtain high image quality.

Conventionally, as an example of the platen roller used in this type of thermal printer, there is one shown in FIG. In FIG. 3, 6 is an image receiving paper which is fed for printing and is wound around the platen roller 10. 10 is the image receiving paper 6 wound around and the thermal head 2 (FIG. 2) is pressed to press the ink sheet 3 (FIG. 2). It is a platen roller adapted to transfer the dye (4) to the image receiving paper 6.

That is, in such a thermal printer having the conventional platen roller 10, after the image receiving paper is wound around the platen roller 10, the image receiving paper 6 is superposed on the ink sheet 3, and the thermal transfer is performed from the back surface of the ink sheet 3. The head 2 is heated according to an image signal, and dyes such as yellow, magenta, cyan, and black are sequentially transferred to the image receiving paper 6 to obtain a color image.

[0005]

However, such a conventional thermal printer has the following problems. That is, the image receiving paper 6 is placed on the platen roller 1
After being wound around 0, by heating from the back surface of the ink sheet 3 with the thermal head 2, yellow, magenta,
Cyan, black, and other dyes are sequentially transferred to an image receiving paper to obtain a color image. However, during this sequential transfer, a force acts so that the image receiving paper 6 wound around the platen roller 10 is displaced during movement,
For example, as shown in FIG. 3, there is a case where the sheet is skewed by the angle theta θ and a position shift occurs. As a result, the transfer position of each dye such as yellow, magenta, cyan, and black is deviated, which causes deterioration of a color image. For example,
In FIG. 3, even though the position of the image receiving paper at the time of the first dye transfer is a relatively fixed position indicated by A, the position of the image receiving paper at the time of the second dye transfer is at an angle theta as indicated by B. There is a problem in that the color image obtained is misaligned by θ and deteriorates.

Therefore, the present invention has been made in view of the above problems, and prevents the image receiving paper wound around the platen roller from being skewed and causing a positional shift, thereby preventing deterioration of the color image. The purpose is to do.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is designed such that an ink sheet on which dyes of a plurality of colors are applied surface-sequentially and an image-receiving paper are superposed on a platen roller and heated to heat the ink. In a thermal printer that prints a color image by transferring the dyes of the plurality of colors applied to a sheet to the image receiving paper in a frame-sequential manner, the image receiving paper positioning groove having the paper width is formed on the outer periphery of the platen roller. A characteristic thermal printer is provided.

Further, in order to solve the above problems, the present invention provides a thermal printer characterized in that the depth of the image receiving paper positioning groove is not more than the thickness of the image receiving paper. That is, the present invention, in order to solve the above problems, on the surface of a platen roller used in a thermal printer for recording by transferring the dye from the ink sheet to the image receiving paper by heating by superimposing the image receiving paper on the ink sheet. A paper width groove is provided for positioning the recording paper.

[0009]

As described above, according to the present invention, when the dyes are sequentially transferred to the image receiving paper, the image receiving paper is fitted into the groove of the platen roller, so that the image receiving paper is displaced from the image receiving paper. Even if the force is applied, the positional displacement of the image receiving paper does not occur, and the color image does not deteriorate.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will now be described in detail with reference to the accompanying drawings FIGS. 1 is a perspective view of a platen roller for winding an image receiving paper according to an embodiment of the present invention, and FIG. 2 is an explanatory diagram of a thermal printer incorporating the platen roller according to the embodiment of FIG. In FIG. 1, 1 is a platen roller according to the present invention, and 11 is a platen roller 1.
The guide groove is provided on the upper side and has the same width as the width of the image receiving paper for preventing the positional deviation of the image receiving paper wound for printing. It is desirable that the depth of the guide groove 11 be shallower than the thickness of the image receiving paper so that the pressing by the thermal head is not hindered. Further, when the image receiving papers having different widths are used, the platen rollers 1 having different widths of the guide grooves 11 can be exchanged.

In FIG. 2, 2 is a thermal head having a large number of heating elements arranged in a straight line and having a function of selectively heating the elements according to an input image signal, 3 is yellow, magenta, cyan, Sublimation type transfer ink sheet in which colors such as black are alternately arranged, 4 is a supply roll for sending out the ink sheet, 5 is a take-up roll for winding the ink sheet, and 6 is a receiving layer for receiving a dye transferred from the ink sheet Image receiving paper, 7 is a paper feed cassette accommodating the image receiving paper 6, which can be attached to and detached from a predetermined position of the printer main body, 8 is a paper feed roller for sending out the image receiving paper 6 in the paper feed cassette 7, and 9 is a print It is a paper discharge roller that discharges the received image receiving paper to the outside of the thermal printer.

Next, the operation of the thermal printer configured as described above will be described with reference to FIGS. 1 and 2. When the paper feed cassette 7 containing a large number of image receiving papers 6 stacked therein is set at the paper feed position shown in FIG. 2, the paper feed roller 8 operates to feed the uppermost image receiving paper 6 and wind it around the platen roller 1. . At this time, the image receiving paper 6 is wound in the paper width guide groove 11 provided on the platen roller 1. Since the image receiving paper 6 moves along the guide groove 11 on the platen roller 1, even if a force that causes a positional deviation such that the image receiving paper 6 is skewed in the theta θ direction is applied during the movement, the guide groove 11 is formed. The positional deviation is prevented by this, and the image receiving paper 6 moves without causing positional deviation. Therefore, when the dyes are sequentially transferred to the image receiving paper 6, the positional deviation in the theta θ direction does not occur, so that the deterioration of the color image does not occur.

The image receiving paper 6 on which the yellow, magenta, cyan and black colors of the ink sheet 3 are color printed by the selective heat generation of the thermal head 2.
Is discharged to the outside of the thermal printer by the paper discharge roller 9. In this embodiment, the image receiving paper is wound around the platen roller to transfer the dye, but the present invention is not limited to this method, and for example, the platen roller and the paper feeding / discharging roller hold the image receiving paper to transfer the dye. Also in the transfer method, the platen roller is provided with a guide groove having the width of the paper, so that the positional deviation of the image receiving paper is prevented and a high quality color image can be obtained.

[0014]

As described above, in the thermal printer according to the present invention, the platen roller around which the image receiving paper is wound is provided with the guide groove having the width of the paper, so that the force of causing the positional deviation of the image receiving paper is exerted. Even in this case, the guide groove can prevent the positional deviation, and the dye can surely move from the ink sheet to the intended position on the image receiving paper to form a high quality image.

[Brief description of drawings]

FIG. 1 is a perspective view of a platen roller according to an embodiment of the present invention.

FIG. 2 is an explanatory view of a thermal printer having a platen roller according to the embodiment of FIG.

FIG. 3 is a perspective view of a platen roller of a conventional thermal printer.

[Explanation of symbols]

 1, 10: Platen roller 2: Thermal head 3: Ink sheet 4: Paper feeding roll 5: Take-up roll 6: Image receiving paper 7: Paper feeding cassette 8: Paper feeding roller 9: Paper discharging roller 11: Guide groove

Claims (2)

[Claims] 1. An ink sheet on which a plurality of color dyes are applied in a frame-sequential manner and an image-receiving paper are superposed on a platen roller and heated so that the dyes of a plurality of colors applied to the ink sheet are surface-sequentially. A thermal printer that prints a color image by shifting to the image receiving paper, characterized in that an image receiving paper positioning groove having a paper width is formed on the outer periphery of the platen roller. 2. The thermal printer according to claim 1, wherein the depth of the image receiving paper positioning groove is less than or equal to the thickness of the image receiving paper.