JPH0455870B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermal transfer printing method using a sublimation dye, and in particular, to ensure color development of the sublimation dye to produce clear printing.

In still cameras and the like that record image information on a magnetic sheet or the like, it is required to obtain a hard copy from the image signal. In such a case, a printing method using sublimation dye may be considered, and a printer as shown in FIG. 1 may be used.

In FIG. 1, this printer consists of a platen 1, a thermal head 2, etc. Platen 1
is for winding the transfer paper 3, and is fed in steps in the direction shown by arrow a. The transfer paper 3 is made of, for example, high-quality paper, and a polymer resin layer of 1 to 2 μm is formed on the transfer side as necessary. This polymer resin layer is for promoting the diffusion coloring of the sublimation dye.

The ribbon 4 is stored in, for example, a cartridge (not shown) and loaded into a printer. This ribbon 4
is made by printing sublimation dye for transfer onto capacitor paper. Specifically, frames 4Y, 4M, and 4C are coated with yellow, magenta, and cyan dyes, respectively.
is formed repeatedly. This frame 4Y, 4
M and 4C correspond to video rasters. Of course, the sublimation dye is printed on the receiving paper 3.

The thermal head 2 thermally transfers the sublimation dye from the ribbon 4 onto the transfer paper 3. The thermal head 2 is composed of a large number of head elements 2a, and these head elements 2a are driven by pulses. That is, video signals, specifically yellow, magenta and cyan chromaticity signals, are pulse width modulated and supplied to each head element 2a. The larger the amplitude of the chromaticity signal, the longer the driving time of the head element 2a becomes, and the larger the amount of sublimation dye transferred.

In a printing method using such a printer, the ribbon 4 is pressed against the transfer paper 3, and the ribbon 4 is step-fed together with the transfer paper 3. First, the yellow frame 4Y of the ribbon 4 is brought into close contact with the transfer paper 3. At this time, thermal head 2
A drive signal corresponding to the yellow chromaticity signal is supplied to the yellow chromaticity signal. When the transfer of the yellow component for one line of the raster is completed, the platen 1 is driven by one step to prepare for the transfer of the next line. The entire raster is transferred in the same manner.

A similar operation is performed for the magenta and cyan frames 4M and 4C, and the magenta transfer image is superimposed on the yellow transfer image, and the cyan transfer image is further superimposed. Finally, a color image is obtained on the transfer paper 3.

In FIG. 1, 4a is a mark for frame detection, and 4b is a mark for detecting a block consisting of three frames. These marks 4a and 4b are detected by photo sensors 5a and 5b, respectively, to synchronize each frame and each block.

By the way, in such a printing method, it is known that the image becomes clearer when the transfer paper 3 after transfer is reheated using a heat roller or the like. Due to the method in which the amount of transfer is controlled by the amount of heating, that is, the width of the driving pulse of the head element 2a, it is difficult to apply enough heat to the transfer paper 3 to diffuse the dye, and the subsequent reheating promotes the diffusion. be.

On average, without reheating, about 80% of the dye is only diffused, and the remaining 20% is only attached, and color development is inhibited by this 20%. has been done. It promotes this 20% diffusion and color development.

However, such reheating requires an extra step and also requires a heating roller or the like.

The present invention has been made in consideration of these circumstances, and it is an object of the present invention to provide a thermal transfer printing method that can easily reheat the transferred paper.

Hereinafter, an embodiment of the thermal transfer printing method according to the present invention will be described with reference to FIGS. 2 and 3.

FIG. 2 shows the ribbon 11 used in this example, and in this figure, the ribbon 11 is made by printing sublimation dye on capacitor paper, similar to that in FIG. 1 frame each for yellow, magenta and cyan
1Y, 11M, and 11C are also similar to those shown in FIG. In this example, such frames 11Y, 11
In addition to M and 11C, there is a black frame 1 that forms the finishing version.
Along with forming 1Bk, this black frame 1
A space 11a for one frame is formed between 1Bk and the yellow frame 11Y. No sublimation dye is printed in this space 11a.

In addition, in this ribbon 11, the width is 104 mm, the length of the block is 750 mm, and the frames 11Y, 11M,
The size of both 11C and 11Bk is 145mm x 86mm.

FIG. 3 shows a printer used in the printing method of this example, and the same reference numerals as those in FIG. 1 are used. In this example, the frames 11Y, 11M of the ribbon 11,
11C and 11Bk, a pulse signal corresponding to the image signal is supplied to the thermal head 2. As a result, an image is formed on the transfer paper 3. Note that a pulse signal corresponding to the luminance signal is supplied to the thermal head 2 in correspondence with the black frame 11Bk, thereby making it possible to supplement the gradation. On the other hand, direct current is supplied to the thermal head 2 corresponding to the space 11a. In this case, the entire raster corresponding area of the transfer paper 3 is heated by the thermal head 2 via the space 11a of the ribbon 11.
By this heating, the sublimation dye, which had been merely attached, diffuses and develops a sufficient color.

Note that instead of supplying direct current to the thermal head 2 corresponding to the space 11a, a pulse signal capable of heating the entire raster corresponding area may be supplied to the thermal head 2. For example, it is a pulse signal that is low level at the step feed timing and high level at other timings. however,
In order to extend the life of the thermal head 2, it is preferable to use direct current. In addition, in order to prevent insufficient heating in the area that is heated in advance due to the heat capacity of the thermal head 2, it is preferable to increase the current level in the inrush portion where the direct current starts to be supplied. . In this way, the entire area of the raster can be heated uniformly and the image can be equally sharp.

As described above, according to the thermal transfer printing method of the present invention, a space 11a to which no sublimation dye is applied is formed in the ribbon 11, and the transfer paper can be reheated through this space 11a.
Therefore, a reheating step can be included in one transfer cycle without any complications. Furthermore, the fixing properties of the transferred dye can be significantly improved without requiring a separate dedicated device for reheating.

Note that the present invention is not limited to the above-mentioned embodiments, and various modifications can be made. For example, in the example described in FIGS. 2 and 3, the thermal head 2
was used for reheating. In this way, we were able to avoid increasing the number of parts. However, if the life of the thermal head 2 is to be extended, it is preferable to use a heating roller 12 separately from the thermal head 2. That is, frame 11Y,
When performing transfer corresponding to spaces 11M, 11C, and 11Bk, the heating roller 12 is retracted to the position shown by the broken line, and when performing reheating corresponding to the space 11a, the heating roller 12 is moved so that the platen 1 The crocodile is crimped. In addition, in FIG. 4, parts corresponding to those in FIG. 3 are given corresponding symbols, and respective explanations are omitted.

[Brief explanation of the drawing]

FIG. 1 is a perspective view for explaining the present invention, FIG. 2 is a plan view showing a ribbon 11 used in an embodiment of the thermal transfer printing method according to the present invention, and FIG. 3 is an embodiment of the printer according to the present invention. FIG. 4 is a schematic side view showing a modification of the example in FIG. 3. 1 is a platen, 2 is a thermal head, 3 is a transfer paper, 11 is a ribbon, 11Y, 11M, 11C,
11Bk is a frame coated with yellow, magenta, cyan, and black sublimation dyes, and 11a is a space to which no sublimation dye is coated.

Claims (1)

[Claims] 1. A thermal head is pressed onto a transfer paper with a transfer area coated with a sublimation dye of the transfer paper interposed therebetween,
a first step of thermally transferring the image onto the transfer paper by applying heat according to the image information using the thermal head; and a first step of thermally transferring the image onto the transfer paper by applying heat according to the image information; A thermal transfer printing method, comprising: a second step of press-bonding the transferred paper to paper and reheating the transferred portion of the transferred paper using the heating means. 2. The non-transfer area has an area equivalent to at least one screen, and the heating means reheats the transferred screen while bringing the non-transfer area into close contact with the transferred screen of the transfer paper. A thermal transfer printing method according to claim 1. 3. Claim 1, wherein the thermal head is also used as the heating means.
The thermal transfer printing method according to item 1 or 2.