JPH02239984A - Thermal transfer recording - Google Patents

Abstract

PURPOSE:To obtain a natural color image by stably superposing respective color images one upon another by performing the thermal transfer recording of the image corresponding to a color low in transfer temp. and subsequently performing the thermal transfer recording of the image corresponding to a color high in transfer temp. so as to be superposed on the transfer image of said one color. CONSTITUTION:Respective color printing parts 2Y, 2M, 2C of yellow (Y), magenta (M) and cyan (C) are successively arranged along the feed direction of printing paper 1 and, at the time of printing operation, thermal heads 5Y, 5M, 5C are allowed to fall and respective transfer films 3Y, 3M, 3C and the printing paper 1 are closely adhered in a superposed state in the printing parts between said heads and platen drums 6Y, 6M, 6C. At first, the thermal transfer recording of the image corresponding to the color Y lowest in transfer temp. is performed and, next, that of the image corresponding to the color M slightly high in transfer temp. is performed and, at last, that of the image corresponding to the color C highest in transfer temp. is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Fields] The present invention relates to a thermal transfer recording system in which a transfer film of each color is heated by a thermal head, and images corresponding to each color are sequentially superimposed to perform thermal transfer recording. Regarding the method.

[Prior Art] In various color image printing devices such as thermal transfer color printers and thermal transfer color copying machines, each color transfer film coated with heat sublimation or heat melt ink is applied to printing paper. The images are overlapped and heated by a thermal head that generates a heat pattern according to the image recording information.
Thermal transfer recording is performed by selectively transferring the ink in the transfer film for each color. At this time, images corresponding to each color are sequentially superimposed to obtain a final image.

[Problems to be Solved by the Invention] However, in the general thermal transfer recording method, the ink of each superimposed French image does not adhere well to the paper as described above, resulting in a lack of image stability. In addition, the colors of the transferred images are often not mixed well, resulting in unnatural color images.

In order to solve these problems, various thermal transfer recording methods have been proposed. For example, JP-A-60-125
In the thermal transfer recording method described in Publication No. 696, transfer films of different colors with different transfer temperatures are prepared, first, an image corresponding to a color with a higher transfer temperature is thermally transfer recorded, and then an image is superimposed on the transferred image of one color. Thermal transfer recording of the image corresponding to the color with a lower transfer temperature is performed in such a manner that the image corresponding to each color is thermally transferred recorded. Also, JP-A-62-46661
In the thermal transfer recording method described in the publication, the permeability of ink is improved by increasing the temperature of printing paper. Furthermore, in the thermal transfer recording method described in Japanese Utility Model Application Publication No. 63-128035, the ink permeability is improved by reheating the printing paper after printing.

However, none of these proposed methods has yet achieved superposition transfer with sufficient image stability and image color development.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a thermal transfer recording method that allows images of each color to be stably superimposed and also allows a natural color image to be obtained.

[Means for Solving the Problems] In order to achieve the above object, the invention described in claim 1 heats each color transfer film having a different transfer temperature using a thermal head, and sequentially overlays images corresponding to each color. In a thermal transfer recording method in which thermal transfer recording is performed by aligning the transfer temperature, first thermal transfer recording is performed of an image corresponding to a color with a low transfer temperature, and then the transfer temperature is It has a configuration that allows thermal transfer recording of images corresponding to high colors.

Further, in the invention described in claim 2, each color transfer film is heated by a thermal head whose heating capacity is variably controlled, and thermal transfer recording is performed by sequentially overlapping images corresponding to each color. In the thermal transfer recording method, first, a thermal head whose heating capacity is controlled to a low state performs thermal transfer recording of an image corresponding to a color with a low transfer temperature, and then the heating capacity is increased so that it is superimposed on the transferred image of that one color. It has a configuration in which thermal transfer recording of an image corresponding to a color having a high transfer temperature is performed by the thermal head 1 controlled to a high state.

Furthermore, the invention described in claim 3 is a thermal transfer recording system in which a thermal head heats each color transfer film having a different transfer temperature, and thermal transfer recording is performed by sequentially overlapping images corresponding to each color. In this method, thermal transfer recording is performed by sequentially overlapping images corresponding to each color, and then the entire overlapping transferred images are reheated at a temperature higher than the thermal transfer temperature of the image corresponding to the final color. It has the following configuration.

[Function] In the means having the configuration described in claim 1,
When a transfer image corresponding to a color with a high transfer temperature is superimposed on a transfer image corresponding to a color with a low transfer temperature,
The transferred image corresponding to the previously transferred color with a lower transfer temperature is reheated and remelted or resublimated, which improves the adhesion between the ink and the paper or causes the ink to bond with the paper binder. As it progresses toward the back, color mixing of the transferred images of each color occurs in the dye, and color mixing is promoted.

Further, in the means having the structure described in claim 2, the heating effect of the thermal head whose heating capacity is controlled to be low is applied to the transferred image of the color having a low transfer temperature that has already been transferred. Due to the heating effect of the thermal head, which is controlled to a high capacity state, transferred images corresponding to colors with high transfer temperatures are superimposed,
The same effect as that corresponding to the means of claim 1 above can be obtained.

Furthermore, in the means having the structure set forth in claim 3, in addition to the action corresponding to the means of claim 1,
By reheating at a temperature above the transfer temperature of the final image,
The entire transferred image is remelted or resublimated, which further improves the adhesion between the ink and the paper, or allows the ink to penetrate deeper into the paper binder.
Color mixing of the transferred images of each color occurs further in the dye, further promoting color mixing.

[Example] Hereinafter, an example of the present invention will be described in detail based on the drawings.

First, FIG. 1 shows an outline of the printing press operating section of a thermal transfer type color printer as an example of a color image printing apparatus for carrying out the present invention.

In Figure 1, yellow (Y), 18 for printing paper 1
- magenta (M), cyan (C) color printing section 2Y,
2M, 2C. are arranged in order along the feeding direction of the printing paper 1. The color transfer films 3Y, 3M, and 3C used in the color printing sections 2Y, 2M, and 2C are as follows:
The sheets are pulled out from the sheet feed rolls 4Y, 4M, 4-C, and inserted into the respective printing sections between the thermal heads 5Y, 5M, 5C and the platen drums 6Y, 6M, 6C. Each of the above color transfer films 3Y, 3
M, 3C are further pulled out from the printing section, and sheet winding rolls 7Y, 7M are used as transfer film pulling means.
, 7C.

When the printing operation is performed, the thermal heads 5Y, 5
M, 5C are lowered and thermal heads 5Y, 5M, 5C
In the printing section between the and platen drums 6Y, 6M, 6C,
Each color transfer film 3Y, 3M, 3C and the printing paper 1 are superimposed and brought into close contact with each other. Each of the thermal heads 5Y, 5M, and 5C has a function of generating a thermal pattern according to the image recording information, and the heat generation effect of the thermal heads 5Y, 5M, and 5C creates a heat pattern in each color transfer film 3Y, 3M, and 3C. The ink is selectively transferred onto the printing surface of the printing paper 1 to perform printing and recording operations.

At this time, the platen drums 6Y, 6M, 6C, the color transfer films 3Y, 3M, 3C, and the printing paper 1 are as follows:
Printing is performed while being transferred in synchronization with the cycle of one line of image data sent to the thermal heads 5Y, 5M, and 5C.
An image corresponding to the Y color is transferred onto the printing paper 1 by the Y, and then an image corresponding to the M color is transferred and formed by the thermal head 5M so as to be superimposed on the Y color transferred image, and finally the thermal An image corresponding to C color is transferred and formed by the head 5c so as to be superimposed on the Y color transfer image and the M color transfer image to obtain a final color image.

Further, the color transfer films 3Y, 3M, and 3C are formed to have different transfer temperatures, and the required transfer temperature of the Y color transfer film 3Y is 150°M color transfer film 3.
The required transfer temperature for M is set at 18,000, and the required transfer temperature for color transfer film 3C is set at 200°. The required transfer temperature for each color transfer film 3Y, 3M, and 3C can be determined by changing the base thickness of each color transfer film, changing the mixing ratio of wax contained in the ink, or changing the mixing ratio of ink and binder. It is adjusted by

Furthermore, the aforementioned thermal control heads 5Y, 5M, and 5G are configured such that the heating capacity is variably controlled, and means for adjusting the heating capacity includes means for adjusting the applied pulse width, means for adjusting the number of applied pulses, There are means for adjusting the applied voltage. And these thermal heads 5Y, 5M,
5G, the heating power is controlled according to the required transfer temperature of each color transfer film 3Y, 3M, 3G.

In one embodiment of the present invention using such a thermal transfer type color printer, first, thermal transfer recording of an image corresponding to the color Y, which has the lowest transfer temperature, is performed, and the image is superimposed on the transferred image of the Y color. Thermal transfer recording of an image corresponding to M color, which has a slightly higher transfer temperature, is performed, and finally the above Y
Thermal transfer recording of an image corresponding to C color, which has the highest transfer temperature, is performed so as to be superimposed on the color transfer image and the M color transfer image.

In the thermal transfer recording method in such an embodiment,
First, when the transferred image corresponding to the M color, which has a slightly higher transfer temperature, is superimposed on the transferred image corresponding to the Y color, which has the lowest transfer temperature,
The transferred image corresponding to the color is reheated and remelted or resublimated, which improves the adhesion between the ink and the paper, or allows the ink to penetrate deeper into the paper binder, causing both colors to be reheated and remelted or sublimated. Color mixing of the transferred image occurs in the dye, thereby promoting color mixing. Furthermore, when an image corresponding to C color, which has the highest transfer temperature, is superimposed on these two-color transfer images, the two-color transfer image that has been transferred first is reheated and remelted or resublimated. As a result, the adhesion between the ink and the paper is further improved, or the ink moves deeper into the paper binder, and color mixing of the three-color transferred image occurs in the dye, further promoting color mixing. It is now possible to

In another embodiment of the present invention using the above-mentioned thermal transfer type color printer, first, as in the above-mentioned embodiment, thermal transfer recording of an image corresponding to the Y color having the lowest transfer temperature is performed; Thermal transfer recording of an image corresponding to the color M, which has a slightly higher transfer temperature, is performed so as to overlap the transferred image, and the image corresponding to the color M, which has the highest transfer temperature, is further superimposed on the transferred image of the Y color and the transferred image of the M color. Thermal transfer recording of an image corresponding to C color is performed. After thermal transfer recording of the image corresponding to the final C color is performed, the entire superimposed transfer image that has already been transferred is reheated at a temperature higher than the thermal transfer temperature of the C color transfer image. It has become. Such reheating of the entire image may be performed using a thermal head, or may be performed using a heating means other than the thermal head, such as a heating roller.

According to such an embodiment, it is possible to further improve the adhesion between the ink and the paper, and further promote color mixing in the transferred image.

In the thermal transfer color printer shown in FIG. 2(a), the transfer film 30 is formed from a long strip, and as shown in FIG. 2(b), one screen is printed. A fixed printing area is arranged in parallel so as to be continuous for a large number of screens. The transfer film 3o in this device is a three-color transfer film, and the color printing areas of yellow (Y), magenta (M), and cyan (C) are arranged in order in the longitudinal direction of the transfer film 30. ing.

During printing, the transfer film 30 is first located, and the printing and recording operation is performed while each screen area of the fixed printing areas Y, M, and C of the transfer film 30 is sent out in sequence. . In addition, in the case of a transfer film that can be used repeatedly multiple times, each time a printing operation is performed, a sheet feed roll (not shown) is reversed, the transfer film is rewound to the original printing start position, and the printing operation is The fixed printing areas Y, M, and C of the transfer film returned to the copying start position are fed out in sequence again and a second printing/recording operation is performed, and thereafter, a plurality of similar printing/recording operations are performed. It is designed to be repeated N times. The same thermal transfer recording method as in the above embodiment can be applied to each of these devices. Further, as described above, the long strip-shaped transfer film 3 is arranged in parallel so that a fixed printing area for printing one screen is continuous for many screens.
It is also possible to have one thermal head perform printing for 0.

In each of the above-mentioned embodiments, the amount of transfer film used can be saved by setting the printing paper feed speed to 1/n or less relative to the transfer film feed speed. Further, the order in which the transferred images are superimposed is preferably such that the hue does not change.

When superimposing the colors in the order of Y, M, and C as in each of the above embodiments, hue stability is obtained and good brightness is obtained.

[Effect of the invention] As stated above, the invention stated in claim 1 has the following effects:
In order to improve the adhesion of the ink by reheating and remelting or resublimating the previously transferred image, and to promote the color mixing of each color image, the image corresponding to the color with a lower transfer temperature is first transferred. Since thermal transfer recording is carried out, and an image corresponding to a color having a high transfer temperature is superimposed on the transferred image of one color, the stability of the superimposed transferred image can be improved. , it is possible to obtain an image with natural color development.

Further, the invention described in claim 2 is such that the previously transferred image is reheated and remelted or resublimated to improve the adhesion of the ink and to promote color mixing of each color image. First, an image corresponding to a color with a low transfer temperature is thermally transferred recorded using a thermal head whose heating capacity is controlled to be in a low state, and then the heating capacity is controlled to be in a high state so as to be superimposed on the transferred image of that one color. Since the image corresponding to the color having a high transfer temperature is thermally transferred and recorded by the thermal head that is attached to the image forming apparatus, the stability of the superimposed transferred images is improved, similar to the effect of the means corresponding to claim 1 above. In addition, it is possible to obtain an image with natural color development.

Furthermore, the invention described in claim 3 further improves the adhesion of the ink by reheating and remelting or resublimating the transferred image after being transferred, in addition to the means of claim 1, In order to further promote the color mixing of each color image, reheating is performed at a temperature higher than the transfer temperature that is applied after the final image is transferred, making it possible to further improve the stability of the superimposed transferred images. At the same time, an image with more natural color development can be obtained.

[Brief explanation of drawings]

FIG. 1 is an explanatory side view showing an example of a thermal transfer printer to which the thermal transfer recording method of the present invention is applied, and FIGS. FIG. 7 is an explanatory side view and a plan view showing another thermal transfer printer and transfer films of each color. 1...Print paper, 2Y, 2M, 2G...color printing section, 3Y, 3M, 3C, 30...each color transfer film, 5
Y, 5M, 5C...Thermal head, 6Y, 6M, 6
C...Platen drum. (1 other person)

Claims (1)

[Claims] 1. In a thermal transfer recording method in which transfer films of different colors having different transfer temperatures are heated by a thermal head and images corresponding to each color are sequentially superimposed to perform thermal transfer recording, first, the transfer is performed. A thermal transfer recording method characterized in that an image corresponding to a color with a low temperature is thermally transfer recorded, and an image corresponding to a color with a high transfer temperature is thermally transfer recorded so as to be superimposed on the transferred image. 2. In a thermal transfer recording method in which thermal transfer recording is performed by heating each color transfer film using a thermal head whose heating capacity is variably controlled and sequentially overlapping images corresponding to each color, first, the heating capacity is low. A thermal head whose heating capacity is controlled to thermally transfer an image corresponding to a color with a low transfer temperature is recorded, and a thermal head whose heating capacity is controlled to a high state records a color with a high transfer temperature so as to be superimposed on the transferred image. 1. A thermal transfer recording method, characterized in that thermal transfer recording of an image corresponding to the above is performed. 3. In a thermal transfer recording method in which transfer films of different colors with different transfer temperatures are heated by a thermal head and images corresponding to each color are sequentially superimposed to perform thermal transfer recording, first, colors with lower transfer temperatures are handled. After performing thermal transfer recording of an image corresponding to a color with a high transfer temperature so as to be superimposed on the transferred image, the entire superimposed transferred image is made to correspond to the final color. A thermal transfer recording method characterized by reheating at a temperature higher than the thermal transfer temperature of the image.