JPH09156239A - Thermal transfer recording method and apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To repeatedly form a stable image free from density irregularity by superposing a transfer film obtained by adding a sublimable dye to the through-holes of a film having a large number of through-holes and an image receiving material one upon another and imagewise heating them to form an image on the image receiving material. SOLUTION: A porous transfer film 3 obtained by adding a sublimable dye to the holes of a porous base material film or to the resin in the holes by a sublimable dye supply means 1 and an image receiving material 5 are superposed one upon another and heated on the side of the transfer film 3 by the heat source of a recording heat 4 such as a thermal heat or laser and the sublimable dye in the transfer film is diffused through the holes of the transfer film 3 to form an image on the image receiving material 5 to complete transfer. Thereafter, the transfer film 3 is regenerated by supplying the sublimable dye in the holes of the film or in the resin of the holes by the sublimable dye supply means. By this constitution, a stable image free from density irregularity can be repeatedly formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer recording method and recording apparatus used in a copying machine, a printer, a fax machine and the like.

[0002]

2. Description of the Related Art A sublimation type thermal transfer recording method has been applied to a full color printer and is beginning to spread in the market because it is excellent in gradation and color reproducibility and an image similar to a silver salt color photograph can be obtained. However, since the utilization efficiency of the ribbon holding the dye is low, the price thereof becomes a problem, and the utilization efficiency is being studied. For example, attempts have been made to increase the repetition characteristics of the ink ribbon by changing the layer structure of the sublimation dyeing layer, but this has been limited to several times. In addition, another method has been proposed in which the relative speed between the image receiving member and the ink ribbon is changed so that the speed of the ink ribbon is reduced to form an image, and the utilization efficiency of the ink ribbon is increased. However, the utilization efficiency has been increased only 15 to 20 times. Therefore, Japanese Patent Application Laid-Open
In −55852, the sublimation dye can be continuously supplied to the heat-sensitive transfer recording medium from the outside so that it can be repeatedly used many times. However, this method does not sufficiently supply the sublimation dye, and it has been known that density unevenness easily occurs during repeated use.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to develop a thermal transfer recording method and recording apparatus which solve the following problems. 1. The sublimation dye is sufficiently supplied so that a stable image having no density unevenness can be repeatedly formed. 2. An image with high density and good gradation is stably formed. 3. A stable supply of sublimation dye to maintain high image quality is realized. 4. Ensure sublimation dye supply. 5. It assists the diffusion of sublimation dye and ensures the supply of sublimation dye. 6. Realizes stable and repeated use of transfer film. 7. The system is simple, and fine pixels can be formed at high speed.

[0004]

The present invention is characterized in that a transfer film in which at least a dye is contained in the pores of a porous film and an image receptor are superposed on each other and are imagewise heated to form an image on the image receptor. The present invention relates to a thermal transfer recording method. In the present invention, as shown in FIG. 1, a sublimation dye supply means 1 is used to form a porous transfer film 3 containing a sublimation dye in the pores of a porous substrate film or a resin of the pores, and an image receptor 5. In the superposed state, the transfer film 3 side is heated by the heat source of the recording head 4 such as a thermal head or a laser, and the sublimation dye in the transfer film 3 diffuses through the holes in the transfer film 3 to form an image on the image receiver 5. After being formed and after the transfer is completed, the transfer film 3 is regenerated by supplying the sublimation dye into the holes of the film or the resin of the holes by the sublimation dye supply means. In the present invention, the image to be transferred may be not only a graphic image but also a character. The base film of the transfer film 3 is made of a heat resistant plastic film such as polyethylene terephthalate, polyether sulfone, polyphenylene sulfide, polyether ether ketone, or polyimide, and has a large number of through holes. The through hole can be opened by laser processing or the like. If the pore size is too small, the image density will be too low, and if it is too large, the image will be very standing, so 0.1 to 100 μm, preferably 1 to 3 μm.
0 μm. Further, the thickness of the base film affects not only the image density but also the recording sensitivity and the durability, and if the film thickness is too thin, the image becomes a stand-up image and the film is easily deformed by heat, resulting in poor durability. The thicker the film, the lower the image density and the recording sensitivity. Therefore, the thickness is 1 to 200 μm, preferably 1 to 30 μm.
The resin to be contained in the pores of the film together with the sublimation dye may be filled with a resin having an appropriate compatibility with the sublimation dye and having a good diffusibility of the sublimation dye. As such resin,
For example, polyvinyl alcohol, polypropylene, polystyrene, polyester, polyvinyl chloride, polycarbonate, cellulose esters, silicone resins, dimethyl silicone resins, methylphenyl silicone resins, block copolymers of crosslinked silicone and organic resins such as polyester and polyvinyl chloride. Coalescence or the like is used. Among the above resins, polyvinyl alcohol, polypropylene, polystyrene, polyester, polyvinyl chloride, silicone resin, dimethyl silicone resin, methylphenyl silicone resin and the like are particularly preferable. When the resin as described above is put into the holes, there is an advantage that the gradation is improved.

The sublimation dye is supplied into the holes of the transfer film 3 or into the resin of the holes by supplying the powder sublimation dye from a sublimation dye supply means such as a roller with a hopper by electrostatic attraction. A uniform coating film is formed or it is diffused in the resin by a heating means. In addition, after charging the transfer film with a corona charger, a powder sublimation dye is supplied from a sublimation dye supply means such as a roller with a hopper, and a blade and a heating means are used to form a uniform coating film and uniformly diffuse the liquid sublimation dye. There is a method of coating with a sponge roller or a rubber roller and diffusing and curing with a heating means. When a sublimation dye is supplied into the pores, heat treatment with a heating means such as a heater at the time of coating improves the adhesiveness to the film, which is effective. The sublimation dye supply means 1 may be provided on the front side (image receptor side) or the back side of the transfer film.
In FIG. 1, a sublimation dye coating means (sublimation dye coating roller) 1
1. A thin dye is coated on the back side of the transfer film 3 by 1, and then the dye is diffused into the hole or the resin of the hole using the heating means (heating roller) 2, and finally remains on the back side of the transfer film 3. A sublimation dye supply means 1 for scraping off the dye with a blade 12 is shown. The temperature of the heating roller 2 varies depending on the sublimation dye, but 60 to 200 ° C. is suitable. If the dye remains on the back side of the transfer film, the recording head becomes dirty, so cleaning with a blade must be performed reliably. When cleaning is insufficient, a separate cleaning means must be provided. Further, the holes of the transfer film 3 may be tapered in the thickness direction, and the sizes of the hole diameters of one surface and the other surface are appropriately determined according to the γ characteristic (recording energy image density characteristic) of the process. However, for example, in order to prevent re-diffusion to the recording head 4, the hole shape of the transfer film is tapered,
It is also effective to make the hole diameter small on the recording head side and large on the image receptor side. As shown in FIG. 1, when an image is formed, only the transfer film 3 and the image receiver 5 are sandwiched by the recording head 4 and the platen roller 6 which are heat sources, so that the recording sensitivity is improved. The transfer film is preferably formed into an endless belt shape as shown in FIG. 1. By forming the transfer film into an endless belt shape, the transfer film is rotated and repeatedly reproduced for use. When forming an image, the finer each pixel is, the higher the image quality becomes. Therefore, the thermal head and the laser are suitable as the image forming heat source of the recording head 4.

Examples of sublimation dyes include disperse dyes, disperse anthraquinone dyes, disperse monoazo dyes, oil-soluble dyes, cationic dyes, nitro dyes, leuco dyes, quinophthalone dyes, naphthalocyanine dyes, tricyanostil dyes and oil-solubilized cationic dyes. To use. Further, as an inorganic type, carbon black, Sn, Sb, Pb, Bi, As,
Those containing Zn, Cd, In, Au, Al, Cu, Te, etc., or oxides thereof, and as organic type, polymethine type dye, azulene type dye, naphthoquinone type dye, pyrylium type dye, phthalocyanine type dye, naphthalocyanine Dyes, cyanine dyes, fluorene dyes, rhodamine dyes, triarylamine dyes, aminium dyes, diimonium dyes, central metals being Ni, Pd, C
A chelate compound such as u or Co may also be used. When forming a full-color image, a yellow image forming section 10, a magenta image forming section 8 and a cyan image are formed around a large platen roller 9 as shown in FIG. The forming part 7 is provided,
This is done by forming each color on the image receptor. However, the device configuration is not limited to this, and for example, a configuration in which the image forming units are arranged side by side may be used.

Example 1 Image formation was carried out by using an apparatus having a structure as shown in FIG. 1 and changes in image density were examined. Powdered magenta dye (Mitsui Toatsu Co., Ltd .: dye sublimation dye MS Magenta
VP) is placed in a hopper of a sublimation dye coating means composed of a rubber roller and a blade having a rough surface, and the back side of a seamless endless belt-shaped transfer film 3 made of a porous polyimide film (10 μm thick) (not in contact with an image receiver). Thinly and evenly applied on the surface) and then heated by the heating means (heat roller) 2 to diffuse into the resin in the pores, and thereafter unnecessary sublimation dye was removed by a blade. In the transfer film, a polyimide film (10 μm thick) having heat resistance is preliminarily formed with a large number of uniform through holes by a laser in advance, and polyvinyl butyral resin (manufactured by Sekisui Chemical Co., Ltd .: It is used by impregnating BX-1). In this embodiment, the laser output is changed to change the hole diameters to 1, 5, 10, 1
A transfer film having a thickness of 5 μm was prepared, and the relationship with the image density when an image was formed using them was investigated. The image density was examined with a Macbeth densitometer. A thermal head was used as the recording head 4, and the recording energy was 30 mJ / mm ² . As the image receiver 5, photographic paper having an image receiving layer made of polyvinyl butyral was used. The image formation was repeated 20 times, and the 20th image density was used as data. As a result, the results are as shown in Table 1 and FIG. 3 below, and it was found that there was no density decrease even when repeated in the experimental range of this time, and sufficient image formation was performed. The image density increased as the pore size increased and the amount of sublimation dye transfer increased.

[Table 1]

Example 2 Image formation was carried out under the same conditions except that the transfer film 3 was not impregnated with resin in the transfer film 3 using a high power semiconductor laser (λ = 780 nm) in the recording head portion of FIG. The light spot diameter was about 3 μm, and the light output on the sublimation dye supply film was about 30 mW. This time, the film thickness of the transfer film 3 was changed to 5, 10, 15, and 20 μm (the hole diameter of the transfer film was fixed at 5 μm), and an image forming experiment was conducted to examine the relationship with the image density. The image formation was repeated 20 times, and the 20th image density was used as data. as a result,
The results are shown in Table 2 and Figure 4 below.
It was found that the image was sufficiently formed without repeating the density reduction even if it was repeated 0 times. Regarding the image density, as the film thickness increased, the heat transfer deteriorated, and the image density decreased.

[Table 2]

The embodiments of the present invention will be described below. 1. A heat-sensitive transfer recording method characterized by forming an image on an image receptor by heating imagewise in a state where a transfer film made by containing at least a sublimation dye in a through hole of a porous film and an image receptor are superposed on each other. . 2. A heat-sensitive transfer recording method, characterized in that a sublimation dye is contained in a porous film to prepare a transfer film, and the transfer film and the image receptor are heated in a superposed state to form an image on the surface of the image receptor. 3. The above-mentioned 1 in which the resin having compatibility with the sublimation dye and good diffusibility of the sublimation dye is filled in the through hole of the transfer film.
2 to 2. The thermal transfer recording method. 4. 4. The heat-sensitive transfer recording method as described in 1 to 3 above, wherein the base film of the transfer film is a heat resistant plastic film. 5. The thermal transfer recording method of 1 to 4 above, wherein the transfer film has a pore size of 0.1 to 100 μm, preferably 1 to 30 μm, and a thickness of 1 to 200 μm, preferably 1 to 30 μm.

[0010] 6. 6. The heat-sensitive transfer recording method described in 1 to 5, wherein the through-holes of the transfer film are tapered in the thickness direction, and the hole diameter of one surface is different from the hole diameter of the other surface. 7. 7. The thermal transfer recording method according to 1 to 6, wherein the through-hole has a small diameter on the recording head side and a large diameter on the image receiving side. 8. 8. The thermal transfer recording method as described in 1 to 7 above, wherein the transfer film is heat-treated after forming the sublimation dye layer. 9. 9. The thermal transfer recording method as described in 8 above, wherein the heat treatment is performed at 60 to 200 ° C. 10. 1 to 9 in which the heat treatment is performed from the transfer film side
Thermal transfer recording method. 11. 11. The thermal transfer recording method described in 1 to 10 above, wherein the transfer film is in the form of an endless belt. 12. 12. The thermal transfer recording method described in 1 to 11 above, wherein a thermal head or a laser is used as a transfer heating source.

13. A porous film (A) having a large number of through holes, a means (B) for producing a transfer film by including a sublimation dye in the through holes of the porous film (A), and the transfer film and the image receptor. A heat-sensitive transfer recording apparatus having at least a heat transfer unit (C) which heats in an overlapping state to form an image on an image receiving surface. 14． 13. The thermal transfer recording apparatus as described in 13 above, wherein the transfer heating source is a thermal head or a laser. 15. 15. The thermal transfer recording apparatus described in 13 to 14 above, wherein the transfer film is arranged in an endless belt shape. 16. 16. The thermal transfer recording apparatus described in 13 to 15 above, which is provided with a sublimation dye supply means having a heating means on the back side of the transfer film (the surface which does not come into contact with the image receptor). 17． A full-color thermal transfer recording apparatus having a yellow image forming section, a magenta image forming section, and a cyan image forming section formed by the thermal transfer recording apparatuses 13 to 16. 18. The thermal transfer recording apparatus for full color according to 17, wherein the image forming section is arranged around the platen roller.

[0012]

【effect】

(1) Operation and Effect Corresponding to Claim 1 By heating the transfer film in which the dye is contained in the pores of the porous film or the resin of the pores and the image receptor, in accordance with the image signal, in a superposed state. The sublimation dye was sufficiently replenished, and a stable image without density unevenness could be repeatedly formed. (2) Action and effect corresponding to claim 2 The porous film is composed of a heat resistant film and has a pore size of 0.
By setting the film thickness to 1 to 100 μm and the film thickness to 1 to 200 μm, an image with high density and good gradation could be stably formed. (3) Action and effect corresponding to claim 3 By filling a resin having good compatibility and diffusibility with a sublimation dye into the holes of a transfer film made of a heat-resistant film, stable operation for maintaining high image quality is achieved. We were able to supply sublimation dyes. (4) Action and effect corresponding to claim 4 A transfer film made of a heat-resistant film has a tapered hole shape, and the hole diameter of one surface is made different from the hole diameter of the other surface to assist diffusion of the sublimation dye. The sublimation dye could be supplied reliably. (5) Operation and effect corresponding to claim 5 By forming the transfer film into an endless belt shape,
We were able to realize stable repeated use of the transfer film. (6) Operation and Effect Corresponding to Claim 6 By using a thermal head or a laser as a heating source for heating an image in accordance with an image signal, it is possible to form minute pixels at a high speed in a system simple manner. (7) Operation and Effect Corresponding to Claim 7 A thermal transfer recording apparatus capable of easily achieving the operation and effect corresponding to claim 1 was produced. (8) Operation and Effect Corresponding to Claim 8 In addition to the effect of (7), a thermal transfer recording apparatus was produced in which full-color image formation was easy.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a recording apparatus used in a heat-sensitive recording method of Example 1.

FIG. 2 is a schematic sectional view of a full-color thermal transfer recording apparatus using the thermal recording method of the present invention.

FIG. 3 is a graph showing the experimental results of Example 1 (relationship between hole diameter of transfer film and image density).

FIG. 4 is a graph showing the experimental results of Example 2 (relationship between transfer film thickness and image density).

[Explanation of symbols]

 1 Sublimation Dye Supplying Means 2 Heating Means (Heating Rollers) 3 Transfer Film 4 Recording Head 5 Image Receptor 6 Platen Roller 7 Cyan Recording Means 8 Magenta Recording Means 9 Platen Rollers 10 Yellow Recording Means 11 Sublimation Dye Coating Means (Sublimation Dye Coating Rollers) 12 blades

Claims (8)

[Claims] 1. A film having a large number of through holes (hereinafter,
Also called a porous film. The heat-sensitive transfer recording method characterized in that the transfer film containing at least a sublimation dye in the holes of (4) and the image receiver are heated in a desired image in a state of being overlapped with each other to form an image on the image receiver. 2. The thermal transfer recording method according to claim 1, wherein the porous film is heat resistant, and has a pore diameter of 0.1 to 100 μm and a thickness of 1 to 200 μm. 3. The heat-sensitive transfer recording method according to claim 1, wherein the transfer film has a through-hole filled with a resin which is compatible with the sublimation dye and has a good diffusion property of the sublimation dye. 4. The thermal transfer recording according to claim 1, 2 or 3, wherein the through-holes of the transfer film are tapered in the thickness direction, and the hole diameter of one surface is different from the hole diameter of the other surface. Method. 5. The thermal transfer recording method according to claim 1, wherein the transfer film has an endless belt shape. 6. The thermal transfer recording method according to claim 1, wherein a thermal head or a laser is used as the transfer heating source. 7. A porous film (A) having a large number of through holes, a means (B) for producing a transfer film by including a sublimation dye in the through holes of the porous film (A), and the transfer film. And a thermal transfer unit (C) for heating an image receiving member in an overlapping state to form an image on the surface of the image receiving member. 8. A full-color thermal transfer recording apparatus having a yellow image forming section, a magenta image forming section and a cyan image forming section formed by the thermal transfer recording apparatus of claim 7.