JPS6148425B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a printing device, and in particular to a printing device that irradiates a printing medium having a heat sublimable dye layer on its surface with light or heat depending on the image to be printed, and removes the heat sublimable dye in the irradiated area. The present invention relates to a non-impact printing device that performs printing by transferring the image onto a recording paper adjacent to a printing medium.

In conventional non-impact printing devices, such as printers that perform transfer printing by sublimating dye by irradiating laser light, the energy of the laser light must be greater than the threshold energy required to sublimate the dye. The beam diameter (dot diameter) is larger than a certain size determined by the dye. Conventional dyes are micketone (trade name) and resins such as nitrocellulose or polyvinyl alcohol.
It contains a heat sublimable dye such as Dianix (trade name), and there is a natural limit to its threshold energy, and the dot diameter of the laser beam cannot be made smaller than a certain size, so the resolution must be increased. This made it impossible to print thinner than a certain level. Further, since the threshold energy cannot be reduced in this way, that is, the responsiveness of the heat sublimable dye to heat cannot be increased, the printing speed cannot be increased beyond a certain degree. Furthermore, the printing medium in conventional non-impact printers is disposable, and most of the heat sublimable dye on the printing medium is wasted, making it uneconomical in terms of cost.

The present invention has been made in view of the above-mentioned points, and the present invention increases the printing speed by substantially increasing the responsiveness of thermosublimable dyes to heat, and increases the printing speed by substantially reducing the threshold energy of dye sublimation. By reducing the diameter, it is possible to print finely,
Another object of the present invention is to provide a printing device that can effectively utilize the print medium by coating the print medium with a heat sublimable dye and reusing the print medium after printing by irradiation with laser light or the like. Depending on the image to be printed, light or heat is irradiated from the transparent substrate side to a printing medium having a heat-sublimable dye layer on the surface of the transparent substrate via a grounded transparent conductive layer, and the heat-sublimable dye is applied to the irradiated area. In a printing device that performs printing by transferring the image to a recording medium adjacent to the printing medium, the printing medium is constructed in a continuous circulation type, and the surface of the printing medium is sequentially transferred along the circulation direction of the continuous printing medium. a first charging device for applying a polarity opposite to the surface of the printing medium to the surface of the recording medium and applying an electric field between the printing medium and the recording medium in the light or heat irradiation section; 2. A charging device, a dye supply device for applying a thermally sublimable dye solution to the surface of the printing medium, and a heating device for evaporating the dye solvent from the surface of the printing medium coated with the dye solution, and an organic solvent gas discharge device. It is characterized by being provided with.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of an embodiment of a printing apparatus according to the present invention. The laser beam from the laser beam generator 1 is converted into intermittent irradiation light corresponding to the characters to be recorded by the optical deflector 3 according to the print signal through the lenses 2 and 4.
Then, the printing medium 14 is irradiated in the direction of arrow A while being scanned in one direction by the rotating mirror 5 via the mirror 6. The printing medium 14 is a rotating roller 7,
8 and 9 in a continuous belt manner as shown by arrow E. As shown in FIG. 2, this printing medium 14 is made by laminating a transparent conductive film layer 21 on a flexible transparent substrate 20 made of polyimide film or another resin, and a heat sublimable dye layer 22 thereon. The transparent conductive film layer 21 is grounded. A guide drum 10 is provided on the opposite side of the laser beam irradiation part of the printing medium 14, and the recording paper 13 moves in the direction of arrow B.
to guide you. This recording paper 13 faces the heat sublimable dye layer 22 on the surface of the print medium 14. Print media 1
4 in its circulation direction along print media 14
a first corona discharger for uniformly charging the surface of the
A second corona discharger 12 provided on the back side of the recording paper 13 in the laser irradiation section, a dye supply device 23 for applying a thermally sublimable dye solution to the surface of the print medium, a preheater 19 for heating the surface of the print medium, and a printing A heating device 17 is provided for evaporating the solvent of the dye solution from the surface of the medium. The second corona discharger 12 applies charges of opposite polarity to the first corona discharger 11 .
The dye supply device 23 includes a container 15 containing a dye solution in which a heat-sublimable dye is dissolved in an organic solvent such as thinner, and a rotating roller 16 whose surface is made of a flexible porous material for applying the dye solution to the surface of the printing medium. Configure. A hood 18 is provided at the installation part of the heating device 17, and harmful organic solvent gas is discharged as shown by arrow D using a ventilation fan (not shown) or the like.

Next, the operation of the printing apparatus according to the present invention will be explained with reference to FIG.

First, the printing medium 14 is discharged by the first corona discharger 11.
For example, the surface of is uniformly charged negatively (Figure A). Next, as shown in Figure B, a positive charge is applied to the back surface of the recording paper 13 by the second corona discharger 12 while irradiating the laser beam (arrow A). The heat-sublimable dye layer 22 (portion X in Figure B) in the laser beam irradiation area is sublimated by the thermal energy of the laser beam and adheres to the recording paper 13 side (C
figure). At this time, an electric field is formed between the printing medium 4 and the recording paper 13, and the negative charge on the printing medium side is attracted to the positive charge on the back surface of the recording paper, thereby promoting the transfer of the dye to the recording paper. In the next dye supply device 23 (FIG. 1), the rotating roller 16 is
Rotate the heat sublimable dye solution to the printing medium 1.
4, and fill and replenish the dye-defective area in the laser beam irradiated area with heat-sublimable dye (Figure D). Next, after the surface of the printing medium is appropriately heated by the preheating heater 19 (Fig. 1), the heating device 17 heats the heat-sublimable dye solution on the surface of the print medium to evaporate the organic solvent, leaving only the heat-sublimable dye on the print medium. A uniform heat-sublimable dye layer 22 is regenerated by leaving it on the surface (Fig. E). At this time, since the evaporation energy of the organic solvent is much smaller than the sublimation energy of the dye, the thermally sublimable dye is not sublimated by heating by the heating device 17.

Note that an electric field may be created between the print medium and the recording paper by providing a counter electrode on the back surface of the recording paper 13 and applying a voltage between it and the transparent conductive film 21 without using the second corona discharger 12. Further, instead of providing the transparent conductive film layer 21 on the print medium 14 itself, a grounded fixed electrode plate may be provided adjacent to the print medium in each corona discharger installation section.

If the above-described printing apparatus is used, the sublimation transfer action of the thermally sublimable dye is promoted by the charge transfer action caused by the formation of an electric field, so that the irradiation energy of the laser light may be small. Therefore, the reactivity of the dye to heat becomes substantially faster, making it possible not only to increase the printing speed, but also to make fine printing possible because the beam diameter of the laser beam can be small. Furthermore, since the printing medium can be refilled with heat-sublimable dye, the printing medium can be used repeatedly and continuously, which eliminates waste of materials, which is also advantageous in terms of efficiency.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of an embodiment of a printing device according to the present invention, FIG. 2 is a sectional view of an example of a printing medium according to the present invention, and FIG. 3 is a printing diagram showing the operation of the present invention device in order. FIG. 3 is a cross-sectional view of a medium portion. 1: Laser light generator, 11: First corona discharger, 12: Second corona discharger, 13: Recording paper, 1
4: Printing medium, 17: Heating device, 19: Preheating heater, 20: Transparent substrate, 21: Transparent conductive film layer, 2
2: Heat sublimable dye layer, 23: Dye supply device.

Claims (1)

[Claims] 1. Light or heat is irradiated from the transparent substrate side according to the image to be printed on a printing medium having a heat sublimable dye layer on the surface of a transparent substrate via a grounded transparent conductive film layer, and the irradiated area is thermally sublimated. In a printing device that performs printing by transferring a dye to a recording medium adjacent to a printing medium, the printing medium is configured in a continuous circulation type,
A first charging device for uniformly charging the surface of the printing medium in order along the circulation direction of the continuous printing medium; a first charging device for uniformly charging the surface of the printing medium; a second charging device for applying an electric field between the print medium and the recording medium in the heat irradiation section; a dye supply device for applying a heat sublimable dye solution to the surface of the print medium; and printing coated with the dye solution. A printing device characterized in that a heating device for evaporating a dye solvent from a medium surface is provided together with an organic solvent gas discharge device.