JPH0570586B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to an electrical transfer recording device, and more specifically, the present invention relates to an electrical transfer recording device, and more specifically, it melts thermoplastic ink using Joule heat generated by applying electricity to a conductive layer, and transfers the ink to a transfer medium. The present invention relates to an energization recording device for obtaining characters and images.

[Prior art]

Inkjet methods, thermal transfer methods, and the like have been developed and commercialized as full-color image hard copy devices, taking advantage of the merits of each method.

The electric transfer recording device (Japanese Patent Application No. 186496/1986) is a printing device capable of producing hard copies of extremely high-quality full-color images.

The principle diagram is shown in FIG. 1-a.

In the figure, reference numeral 104 denotes a current transfer recording medium, which is composed of a conductive layer 101, a base layer 102, and an ink layer 103. This medium and the transfer paper 105 are stacked, and a pin-shaped recording electrode 106 and a plate-shaped return electrode 1 are stacked.
07 in contact with the conductive layer and a voltage pulse 108
When the ink layer 109 is applied, the ink layer 109 is melted by thermal conduction of Joule heat generated in the conductive layer under the recording electrode, and is transferred to the transfer paper.

Further, as shown in FIG. 1-b, when a pair of pin-shaped recording electrodes is used, the image is transferred as shown at 110 in the figure.

This method is very superior as a printing method aiming at full-color hard copies because the pixel diameter can be controlled by modulating the pulse width of the applied voltage pulse corresponding to each pixel. However, in order to produce very high-quality images, it is necessary to further improve ink transfer reproducibility and transfer efficiency.

In order to improve transfer reproducibility, it is necessary to increase the adhesive force between the ink and the transfer medium to prevent transfer residue from occurring when the ink medium is peeled off. That is, it is necessary to increase the penetration efficiency of the molten ink into the transfer medium.

However, in the conventional method, when thermal energy is supplied, the temperature decreases in the order of the conductive layer, the conductive layer, and the transfer target, as shown in the graph in Figure 2, and once the melted ink penetrates the transfer target paper, As the temperature decreases, the viscosity increases, resulting in insufficient penetration.

In the figure, 201 is a recording electrode, 202 is a conductive layer and a base layer, 203 is an ink layer, and 204 is a transfer paper. This is the temperature distribution in a cross section of paper. The horizontal axis x of the graph is the distance from the electrode surface, and the vertical axis T is the relative temperature.

As described above, in the conventional method, the transfer reproducibility is poor, resulting in defective transfer of pixel dots and degrading the image quality.

〔the purpose〕

SUMMARY OF THE INVENTION An object of the present invention is to improve the above-mentioned drawbacks, that is, to provide an electrical transfer printing device that improves ink transfer reproducibility and enables high-quality hard copies of images.

〔overview〕

That is, a current transfer recording medium having at least a current-conducting layer and an image-receiving layer, and an ink medium having at least a thermoplastic ink layer are placed so that the image-receiving layer and the ink layer face each other, and current is applied to the conductive layer. The object of the present invention is to provide an electrical transfer recording device characterized in that the ink is melted and transferred to the image-receiving layer by the Joule heat generated thereby to form characters and images.

explain in detail.

In order to improve the transfer reproducibility of conventional electrical transfer printing devices, it is effective to raise the temperature of the transfer portion of the transfer medium so that the molten ink sufficiently penetrates into the transfer medium. This effect is particularly noticeable when the environmental temperature is low.

Even in conventional methods, for example, there is a method of applying a thermal bias to the transfer medium, that is, a method of heating the transfer medium from the side opposite to the ink medium using a surface heater, etc., but in this case, the entire surface of the ink is heated. As a result, scumming is likely to occur.

In the method of the present invention, such disadvantages do not occur.

FIG. 3 shows a principle diagram of an example of the present invention.

In the figure, 301 is a conductive layer, 302 is an image receiving layer,
Both constitute an electrical transfer recording medium. 303 is
The thermoplastic ink layer, 304, is a support layer, and together they constitute the ink medium. The current transfer recording medium and the ink medium are installed as shown in the figure, and the recording electrode 306
When more electricity is applied, the ink melts (307),
The image is transferred to the image-receiving layer.

Similar to the above-mentioned FIG. 2, FIG. 4 shows the temperature distribution in the cross section of the current transfer recording medium and the ink medium when thermal energy is generated in this method.

In the figure, 401 is a recording electrode, 402 is a conductive layer, and 4
03 is an image receiving layer, 404 is an ink layer, and 405 is a support layer. The horizontal axis of the graph represents the distance from the electrode, and the vertical axis represents the relative temperature. As shown by the solid line in the graph, when thermal energy is generated, the temperature of the image-receiving layer is high during image reception, promoting penetration of the molten ink and thus improving transfer reproducibility.

〔Example〕

PET film (9μm thick) as ink medium
For this, hot melt coating of thermoplastic ink to a thickness of 3.5 μm was used.

The composition of the ink is shown below.

Polyethylene wax 15wt% Parafine wax 20wt% Carnauba wax 40wt% EVA 15wt% Organic pigment 10wt% As an electrical transfer recording medium, the following was applied to the non-coated side of peach coated paper (manufactured by Nisshinbo) with a coated layer on one side. The conductive paint was solvent-coated and dried. A cross-sectional view is shown in FIG. In the figure, 501 is a conductive layer, 502 is PET
A film 503 is an image-receiving layer made of resin, talc, or the like. Further, the solid content composition of the conductive layer is shown below.

Ketsuen black 25wt% Polyethylene terephthalate 75wt% The surface resistance of the conductive layer was 1.5×10 ³ Ω/□.

The above-mentioned ink medium was wrapped around a rubber platen with the ink layer on the outside, and the current transfer recording medium was stacked with the image receiving layer on the inside to perform current transfer recording.

Transfer reproducibility was evaluated by measuring the dot diameter distribution of transferred pixels. The results are shown in Figure 6.

The horizontal axis is the dot diameter, and the vertical axis is the relative value of the number of dots. As a comparative example, the dot diameter distribution of a conventional method is shown in FIG.

Comparing the two, the method according to the present invention has a sharper dot diameter distribution, that is, better transfer reproducibility.

〔effect〕

As described above, the current transfer recording device according to the present invention melts the ink and heats the image receiving layer when thermal energy is applied to promote ink penetration.
Transfer reproducibility and transfer efficiency are greatly improved.

Therefore, it is most suitable as a hard copy device that achieves high image quality.

[Brief explanation of drawings]

FIGS. 1a and 1b show the principle of a conventional electrical transfer recording apparatus. FIG. 2 shows the temperature distribution in the cross section of the current transfer recording medium and the ink medium when thermal energy is applied in the conventional method. FIG. 3 is a principle diagram of an example of an electrical transfer recording apparatus according to the present invention. Figure 4 shows
FIG. 2 is a diagram showing the temperature distribution in the cross section of the current transfer recording medium and the ink medium when thermal energy is applied in the method of the present invention. FIG. FIG. 5 is a sectional view of an electrical transfer recording medium used in an example of the present invention. FIG. 6 shows the dot diameter distribution of transferred pixels in this example. Figure 7 shows
This is a dot diameter distribution of transferred pixels in a comparative example.

Claims (1)

[Claims] 1. A current transfer recording medium having at least a conductive layer and an image-receiving layer and an ink medium having at least a thermoplastic ink layer are installed so that the image-receiving layer and the ink layer face each other, and current is applied to the conductive layer. An electrical transfer recording apparatus characterized in that the ink is melted and transferred to the image-receiving layer by Joule heat generated thereby, thereby forming characters and images.