JPS60145893A - Thermal recording method by direct use of ink - Google Patents

Abstract

PURPOSE:To obtain clear prints at low cost by a method wherein a solution containing a dye vaporizing at a relatively low temperature is heated to make the dye vaporize, and the dye thus evaporated is made to stick on recording paper through a filter. CONSTITUTION:A solution 6 in which a dye vaporizing at a relatively low temperature is dispersed or dissolved is held in an ink tank 7 provided with a filter (ex. polyvinylidene chloride) 8 which has orifices of a diameter substantially allowing only the vapor of the dye to pass through. Next, a heating body 4 in a thermal head 3 is electrified selectively to heat the solution 6 in the vicinity of the filter 8 and thereby to make the dye vaporize. The dye thus evaporated is made to stick on recording paper 2 through the mesh of the filter 8.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a new recording method that makes it possible to remove a base film in a thermal transfer recording method used in recording devices such as printers and printers.

Figure 1 is an explanatory diagram showing the principle of the conventional thermal transfer recording method.
1 is a transfer film, 2 is a recording paper (recording medium), 3 is a thermal head, 4 is a heating element, and 5 is a pressure roller. As shown in the figure, the transfer film 1 is made by coating a base film 1a such as Mylar film or capacitor paper with an ink layer 1b, and the thermal head 3, transfer film 1, and recording paper 2 are pressed against each other by a pressure roller 5. When the heating element 4 in the thermal head 3 generates heat in response to the surface signal, the ink layer 1b adjacent to the heating element 4 melts, and the ink is transferred to the recording paper 2. As a result, an ink image is formed on the recording paper 2. Note that at the same time as the recording paper 2 runs, the transfer film 1
A new layer of ink is constantly fed out.

However, in the case of this conventional thermal transfer recording method, since the transfer film 1 is constantly fed out, used transfer film is generated every time a desired recorded image is obtained.

Therefore, it is necessary for the apparatus to have a built-in mechanism for winding up the used transfer film 1, or to dispose of the used transfer film 1 after each copy outside the apparatus. Furthermore, although the recording paper 2 is plain paper and is often inexpensive, the transfer film 1 is expensive, and the recording cost per 1 piece is expensive, and it takes time and effort to attach and dispose of the transfer film 1. Ta.

In order to eliminate these drawbacks, the present invention is designed to transfer ink onto recording paper without using a base film. The drawings will be explained in detail below.

(dye dispersed or dissolved in a solvent), 7 is an ink tank, and 8 is a filter. When the heating element 4 of the thermal head 30 is not energized, the ink 6 is completely held by the aggregate of the ink 7 and 8. The filter 8 has a pore size that allows only ink vapor to pass through, and liquid ink 6 cannot pass therethrough. The ink 6 is a solution in which a dye that vaporizes at a relatively low temperature, such as a sublimable dye, is dispersed or dissolved, and when heated above a certain temperature, the dye sublimates and vaporizes. The operating principle is shown below.

The ink 6 near the filter 8 is locally and selectively heated by selectively energizing the heating elements 4 (a large number of which are arranged in a direction perpendicular to the plane of the paper) in the thermal head 3 in accordance with the image signal. Heat and vaporize. The vaporized ink 6 passes through the filter 8, is cooled on the recording paper 2, solidifies, and adheres to the recording paper 2. A desired recorded image is obtained through the above process.

Examples of the filter 8 mentioned here include Yotsu, ethylene chloride, polyvinylidene fluoride, Teflo/, 1
? It is preferable to use a heat-resistant thin film made of Limide, polycarbonate, recycled cellulose, etc., with a large number of holes on the order of μm. Furthermore, a filter that has poor wettability with respect to the solvent to be retained is more effective in preventing fogging. As ink 6, toluene, benzene, acetone,
For solvents such as alcohol and acid-resistant ethyl, PSD-46B/
l/ - (Blue) (Sumitomo Chemical), Kayaset Red 130 (Nippon Kayaku), Kayaset Yellow) TD-
It is a heating element having holes for dispersing a sublimable dye such as N (Nippon Kayaku), and 11 is a lead wire.

The ink vaporized by heating with electricity passes through this hole and reaches the recording paper 2. This embodiment is characterized in that the ink 6 is heated from the recording surface side of the recording paper 2.

Note that the present invention is not limited to black and white recording.

A color image can be obtained by arranging four of these devices in parallel and using yellow, magenta, and black as the respective ink colors.

As explained above, according to the present invention, the drawbacks of the prior art are eliminated, and (1) since the base film is removed in the present invention, handling is simple and customer costs are reduced.

(2) In the present invention, only the ink gas is used for printing, and the ink liquid is completely retained,9 so that sharp printing can be obtained.

(3) Suitable for color recording.

There are other effects.

[Brief explanation of drawings]

Figure 1 is a diagram explaining the principle of the conventional thermal transfer recording method, 1...
Transfer film, 2... Recording paper, 3... Thermal head, 4... Heating element, 5... Pressure roller, 6... Ink, 7... Ink tank, 8... Filter, 9
...Porous 1jj (shaped two-maru\2d, 1o, heat-generating one with pores) Nori-do line Figure 1 Figure 2

Claims (1)

[Claims] 1. Dispersing or dissolving a dye that evaporates at a relatively low temperature in a solvent, and retaining it with a filter that prevents the solution from passing through;
A direct recording method characterized in that the dye is vaporized by selective heating means, passed through holes in the filter, and adhered to recording paper. 2. The ink direct thermal recording method according to claim 1, wherein the dye that vaporizes at a relatively low temperature is a sublimable dye. 3. The ink direct thermal recording method according to claim 1, characterized in that a porous thermal head is used as the heating means. 4. A patent claim characterized in that the filter that holds the solution in which the sublimable dye is dispersed or dissolved has a pore size that is small enough to prevent the solution from passing through, and that also has a pore size that allows the vaporized dye to pass through. The ink direct thermal recording method according to scope 1. 5. The ink direct thermal recording method according to claim 1, wherein the filter is made of a material that has low wettability with respect to a solution in which a sublimable dye is dispersed or dissolved.