JPH09277706A - Thermal transfer printing method, thermal transfer printing apparatus, and, ink ribbon used therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To print with high quality even on plain papers of poor surface quality, by transferring a transparent or white binder onto a recording medium, heating and smoothing a surface. SOLUTION: An ink ribbon 30 has, on a thin film 31, an area where a binder UC is applied, an area of an exposed part NC where the thin film 31 is exposed, and areas where melting type inks Y, M, C are applied. The ink ribbon 30 and a recording paper are overlapped between a thermal head and a platen roller. A current is fed to a heat-generating resistance body of the thermal head, thereby to generate heat at the thermal head. As a result, the binder UC applied onto the ink ribbon 30 is melted thereby to form an undercoat to the recording paper. Then, the ink ribbon 30 is transferred and a part of the exposed part NC where the binder UC is applied is heated by the thermal head, so that a surface of the binder UC is smoothed. The ink ribbon 30 is further transferred, and the inks Y, M, C are sequentially melted or sublimated by the thermal head to be transferred to the recording paper.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer printing method, a thermal transfer printing apparatus, and an ink ribbon used for the method, which can perform high-quality printing even on plain paper having a poor surface property.

[0002]

2. Description of the Related Art FIG. 4 is a diagram showing a general structure of a thermal transfer printing apparatus. The ink ribbon 3 and the recording paper 4 are superposed between the thermal head 1 and the platen roller 2, and an electric current is passed through the heating resistor 1a of the thermal head 1 to generate heat. Due to this heat generation, the ink applied to the ink ribbon 3 is melted or sublimated and transferred to the recording paper 4. In addition,
The ink ribbon 3 is formed by applying three colors of yellow (Y), magenta (M), and cyan (C) or four colors of ink with black (K) added thereto.

By the way, in order to obtain a good printed image on the recording paper 4, it is necessary that the surface property of the recording paper 4 is good. Plain paper such as postcards has poor surface properties and cannot be printed with high image quality. Therefore, for such recording paper, an ink ribbon coated with a transparent or white binder UC and inks Y, M, and C as shown in FIG. 5 is used, and the binder UC is coated on the recording paper. There is a thermal transfer printing apparatus that first obtains a good surface property (by so-called undercoating) and then applies inks Y, M, and C to obtain a printed image.

[0004]

However, even if the surface property is improved by the undercoat, a sufficient image can be obtained by the binary image recording, but a high quality image cannot be obtained by the multi-gradation image recording. Improvement was desired. The present invention has been made in view of such problems, and in a thermal transfer printing method and a thermal transfer printing apparatus in which a binder is applied to a recording medium and ink is transferred onto the binder, a higher quality image can be obtained. It is an object of the present invention to provide a thermal transfer printing method and a thermal transfer printing apparatus that can be obtained, and to provide an ink ribbon suitable for use in the thermal transfer printing method and the thermal transfer printing apparatus.

[0005]

In order to solve the above-mentioned problems of the prior art, the present invention provides (1) a thermal transfer printing method in which thermal fusion printing or thermal sublimation ink is used for thermal transfer printing on a recording medium. A first step of transferring a transparent or white binder onto the recording medium, a second step of heating the binder to smooth its surface, and a binder smoothed by the second step. A thermal transfer printing method comprising: a third step of transferring an ink onto the recording medium; and (2) a thermal transfer printing apparatus for performing thermal transfer printing on a recording medium using a heat-meltable ink or a heat sublimable ink. A thermal head, a platen roller, a first area coated with a transparent or white binder on the thin film, a second area where the thin film is exposed, and ink. An ink ribbon on which the applied third region is formed, the ink ribbon and the recording medium are superposed between the thermal head and the platen roller, and the binder is melted by the thermal head. A means for transferring the binder onto the recording medium, the ink ribbon and the recording medium are superposed between the thermal head and the platen roller, and the binder transferred onto the recording medium by the thermal head is transferred to the recording medium. The ink ribbon and the recording medium are superposed between the thermal head and the platen roller by heating the ink ribbon through the second region to smooth its surface, and And a means for transferring the ink on the binder. Providing a printing apparatus, the ink ribbon subjected to (3) thermal transfer printing,
A first area coated with a transparent or white binder on the thin film, and a second area where the thin film is exposed.
The present invention provides an ink ribbon characterized by cyclically forming a region (1) and a third region coated with a heat-meltable ink or a heat-sublimable ink in this order in the longitudinal direction.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The thermal transfer printing method of the present invention is described below.
A thermal transfer printing apparatus and an ink ribbon used for the same will be described with reference to the accompanying drawings. FIG. 1 is a perspective view showing an embodiment of an ink ribbon used in the thermal transfer printing method and thermal transfer printing apparatus of the present invention, and FIGS. 2 and 3 are diagrams for explaining the operation of the thermal transfer printing method and thermal transfer printing apparatus of the present invention. Is.

According to the research conducted by the inventor of the present invention, the reason why a high quality image cannot be obtained even if an undercoat is applied is that the surface roughness of the recording paper 4 is more than the binder UC applied as an undercoat. The binder UC itself, which is applied as an undercoat, has poor smoothness and has large application unevenness. The amount of heat applied during undercoating is too large, the binder UC permeates the recording paper 4, and the surface properties of the recording paper 4 are affected. It became clear.

The schematic structure of the thermal transfer printing apparatus of the present invention is the same as that of FIG. 4 in the conventional example, and the ink ribbon used for it and the operation at the time of printing are different from those in the conventional example. Therefore, first, an ink ribbon used in the thermal transfer printing method and thermal transfer printing apparatus of the present invention will be described.

In the ink ribbon 30 of the present invention, as shown in FIG. 1, a thin film 31 is coated with a first region on which a transparent or white binder UC is applied, and the thin film 31.
And a third region coated with the heat-meltable ink or the heat-sublimable ink Y, M, C is cyclically formed in this order in the longitudinal direction. is there. In this example, the ink ribbon 30 has three colors of Y, M, and C, but it may have four colors by adding K to this.

In the thermal transfer printing method and the thermal transfer printing apparatus of the present invention, printing is performed as follows using such an ink ribbon 30. Similar to FIG. 4, the ink ribbon 30 and the recording paper 4 are superposed between the thermal head 1 and the platen roller 2, and a current is passed through the heating resistor 1a of the thermal head 1 to generate heat. Due to this heat generation, first, as shown in FIG. 2 (A), the binder U applied to the ink ribbon 30.
C is melted and the recording paper 4 is undercoated. At this time, the binder UC may be transferred onto all of the recording paper 4, but it is desirable that the binder UC be transferred onto the portion where the image is printed with the inks Y, M, and C in substantially the same area as the image. When the inks Y, M, and C are thermally sublimable inks, the binder UC contains resins having a property of accepting the thermally sublimable inks.

Next, the ink ribbon 30 is conveyed by a means (not shown), the portion coated with the binder UC at the exposed portion NC is heated by the thermal head 1, and as shown in FIG. Smooth the surface. Since the heating by the exposed portion NC is for smoothing the surface of the binder UC, the ink ribbon 30 is not always necessary.
It is not necessary to heat through the exposed portion NC formed in the above, but this can be said to be the most preferable embodiment. Also,
Even if the exposed portion NC is thinly coated with the binder UC, the surface of the binder UC on the recording paper 4 can be made smooth. Then, the ink ribbon 30 is conveyed by means (not shown), and the inks Y, M, and C are sequentially melted or sublimated by the thermal head 1 and transferred to the recording paper 4 (on the binder UC).

In the printing process as described above, it is desirable to set the heating temperature of the binder UC and the exposed portion NC and the heating temperature of the inks Y, M and C within the temperature range shown in FIG. That is, the binder UC is heated above its melting temperature and transferred onto the recording paper 4. In the heating by the exposed portion NC, only the surface of the binder UC is melted and the binder UC is prevented from soaking into the recording paper 4.
The heating temperature is the same as or slightly lower than the heating temperature. The heating temperatures of the inks Y, M, and C are set to be the same or higher for the ink to be transferred later so that the melting temperature of the ink to be transferred later does not decrease. That is, if the melting temperatures of the inks Y, M, and C are y, m, and c, y = m =
c, y = m <c, y <m = c, y <m <c can be selected, and it can be said that the most preferable embodiment is y <m <c.

Table 1 shows the experimental results obtained by the thermal transfer printing method and thermal transfer printing apparatus of the present invention.

[0014]

[Table 1]

The high-quality paper (surface roughness of 8 μm or less) has a relatively smooth surface and is easy to write on, and can be said to be the standard as plain paper. When this high-quality paper is used as the recording paper 4,
The binary image can be used without undercoating, but the multi-tone image does not have good ink adhesion in the low-tone portion. When the binder UC is transferred and then heated by the exposed portion NC, the surface roughness of the binder UC becomes small regardless of the coating amount of the binder UC, and the surface property is improved. However, in this case, the coating amount of the binder UC is 5 g /
If it is about m ² , the surface property is improved by itself, so
It can be seen that it is sufficient to set the coating amount of the binder UC to about 5 g / m ² for high-quality paper.

The copy paper A (surface roughness 8 to 10 μm) has a rougher surface than the high-quality paper, so the amount of binder UC applied is 5
It can be seen that g / m ² is not sufficient and 8 g / m ² or more is necessary. For copy paper B (surface roughness 10 to 15 μm), the coating amount of binder UC of 8 g / m ² is insufficient,
It is understood that 10 g / m ² or more is required. For postcards (surface roughness 15-20 μm), the coating amount of binder UC is 1
It can be seen that 0 g / m ² is not enough, and 15 g / m ² or more is necessary.

From the above, it is necessary to increase the coating amount of the binder UC as the surface roughness of the recording paper 4 is rougher, and even if the surface property of the coated binder UC is poor, the surface property will be improved by heating by the exposed portion NC. It was confirmed to be improved. At this time, if the heating amount is too large, the applied binder UC melts and permeates the recording paper 4 and is affected by the surface roughness of the recording paper 4. Therefore, as described above, the surface of the applied binder UC is It is heated at a temperature that melts.
In this way, a good printed image can be obtained by the thermal transfer printing method and thermal transfer printing apparatus of the present invention.

[0018]

As described in detail above, the thermal transfer printing method and thermal transfer printing apparatus of the present invention transfer a transparent or white binder onto a recording medium and heat the binder to smooth its surface. Since the ink is transferred onto the smoothed binder, high-quality printing can be performed even on plain paper having a poor surface property. In addition, the ink ribbon of the present invention has a first region in which a transparent or white binder is applied on a thin film, a second region in which the thin film is exposed, and a heat-meltable ink or a heat-sublimable ink. Since the applied third region is cyclically formed in this order in the longitudinal direction, it is extremely suitable for realizing the thermal transfer printing method and thermal transfer printing apparatus of the present invention.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of an ink ribbon of the present invention.

FIG. 2 is a diagram for explaining the operation of the thermal transfer printing method and thermal transfer printing apparatus of the present invention.

FIG. 3 is a diagram for explaining the operation of the thermal transfer printing method and thermal transfer printing apparatus of the present invention.

FIG. 4 is a diagram showing a general configuration of a thermal transfer printing apparatus.

FIG. 5 is a perspective view showing an example of a conventional ink ribbon.

[Explanation of symbols]

 1 Thermal Head 2 Platen Roller 4 Recording Paper 30 Ink Ribbon 31 Thin Film NC Exposed Area UC Binder Y, M, C Ink

Claims (3)

[Claims] 1. A thermal transfer printing method for thermal transfer printing on a recording medium using a hot-melt ink or a thermal sublimation ink, comprising: a first step of transferring a transparent or white binder onto the recording medium; A thermal transfer printing method comprising: a second step of heating and smoothing the surface thereof; and a third step of transferring ink onto the binder smoothed by the second step. 2. A thermal transfer printing apparatus for thermal transfer printing on a recording medium using a hot-melt ink or a sublimable ink, wherein a thermal head, a platen roller, and a thin film are coated with a transparent or white binder. An ink ribbon having a first region, a second region where the thin film is exposed, and a third region where ink is applied are formed, and the ink ribbon is provided between the thermal head and the platen roller. And a recording medium are superposed on each other, a unit for melting the binder by the thermal head to transfer the binder onto the recording medium, and the ink ribbon and the recording medium between the thermal head and the platen roller. The binder transferred onto the recording medium by the thermal head is overlaid, and the ink revolving is performed. And a means for heating the surface of the binder to make the surface smooth by the second area, the ink ribbon and the recording medium are superposed between the thermal head and the platen roller and A thermal transfer printing apparatus, characterized in that it is provided with means for transferring ink. 3. An ink ribbon used for thermal transfer printing, comprising: a first region coated with a transparent or white binder on a thin film; and a second region exposed with the thin film.
And the third region coated with the heat-meltable ink or the heat-sublimable ink are cyclically formed in this order in the longitudinal direction.