JPS6137470A - Heat transfer recording medium and recording method using the medium - Google Patents

Abstract

PURPOSE:To perform heat transfer recording even on recording paper having low smoothness by using a heat transfer recording medium with a heat-meltable ink provided on a heat shrinkable base in heat transfer recording. CONSTITUTION:A heat shrinkable base 1a shrinks when heated at higher than a certain temperature and is formed by elongation process. An ink ribbon is obtained by applying heat-meltable ink 1b on the base 1a. A heating element 3 is heated and a portion of the base 1a which contacts said heating element 3 shrinks longitudinally to increase its thickness. At the same time, the ink 1b also melts and is collected toward a recording dot position by the shrunk portion of the base 1a. Even if some unevenness exists in a recording paper, sufficient ink is supplied even to the concave part of the recording paper 4 through a geometrical effect resulting from the squeeze-in effect of molten ink 1b into the recording surface by thickness increase and the concentric effect of ink to a recording dot position. Thus sufficient transfer is achieved across the size (W) of a proper recording dot.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a thermal transfer recording medium and a recording method using the same.

[Prior art]

An example of an apparatus for thermal transfer recording is as shown in the schematic configuration shown in FIGS. 4 and 5. FIG. 4 is a schematic plan view, and FIG. 5 is a sectional view taken along the line v-■. In the figure, 12 is a platen roller, and 014, which can rotate in the direction of the arrow, is a recording sheet that is a recording medium held on the roller 1-2, and as the platen roller 12 rotates, it is in the direction of arrow B. will be sent to A carriage 16 can reciprocate in the direction of the rotation axis of the platen roller 12, that is, in the direction of arrow C. 18
is a thermal head provided on the carriage 16, sb,
It is possible to move in the direction of the arrow with respect to the carry and ji 16. A supply core 2-0 for supplying an ink ribbon, which is a thermal transfer recording medium, and a next winding core 22 for winding up the ribbon are rotatably held on the carriage 16. The unused one-link ribbon 24 is wound around the supply core 20, and the ribbon 24 is fed out from the supply core 20, passed between the thermal head 18 and the recording paper 14, and then wound onto the take-up core 22. . Therefore, Incresen24
is made to travel in the direction of arrow E.

During recording, the carriage 16 is moved to the right in FIG. While moving the ink ribbon 24 to the direction of the arrow E, the thermal head 18 is moved to the right in FIG. . Appropriate heat pulses are applied to the heating element of the thermal head 18 at appropriate times in accordance with the recording signal.

FIG. 6 shows an enlarged cross-sectional view of the vicinity of the thermal head during recording. In the figure, 19 is a secondary heating element provided in the thermal head 18, and 24a is a base film of the ink ribbon 24 (for example, JP IJ ester film with good heat resistance). ri, 24
b is a heat-melting ink applied on the base film 24a. The ink 24b from the ink ribbon 24 pressed against the recording paper 14 is melted and adhered to the recording paper 14 by the heat generated by the heating element 19. 24c indicates the attached ink, and the used ink ribbon has the attached ink 24e.
Corresponding to this, there is an ink dropout 24d.

By the way, in the thermal transfer recording as described above, the adhesion of the heat-melting ink to the recording paper largely depends on the surface smoothness of the recording paper. That is, ink adheres extremely well to recording paper with good smoothness, but may not adhere completely to recording paper with poor smoothness. FIG. 7 is a sectional view showing this poor adhesion state. In the figure, when the surface smoothness of the recording paper 14 is not good, the actual size of the recording dot is smaller than the proper size W of the recording dot that should be formed by the heat generation of the heating element by one heat pulse. The ink 24c adheres only to the convex portions, and the recorded dots become patchy.

For this reason, in conventional thermal transfer recording, if the surface smoothness of the recording paper is poor for at least 40 seconds, good transfer cannot be performed. However, since thermal transfer recording is characterized by recording on plain paper rather than special paper, it has relatively low smoothness (for example, 10 to 30
[Objective of the Invention] In view of the above-mentioned prior art, the present invention aims to perform good thermal transfer recording even on recording paper with low smoothness. purpose.

[Summary of the invention]

According to the present invention, the above objects are achieved by using a thermal transfer recording medium in which a heat-fusible ink is applied on a heat-shrinkable base in thermal transfer recording.

[Embodiments of the invention]

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic cross-sectional view of an ink ribbon which is an example of the contactor of the present invention. In the figure, 1a is a heat-shrinkable base υ, and 1b is a heat-melting ink.

The heat-shrinkable base 1& is a material that shrinks when heated to a predetermined temperature or higher, and is generally formed by uniaxial or biaxial stretching during or after the production of a resin film, and is not subject to such stretching treatment. Base 1 obtained by
a undergoes heat shrinkage at a temperature below its softening point. Such resin films are made using polyvinyl chloride, polyvinylidene chloride, polyethylene, polypropylene, polydimethyl, polystyrene, chlorinated rubber, and the like. For example, polyethylene and ethylene vinyl acetate are first crosslinked by electron beam irradiation to form a film. Next, the film is stretched while being heated. Next, it is cooled to room temperature while maintaining the stretched state.

Heat-melt ink 1b is applied onto the solid base 1a.
By coating, the incrisene according to the invention is obtained. Ink coating methods include a solvent coating method and a hot melt coating method, but when using the hot melt coating method, it is necessary that the heat shrinkage temperature of the base 1a is higher than the melting temperature of the ink 1b.

FIG. 2 shows the transfer state when thermal transfer recording is performed using the ink ribbon as described above. In the figure, 2 is a thermal head, and 3 is its heating element. 1 is an ink ribbon according to the present invention, 1a is a base of 9p,
lb is ink.

4 is a recording paper with relatively low smoothness. The base 7 of the part that comes into contact with the heating element 3 when the heating element 3 generates heat.
1a contracts in the length direction and increases in thickness. At the same time, the ink 1b is also melted, and at this time, the ink 1b is also collected at the corresponding recording dot position by the amount that the base 1a has contracted. In this way, even if there are some irregularities on the recording paper, the increased thickness of the base 1a will push the molten ink 1b onto the recording surface at the target recording dot position, and the ink will be concentrated at the target recording dot position. Due to the synergistic effect, ink is sufficiently supplied even to the concave portions of the recording paper 4, and complete transfer is achieved over an appropriate recording dot size W.

The shrinkage rate of the base 1a varies from several % to 60% depending on the heating, stretching and cooling conditions during the production of the base 1a.
It can be adjusted within a range of about %. Depending on the recording paper used, a base with a relatively high shrinkage rate can be used for paper with low smoothness, and a base with a relatively low shrinkage rate can be used for paper with high smoothness.

As shown in FIG. 3 (al), the inklitin of this example is of a type that heat-shrinks along the longitudinal direction of the inklitin. Since a ribbon can be used, the recording device can be made smaller and thinner.

As another example, as shown in FIG. 3(b), a type that heat-shrinks along the direction perpendicular to the longitudinal direction of the lithium can be exemplified. This ink ribbon is formed in advance to have a slightly wider width to allow for heat shrinkage. According to this ink ribbon, the winding diameter of the ink ribbon is increased. The recording length of 9271 volumes can be kept constant without any problems.

As another example, as shown in FIG. 3(C), there can be exemplified a type that heat-shrinks along the longitudinal direction of the ribbon and a direction perpendicular to the longitudinal direction. This ink IJ & N is formed in advance to have a slightly wider width to account for heat shrinkage.

According to this ink ribbon, contraction occurs from the entire periphery when heated, so that the above-mentioned pushing effect and ink concentration effect can be further increased.

In the above embodiments, an ink ribbon is exemplified as a thermal transfer recording medium, but the medium of the present invention also includes a sheet-like medium. Regarding the sheet-like media, the types shown in FIGS. 3(a) to 3(e) above can be made with respect to the directionality of heat shrinkability.

According to the thermal transfer recording medium as described above, good recording can be performed even on recording paper with a smoothness of about 10 seconds.

In the thermal transfer recording medium of the present invention, a heat-resistant coating may be applied to the surface of the heat-shrinkable base opposite to the ink side for reinforcement.

〔Effect of the invention〕

According to the thermal transfer recording medium of the present invention as described above, recording paper with low smoothness (for example, paper with a smoothness of 40 seconds or less, even 10
Excellent thermal transfer recording can be performed even when the recording speed is less than 1 second). Furthermore, since the thermal transfer recording medium of the present invention has the effect of concentrating the ink on the recording dot positions, the ink coating thickness can be reduced. Furthermore, in the thermal transfer recording medium of the present invention, since the base has the effect of pressing ink onto the recording paper at the recording dot position, the pressing force of the thermal head can be lowered, thereby extending the life of the thermal head. It can be extended.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of the ink ribbon of the present invention, FIG. 2 is a cross-sectional view of the ink ribbon during thermal transfer recording), and FIG. 3 is a diagram showing the heat shrinkability of the ink ribbon. FIG. 4 is a plan view of the thermal transfer recording device, FIG. 5 is a sectional view taken along the line v-■, and FIG. 6 is an enlarged view of the vicinity of the thermal head at t19 during thermal transfer recording.
This is an i-side view. FIG. 7 is a cross-sectional view of a conventional ink ribbon during thermal transfer recording. 1... Ink ribbon, 1a... Base, 1b...
Thermal S magnetic ink, 2... thermal head, 3... heating element, 4... recording paper. Figure 4 v] 1°

Claims (4)

[Claims] (1) A thermal transfer recording medium characterized in that a heat-melting ink is applied on a heat-shrinkable base. (2) The thermal transfer recording medium according to item 1, wherein the heat shrinkage temperature of the heat shrinkable base is higher than the heat melting temperature of the heat melt ink. (3) The thermal transfer recording medium according to item 1, wherein the medium is ribbon-shaped or sheet-shaped. (4) The heat of the heating element generated in accordance with the recording signal heats the thermal transfer recording medium on which the heat-melting ink is applied on the heat-shrinkable base, shrinking the base of the medium and melting the ink. A thermal transfer recording method characterized by transferring and adhering molten ink to a recording medium.