JPH05338317A - Ink arrangement of thermal transfer printer - Google Patents

Abstract

PURPOSE:To regenerate a smooth uniform ink film continuously on an ink film by removing a wave pattern generated on a surface of the ink film after supplying ink. CONSTITUTION:An ink arrangement of a thermal transfer printer is composed of an inking roller 11 having a cylindrical form, an ink smoothing component 14 consisting of a rod 12 and a rod support base 13, and a smoothing component 16 wherein it is provided to a rear side of an ink-reapplying mechanism along a traveling direction of an ink-keeping film 6, its surface is of a smooth surface property, its central part in a width direction of the ink keeping film 6 is projected in a sectional form, and a reheating heater 17 being a heating means is provided on its back surface. The ink keeping film 6 is travelled while it is being abutted against the heated smoothing component 16 and thereby, a wave pattern of the ink keeping film 6 is restrained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inking device for a thermal transfer printer which prints by repeatedly reusing the ink holding film by applying ink to one surface of the ink holding film.

[0002]

2. Description of the Related Art Conventionally, as an inking device of a thermal transfer printer having a mechanism for re-adhering ink to an ink holding film, a heat-meltable ink is used as an ink material and an ink container is heated to make the ink fluid. A method of repeatedly applying ink to an endless rotatable ink holding film is known (Japanese Patent Publication No. 63-45955). As shown in FIG. 3, the ink reattachment portion of the inking device is an ink storage tank 2 that stores the heat-meltable ink 1.
The heater 3 for heating installed on the lower outer surface of the ink storage tank 2 and a part of the ink 1 in the ink storage tank 2 are rotated by being dipped in the ink, and the ink is transferred to the heat-resistant ink holding film 6. It is composed of an inking roller 4 for supplying 1 and an ink smoothing member 5 for smoothing the ink film thickness.

Here, the inking roller 4 is a Japanese Patent Publication Sho 63
As described in Japanese Patent Application Laid-Open No. 45955/1989, it has a cylindrical shape or a cylindrical shape, and the outer peripheral surface of the inking roller 4 has a circular shape, a grid shape, a triangle shape for supplying ink,
Square or hexagonal recesses, spiral grooves, etc. are formed at equal intervals. Further, as the ink smoothing member 5, a cylindrical or cylindrical rod, or a cylindrical or cylindrical rod in which a wire is closely wound is generally used.

In the inking device of the above-mentioned thermal transfer printer, ink coating is performed as follows. First,
Since the ink is supplied to the ink holding film 6 by transferring the ink held in the concave portion or the spiral groove formed on the outer peripheral surface of the inking roller 4 to the ink holding film 6, the ink holding film 6 In the ink layer transferred on top, a film thickness distribution corresponding to the shapes of the recesses and the spiral grooves occurs. Such an unevenly applied ink layer is smoothed by the ink smoothing member 5, and the ink having a uniform film thickness is applied onto the ink holding film 6.

[0005]

SUMMARY OF THE INVENTION In the above-described conventional inking device for a thermal transfer printer, tension is applied to the ink holding film to apply ink while winding the ink holding film and the ink smoothing member at a certain angle. If the tension of the ink holding film is insufficient, the ink cannot be stably supplied from the inking roller, and the stable smoothing action of the ink smoothing member cannot be obtained. Therefore, it is necessary to apply a certain amount of tension to the film, but since the ink holding film is a very thin film of the order of microns,
The film is pulled in the tension direction, and a wave pattern 7 is generated on the ink holding film as shown in FIG.

When such a wave pattern 7 is generated, a minute gap 8 is formed between the inking roller 4 and the ink holding film 6 as shown in FIG. 4, and the ink supply amount is nonuniform. Further, there is a problem that a minute gap 9 is generated between the ink smoothing member 5 and the ink holding film 6 and unevenness of the ink coating film thickness corresponding to the wave pattern 7 generated on the ink holding film 6 occurs. Therefore, in the conventional thermal transfer printer having the ink re-adhesion portion, there is a problem that it is difficult to print with good print quality because print density change, defective transfer of ink to recording paper, and the like are likely to occur. ..

An object of the present invention is to solve the above problems in the inking device of the conventional thermal transfer printer,
It is an object of the present invention to provide an inking device for a thermal transfer printer that can perform printing with good printing quality by including an inking mechanism that continuously reproduces a smooth and uniform ink film thickness.

[0008]

A first aspect of the present invention is an ink storage tank for storing a heat-meltable ink which is solid at room temperature and whose fluidity increases when heated, and a heating means for heat-melting the ink. Ink is applied to one surface of the heat-resistant ink holding film by an ink reattachment mechanism that includes an ink supply unit that is at least partially immersed in the ink in the ink storage tank, and an ink smoothing member that smoothes the ink film thickness. In the inking device of the thermal transfer printer, which is located behind the ink reattachment mechanism along the running direction of the ink holding film, and includes a smoothing member having a smooth surface texture, and means for heating the smoothing member, It is characterized in that the ink holding film is run while being brought into contact with the smoothing member.

Further, according to the second invention, it is preferable that the smoothing member has a cross-sectional shape in which a central portion of a cross section in the width direction of the ink holding film is convex.

[0010]

The corrugated pattern on the ink holding film is eliminated by causing the ink holding film to run while contacting it on the smoothing member having a smooth surface disposed behind the ink smoothing member. A smooth surface is formed following the surface texture. Here, the cross section of the smoothing member in the width direction of the ink holding film has a shape in which the central portion is convex, and by applying tension in the width direction to the ink holding film, the wavy pattern can be easily eliminated. Becomes In this way, by heating the ink holding film from the back surface with the smoothing member in a state where the wave pattern on the ink holding film has disappeared, the ink is remelted and the fluidity is increased,
A uniform coating film is formed by the surface tension.

[0011]

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

FIG. 1 is a partial sectional view of an embodiment of an inking device of a thermal transfer printer of the first invention.

The inking device shown in FIG. 1 is a solid ink at room temperature, a heat-meltable ink 1, an ink storage tank 2 for storing the ink 1, and an ink attached in close contact with the lower surface of the ink storage tank 2. A heater 3 for heating and an inking roller 11 in which an ink supply groove (not shown) having a V-shaped cross section is formed on the outer peripheral surface of a rotatable cylindrical roller.
And a measuring groove (not shown) is formed in the cylindrical rod 12, the rod 12 is held, and the ink smoothing member 14 is fixed by the rod support 13 fixed to the ink storage tank 2.
A reversing roller 15 for reversing the ink holding film 6,
And a smoothing member 16 having a reheating heater 17 in the lower part.

The ink 1 is, for example, a binder material such as an ester wax to which a colorant such as a pigment is added, and has a melting point of about 80 ° C., which has a relatively low melting point, and increases fluidity when heated. Has been.

The inking roller 11 is rotated in the same direction as the running direction of the ink holding film 6, the ink 1 is drawn up from the ink storage tank 2, the ink is supplied to the ink holding film 6, and the ink smoothing member 14 holds the ink. After smoothing the ink 1 coated on the film 6, about 1
The ink holding film 6 is brought into contact with the smoothing member 16 heated to 00 ° C., and the ink holding film is run.

For comparison, when ink is applied in the same manner without using the smoothing member 16, a wavy pattern is generated on the ink holding film 6 without the smoothing member 16 and the accuracy of the ink film thickness is improved. There is a variation of ± 2 μm in the film thickness,
When the smoothing member 16 is used, the ink film thickness accuracy is ±
Ink coating could be performed with a very high accuracy of 0.5 μm or less.

When the ink holding film 6 coated as described above is used to perform solid black printing with a thermal head (not shown) at 50% duty, the smoothing member 16 is not used. However, when the smoothing member 16 is used, good printing can be performed without unevenness in light and shade.

FIG. 2 is a partial perspective view of an embodiment of the inking device of the thermal transfer printer of the second invention.

In FIG. 2, the smoothing member 16 is composed of a reheating heater 17 and a convex smoothing member 18 having a gentle gradient from both ends toward the central portion and having a convex central portion. The upper surface of the convex smoothing member 18 is in contact with the back surface of the ink holding film 6 that has been recoated with ink. When the ink 1 is re-applied to the ink holding film 6 in the same manner as in the first embodiment of the invention and then passed through the upper surface of the convex smoothing member 18, the shade of the generated wave pattern 7 is convex smooth. It gradually decreases due to the influence of the slope of the converting member 18, the wave pattern 7 disappears, and the ink film thickness accuracy is ± 0.5.
It was possible to perform ink coating with extremely high accuracy within μm.

When the ink holding film 6 coated as described above is used to perform solid black printing with a thermal head (not shown) at 50% duty, the convex smoothing member 18 is not used. When the convex smoothing member 18 is used, good printing can be performed without unevenness in light and shade.

[0021]

As described above, in the inking device of the thermal transfer printer of the present invention, the ink holding film is caused to run while being brought into contact with the heated smoothing member installed at the rear position of the ink re-adhesion mechanism. This has the effect of removing the wave pattern generated on the surface of the ink film after ink supply, realizing extremely uniform ink coating on the ink holding film, and enabling printing with good printing quality.

[Brief description of drawings]

FIG. 1 is a partial sectional view of an embodiment of an inking device of a thermal transfer printer of the first invention.

FIG. 2 is a partial perspective view of an embodiment of an inking device of the thermal transfer printer of the second invention.

FIG. 3 is a partial perspective view of an inking device of a conventional thermal transfer printer.

FIG. 4 is a partial cross-sectional view of an inking device of a conventional thermal transfer printer.

[Explanation of reference numerals] 1 ink 2 ink storage tank 3 heater 4,11 inking roller 5,14 ink smoothing member 6 ink holding film 7 wave pattern 8,9 minute gap 12 rod 13 rod support 15 reversing roller 16 smoothing member 17 Reheater 18 Convex smoothing member

Claims (2)

[Claims] 1. An ink storage tank for storing a hot-melt ink, which is solid at room temperature and whose fluidity increases when heated,
Retaining heat-resistant ink by an ink re-adhesion mechanism including a heating means for thermally melting the ink, an ink supply means for at least partially immersing the ink in the ink storage tank, and an ink smoothing member for smoothing the ink film thickness In an inking device for a thermal transfer printer that coats ink on one surface of the film, a smoothing member that is located behind the ink reattachment mechanism along the running direction of the ink holding film and that has a smooth surface texture An inking device for a thermal transfer printer, comprising: a means for heating a member, and running the ink holding film while contacting the smoothing member. 2. The inking device for a thermal transfer printer according to claim 1, wherein the smoothing member has a convex cross-sectional shape at the center of the cross section in the width direction of the ink holding film.