JPS63237963A - Edge type thermal head - Google Patents

Abstract

PURPOSE:To improve printing quality by a method wherein a glazed layer of electric insulating material and a plurality of heating elements are provided on an inclined plane composed of a protruding face formed between a main surface and an edge surface of a substrate, and an angle made by the main surface and an extension of the edge surface is made an acute angle. CONSTITUTION:A thermal head 4 is formed as follows. A glazed layer composed of electric insulating material and a plurality of heating elements are provided on an inclined plane composed of a protruding face of 0.1mm<=0.5mm in R the radius of curvature, and an angle made by the main surface and an extension of the edge surface is made an acute angle. Then, a thermal head 4 is, in a sliding manner, contacted with a printing paper 1 supported by a platen 1 via a thermal transfer ink ribbon 3 opposing a heating part to the surface of paper. At the same time, the thermal head 4 is traveled in one direction and the heating part is selectively heated in a specific pattern. Thermal transfer ink is transferred to a printing paper 2 from the ink ribbon 3 and printing is carried out. Therefore, since the heating elements are provided on the inclined plane of a body 4a, a contact area is small, and close adhesion of the ribbon 3 and the paper 2 is excellent. The head is good traveled and printing quality can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an end-type thermal head for use in thermal printers, which is particularly capable of good printing even on coarse paper with large irregularities.

<Prior art> In a conventional thermal head, a thermal transfer ink ribbon is applied to printing paper supported by a platen.
The heat generating part of the thermal head is brought into sliding contact with the surface of the paper with the main surface of the main body of the flat thermal head facing the surface of the paper. Then, the thermal head is sent in one direction to selectively generate heat in the heat generating portion of the thermal head in a predetermined pattern, thereby transferring the thermal transfer ink from the ribbon to the printing paper to perform desired printing.

However, when rough printing paper with large irregularities is used, the adhesion between the thermal transfer ink ribbon and the printing paper deteriorates. Further, since heat easily escapes from the heating element to the head main body, there is a problem that the temperature of the heating element does not rise sufficiently during printing, resulting in a large number of areas where ink is not transferred to the printing paper.

For example, in Japanese Patent Application Laid-Open No. 60-21263, a glaze layer is placed on the flat end of the main body with a width t'(1m≦t'≦2.5m>) so that the surface becomes a curved surface. It has been disclosed that the adhesion between the thermal transfer ink ribbon and the printing paper is improved by forming heating elements in rows on the surface of this glaze layer and reducing the contact area of the heating elements. However, problems occur in head conveyance, etc., and ribbon troubles are likely to occur.Furthermore, providing a heating element on the end face also poses manufacturing problems such as a three-dimensional pattern.

Further, Japanese Patent Application Laid-Open No. 59-171672 discloses a device in which a heating element is provided on an inclined surface between the main surface and the end surface of the main body. However, although such a head improves conveyance and the like, it cannot avoid heat escaping from the heating element to the head body.

<Problems to be Solved by the Invention> In view of these drawbacks of the prior art, the main object of the present invention is to enable good printing even on rough paper with large irregularities;
An object of the present invention is to provide an end-type thermal head free from problems in head conveyance.

<Means for Solving the Problems> According to the present invention, such an object is achieved by reducing the radius of curvature R (0.1 mm≦R≦0.
A glaze layer made of an electrically insulating material and a plurality of heating elements are provided on an inclined surface having a convex surface of 5 m>, and the angle formed by the extended surface of the main surface and the extended surface of the end surface is an acute angle. This is achieved by providing an end-type thermal head characterized by the following.

<Function> In this way, the contact area of the heat generating portion is reduced, and the adhesion between the thermal transfer ribbon and the printing paper is improved. Furthermore, the print quality is improved because the thermal characteristics of the head are improved. Head conveyance also becomes better.

<Embodiment> FIG. 1 shows a thermal printer mechanism to which an embodiment of a thermal head manufactured by a manufacturing method based on the present invention is applied.

A generally flat plate-shaped thermal head 4 is attached to a printing paper 2 supported by a platen 1 via a thermal transfer ink ribbon 3 on an inclined surface 1 between a main surface 8 and an end surface 9 of its main body 4a.
The heat generating part provided at 0 is brought into sliding contact with the surface of the paper so as to face it. At the same time, the thermal head 4 is sent in one direction, the heat generating portion is selectively heated in a predetermined pattern, and the thermal transfer ink is transferred from the ink ribbon 3 to the printing paper 2 to perform the desired printing.

FIG. 2 shows the detailed structure of the thermal head 4. As shown in FIG. For example, the substrate 7 made of a ceramic material such as alumina has an acute angle α between the extended surface of the main surface 8 and the extended surface of the end portion 9, and an inclined surface is formed between the main surface 8 and the end surface 9. 10 are formed. The inclined surface 1Q has a radius of curvature R (0.1 mm≦R
It consists of a convex surface of ≦0.5 m>. Also, the width t of the inclined surface 1Q
' is 0°11rR≦t′≦0.5m, for example, 0°2m, and the glass glaze layer 11 is provided on the surface to have a thickness of 10 to 60 μm.

On the surface of the glass glaze layer 11, an undercoat film 12 made of srO2 or the like is formed by ion blasting on a portion that is to serve as a heat generating portion. A heating resistor 13 made of Ta2N is formed on the surface of the undercoat film 12 by sputtering to a thickness of approximately 500 mm. At the end of the heating resistor 13, an electrode film 14.1 made of Or-Au or the like extends toward the main surface 8 side and the end surface 9 side.
5 is formed in a predetermined pattern by performing photo-etching followed by vapor deposition or the like.

Furthermore, a protective film 16 consisting of two layers of 5102 and Ta205 for wear resistance and oxidation prevention is formed on the surface of the electrode films 14 and 15 by ion blating.

Here, when forming the electrode films 14 and 15, vapor deposition or the like is performed in the direction shown by the arrow in FIG. Therefore, the thickness of the electrode film 14.15 gradually decreases from the end of the heating resistor 13 toward the center. 1
There is no difference in level at the boundary with 3.

In this thermal head 4, since the heat generating portion is provided on the above-mentioned inclined surface 10 of the main body 4a, the contact area becomes small and the close contact between the thermal transfer ink ribbon 3 and the printing paper 2 is improved. Moreover, the head conveyance is also good.

As described above, according to the present invention, since the angle α between the main surface 8 and the end surface 9 is an acute angle, it is difficult for heat to escape from the inclined surface 10, so that the thermal response of the head is improved. be done. Therefore, for example, the substrate can be made of a metal with relatively good workability instead of a ceramic material. Further, if the glaze layer 11 is formed by a vacuum thin film forming process such as sputtering or vacuum evaporation, a layer corresponding to a gray pattern with a uniform and small thickness can be formed regardless of the shape of the head.

It goes without saying that the present invention is not limited to the above-mentioned embodiments and can be applied in various ways. It may be formed with protrusions or the like.

<Effects of the Invention> As described above, according to the present invention, by improving the thermal characteristics of the heat generating part of the thermal head, it becomes possible to use a metal with good workability for the substrate, and it is also possible to use a ribbon or other metal for the substrate. The effect is extremely large because the print quality is improved along with the improved adhesion to the paper.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing how to use a thermal head based on the present invention. FIG. 2 is a sectional view showing the thermal head of FIG. 1 in detail. 1...Platen 2...Printing paper 3...Thermal transfer ink ribbon 4...Thermal head 4a...Main body 7...Substrate 8...Main surface 9...End surface 1
0...Slanted surface 11...Glass glaze layer 12...Undercoat film 13...Heating resistor 14.15...Electrode film 16
···Protective film

Claims (2)

[Claims] (1) Radius of curvature R formed between the main surface and end surface of the substrate
A glaze layer made of an electrically insulating material and a plurality of heating elements are provided on an inclined surface consisting of a convex surface of (0.1 mm≦R≦0.5 mm), and an extension surface of the main surface and an extension surface of the end surface are provided. An end-type thermal head characterized by sharp corners. (2) A distance t' between the main surface side edge and the end surface side edge of the inclined surface satisfies 0.05 mm≦t'≦0.2 mm. The end-type thermal head according to item 1.