JPS61280949A - Thermal head - Google Patents

Abstract

PURPOSE:To obtain a light-weight, cheap thermal head having heating elements with greatly improved verticality, base plate's longitudinal portion with greatly improved linearity, and greatly improved thermal efficiency by providing plural heating elements and electrodes on the flat beveled portion formed in the folded potion of the head base plate. CONSTITUTION:A head base plate 1 consists of a stainless steel or carbon steel thin plate 2 whose end is folded into an L-shaped form, with a flat beveled portion partly formed on the folded portion, and an insulating glaze layer 3 formed by baking on the surface. Heating elements 4 of a high-resistance metal compound, e.g., Ta-Si, RuO2, etc., are formed by sputtering, vapor deposition, etc., on the beveled portion 2a of the folded portion of the base plate 2. Separate electrodes 5 and a common electrode 6 to supply voltage to the heating elements 4 are provided on both sides of the elements 4. An end wear-resistant layer 7 is also provided for preventing the oxidation and abrasion by contact with a thermal paper or an ink sheet, etc., of the elements 4. Since the elements 4 come into contact with the platen roller 9 in a cut-in form through the ink sheet of thermal recording paper, the close contact of them can be ensured and the thermal efficiency can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a thermal head used in a thermal recording device.

2. Description of the Related Art Conventionally, this type of thermal head has been predominantly a so-called planar thermal head in which a heating element is formed on a flat surface. However, with the recent spread of thermal transfer recording using thermal transfer type ink sheets, improvements in adhesion to recording paper and ink sheets and thermal efficiency have been sought, for example in JP-A-58.
There is a device in which a heating element is formed on a convex portion, as shown in Japanese Patent No. 138661, and has a configuration as shown in FIG.

That is, a substrate 10 having a rounded end 10a is used, an insulating enamel 11 is fired on the substrate 10, and a heating element 13 is placed on the enamel 11 on the substrate end 10a.
．． A thermal head with electrodes 12 formed thereon is used.

Problems to be Solved by the Invention However, with such a structure, it is difficult to form a uniform roundness at the edge of the substrate 1°, and it is difficult to ensure the straightness of the tip (top) of the roundness. It was also difficult to do so.

Furthermore, when considering the linearity of the heating element due to warpage in the longitudinal direction of the substrate 1o, the substrate 1o needs to be thicker and heavier.゛By the way, in thermal heads used in thermal transfer recording devices that use thermal transfer ink sheets that have recently become widely used, if the heating element part is not straight, contact between the heating element, ink sheet, and recording paper may occur. The condition was non-uniform, causing gaps and scratches in recorded characters and images.

In addition, in attempts to record full-color images using thermal transfer recording methods, which have recently become active, it is necessary to express subtle intermediate tones and record overlapping colors of multiple inks with high precision and good reproducibility. In order to meet these requirements, it was necessary to improve the straightness of the thermal head heat generating/element section and to improve the linearity in the longitudinal direction of the substrate.

Means for Solving the Problems In order to solve the above problems, the present invention uses a thin metal substrate made of stainless steel or carbon steel, bends the end of the metal substrate into an abbreviated shape or a U-shape, and A flat chamfered portion is formed on a part of the metal substrate, an insulating overcoat is baked on the metal substrate to form a head substrate, and a plurality of heating elements and wiring electrodes are attached to the flat chamfered portion of the head substrate. By providing this, a thermal head with good straightness of the heating element and less warping in the longitudinal direction of the substrate is constructed.

According to the thermal head according to the present invention, since the head substrate is constructed by baking an insulating overcoat on a metal substrate with bent ends, bending absorbs warpage of the substrate and straightens the longitudinal direction of the heat generating element. In addition to making it easier to obtain directional linearity, it is also possible to make the head substrate with a thin metal substrate, and also because a part of the bent portion is flattened and a heating element is formed on the chamfered portion. , the straightness of the heating element can be improved, and it is possible to provide a thermal head that is not only capable of recording high-quality characters and images in direct thermal recording and heat-rolling recording, but is also suitable for full-color image recording. It is something.

Embodiment Hereinafter, one embodiment of the present invention will be described based on the accompanying drawings.

In FIG. 1, a head substrate 1 is a thin metal substrate (hereinafter referred to as a thin plate metal substrate made of stainless steel or carbon steel) whose end portion is bent into an abbreviated shape and a flat chamfered portion is formed on a part of the bent portion. (simply referred to as a metal substrate) 2, and an insulating overcoat 3 (an inexpensive material generally called enamel) applied to the surface of the metal substrate 2 by firing.

The chamfered portion 2a formed on the bent portion of the head substrate 2 has a T
A heating element 4 made of a high resistance metal compound such as a-8L or Ru02 is provided by sputtering or vapor deposition.

On both sides of the heating element 4, an individual electrode 5 and a common electrode 6 for supplying electricity to the heating element 4 are provided.

The edge wear layer 7 is provided to prevent the heat generating element 4 from oxidation and wear due to contact with thermal paper, ink sheet, etc.

Next, the operation of one embodiment of the present invention will be explained below.

According to the thermal head according to the present invention, the straightness of the heating element and the linearity in the longitudinal direction of the substrate can be significantly improved compared to conventional so-called planar thermal heads.

By the way, the straightness of the heating element part required for the thermal head during full color recording using the thermal transfer recording method is as follows:
It is 30 to 60 μm or less. However, according to the present invention, the metal substrate 2 is used as a paste material for the head substrate 10 by bending the end portion to absorb warpage and at the same time provide strength, and a portion of the bent portion is, for example, ground, etc. For example, a flat chamfering process of about 0.1 to 1ffiff1 is performed by using the method, and an insulating overcoat 3 is fired on this flat chamfered portion 2a. , the straightness required for the heat generating element portion described above can be fully satisfied.

Further, according to the present invention, a head with good straightness of the heating element portion can be made using the thin metal substrate 2, and the metal substrate 2
Only a slight amount of processing is required, and in addition, the upper medicine 3 was developed in Japanese Patent Application Laid-open No. 1983-
As shown in Japanese Patent No. 138661, it has an inexpensive and well-developed manufacturing method, and can provide an inexpensive thermal head that satisfies performance and functionality.

In addition, since the heating element 4 is provided at the bent portion of the head substrate 1, it comes into contact with the platen roller 9 by being embedded in it through a thermal recording paper or an ink sheet for thermal transfer recording, as shown in FIG. It is expected that adhesion will be improved and thermal efficiency will be improved.

Next, other embodiments of the present invention will be described.

3 and 4 show other embodiments, and FIG. 3 shows L
The shape of the letter-shaped bent part has been changed.

Figure 4 shows a U-shape. Incidentally, those having the same functions as those in the first embodiment are given the same number.

In these embodiments as well, the same effects as in the first embodiment described above can be obtained.

According to the present invention, since the heating element is provided on the flat chamfered portion formed on the bent portion of the head substrate, the heating element and Patterning and formation processes for forming electrodes can be performed easily and accurately.

Effects of the Invention As described above, according to the present invention, it is possible to significantly improve the straightness of the heating element portion and the linearity in the longitudinal direction of the substrate compared to conventional thermal heads, and it is expected that thermal efficiency will be improved. A lightweight and inexpensive thermal head can be provided.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a thermal head according to a first embodiment of the present invention, FIG. 2 is a perspective view thereof, and FIGS. 3 and 4 are sectional views of a thermal head according to another embodiment of the present invention. 5
The figure is a side view showing a recording state, and FIG. 6 is a perspective view of a conventional thermal head. 1...Head board, 2...Metal board,
2a・River... Chamfered part, 3... Insulating top layer, 4...
...Heating element, 5...Individual electrode, 6...
... Common electrode, 7... Wear-resistant layer. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 3

Claims (1)

[Claims] A head substrate whose ends are bent and a flat chamfered portion is formed on a part of the bent portion, and an insulating agent is baked on the surface of the metal substrate, and a flat chamfered portion is formed on the bent portion of the head substrate. A thermal head comprising a plurality of heating elements, and individual electrodes and a common electrode connected to the heating elements on a chamfered portion.