JPH0480049A - Thermal head - Google Patents

Abstract

PURPOSE:To carry out high quality photographic printing with a low energy by a method wherein a glaze glass is formed in a trapezoid form and besides its short side aspect is formed virtually parallelly to a substrate. CONSTITUTION:A glaze glass 2A formed in a trapezoid form is formed so that its short side aspect 2a becomes virtually parallel to a substrate 1 and besides this aspect 2a is so formed as to protrude above a conductor layer 4. A thermal transfer sheet 7 and image receiving paper 8 exist between a thermal head and a platen roller 9, and receives appropriate pressing force of the thermal head. A heating element layer 3 obtains a photographic printing signal, and a current flows via the conductor layer 4, which is heated to high temperature. Heated thermal energy is transmitted to a thermal transfer sheet 7 via an oxidation resistance layer 5 and an abrasion resistance 6. At that time, the abrasion resistance layer sticks fast to the thermal transfer sheet 7, and thermal energy is effectively transmitted. An ink component of the thermal transfer sheet 7 is transferred to the image receiving paper 8 thereby, and an image having followed the photographic printing signal is formed.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention is directed to, for example, arranging a plurality of heating resistor elements linearly on the same substrate and heating the heating resistors with electricity according to a desired pattern to produce thermal paper. The present invention relates to a thermal head that performs color recording on paper or transfers and records onto plain paper via an ink ribbon.

[Prior Art] FIG. 5 is a sectional view showing a conventional thermal head disclosed in, for example, Japanese Patent Laid-Open No. 61-74862. In the figure, (1) is an insulating substrate made of ceramic such as alumina, (2) is a thin glazed glass fired on the substrate (1), and (3) is about 0.05 to 0.3μ made of TaJ etc. (3a) is the heating dot part, (3a) is the heating resistor layer with a thickness of
4) is a conductor layer made of AI2 or the like and has a thickness of about 1 to 2 μm and supplies current to the heat generating resistor layer (3); (5) is a conductor layer of Sin;
The heating dot part (3a) of the heating resistor layer (3)
(6) is a Ta
2es, etc. to prevent the surface of the thermal head from being worn out due to friction with thermal recording paper or thermal transfer sheet 3
In FIG. 6, which is an example of the use of a conventional thermal head having an abrasion resistant layer with a thickness of about 5 μm, (7) shows a thermal transfer sheet, (8) shows an image receiving paper, and (9) shows a platen roller.

The thermal head is pressed against the platen roller (9) with a thermal transfer sheet (7) and image receiving paper (8) interposed therebetween using appropriate pressure. The heating resistor layer (3) receives a printing signal, a voltage is applied through the conductor layer (4), and a current flows. As a result, the heating resistor layer (3) generates heat to a high temperature. The generated thermal energy is transferred to the thermal transfer sheet (7) via the oxidation-resistant layer (5) and the wear-resistant layer (6). This thermal energy causes the ink components of the thermal transfer sheet (7) to be transferred to the image receiving paper (8), forming an image according to the printing signal.

[Problem to be solved by the invention 1 Since the conventional thermal head is configured as described above, the adhesion between the thermal head and the thermal transfer sheet (7) is poor, and the oxidation-resistant layer (5) and the thermal transfer sheet (7) ), an air layer (10) was present between the two, significantly reducing heat transfer efficiency. Therefore, it is necessary to increase the amount of heat generated by the heating element, which causes problems such as significantly shortening the life of the thermal head and deteriorating the quality of printed images.

Also, during the manufacturing process, glazed glass (
If the center (11) of 2) and the center (12) of the conductor layer (4) are misaligned, the contact state between the thermal head and the thermal transfer sheet (7) will change significantly, as shown in Figure 8, and the print quality will deteriorate. There was always a problem when it became a factor of variation.

The present invention was made to solve the above-mentioned problems, and an object of the present invention is to obtain a thermal head that can print with low energy, has a long life, and can print with high image quality.

[Means for Solving the Problems] A thermal head according to the present invention is one in which a glaze glass is formed into a trapezoid shape, and the short side surface thereof is substantially parallel to the substrate.

[Function] In the thermal head according to the present invention, since the glaze glass is trapezoidal, the contact area with the thermal transfer sheet is increased, and the heat transfer efficiency is improved. This makes it possible to perform printing with less applied energy and prevent deterioration of the life of the heating element. Furthermore, it is possible to prevent contact variations due to manufacturing misalignment between the glaze glass and the conductor layer.

[Embodiment] An embodiment of the present invention will be described with reference to FIGS. 1 to 4. Fig. 1 is a cross-sectional view, Fig. 2 is a cross-sectional view showing an example of the use of Fig. 1, and Figs. 3 and 4 are cross-sectional views showing the state when the center of the glaze glass and the center of the conductor layer are misaligned. Components that are the same as or equivalent to those of the conventional device are designated by the same reference numerals, and description thereof will be omitted. In the figure, (2A) is a trapezoidally formed glaze glass, and its short side surface (2a) is formed to be almost parallel to the substrate (1), and this short side surface (2a) is It is formed to protrude upward from the conductor N(4).

In FIG. 2, a thermal transfer sheet (7) and an image receiving paper (8) are interposed between a thermal head and a platen roller (9), and are subjected to an appropriate pressing force from the thermal head. The heating resistor layer (3) receives a printing signal and current flows through the conductor layer (4). As a result, the heating resistor H(3) generates heat to a high temperature. The generated thermal energy is transferred to the thermal transfer sheet (7) via the oxidation-resistant layer (5) and the abrasion-resistant layer (6). At this time, the abrasion-resistant layer (6) and the thermal transfer sheet (7) are in close contact with each other. As a result, thermal energy is efficiently transferred. This thermal energy causes the ink components of the thermal transfer sheet (A) to be transferred to the image receiving paper (8), forming an image according to the printing signal.

Figure 3 shows the manufacturing process of the thermal head, and shows the center (11) of the trapezoidal glaze glass (2A) and the conductor layer (4).
Fig. 4 shows an example of the use of Fig. 3, but from this figure, the short side surface (2a) of the substrate (1) and the trapezoidal glaze glass (2A) It can be seen that when they are parallel, the thermal transfer sheet (7) and the thermal head can be in close contact.

If the short side surface (2a) of the glaze glass (2A) is made to protrude above the conductor layer (4) as in the above embodiment,
Close contact with the thermal transfer sheet (7) is further improved.

[Effects of the Invention] As described above, according to the present invention, since the thermal head and the thermal transfer sheet are configured in a shape that makes it easy for them to come into close contact with each other, thermal efficiency is improved, and a thermal head with a long life and good printing quality can be obtained at a low cost. There is.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing a thermal head according to an embodiment of the present invention, FIG. 2 is a cross-sectional view showing an example of use of FIG. 1, and FIG.
Figure 4 is a cross-sectional view showing the state when the center of the glaze glass and the center of the conductor layer are fused together, Figure 5 is a cross-sectional view showing the conventional one, and Figure 6 is an example of the use of Figure 5. The cross-sectional views, FIGS. 7 and 8, are cross-sectional views showing a state in which the center of the glaze glass and the center of the conductor layer are misaligned. In the figure, (1) is the substrate, (2A) is the glazed glass, (2a) is the short side of the glazed glass (3) is the heating resistor layer, (3a) is the heating dot, and (4) is the conductor layer. ,(
5) and (6) are protective layers, and (7) is a thermal transfer sheet. Note that the same symbols in each figure indicate the same or equivalent parts.

Claims (2)

[Claims] (1) A substrate, a glazed glass formed on the substrate, a heating resistor layer formed on the glazed glass and the substrate, a conductor layer formed on the heating resistor layer, and a heating dot. and a protective layer formed after removing the conductive layer on the upper part of the thermal head, the glaze glass is formed into a trapezoidal shape, and the short side surface of the glaze glass is made to be substantially parallel to the substrate. A thermal head characterized by: (2) The thermal head according to claim 1, wherein the trapezoidal short side surface of the glaze glass projects upwardly from the conductor layer.