JPH0636924Y2 - Thermal head - Google Patents

Description

[Detailed description of the device]

[0001]

[Industrial applications]

The present invention is a thermal head used in a dry heat recording apparatus,
Particularly, it relates to a thin film type thermal head.

[0002]

[Problems to be solved by conventional techniques and devices]

The structure of a conventional thermal head is shown in FIG. That is, 1
Is an insulating substrate made of alumina or ceramic, 2 is a heat storage body made of glass, 3 is a heating resistor made of silicide such as titanium, vanadium, chromium, molybdenum, zirconium, tungsten, tantalum, and 4 is gold or the like. Reference numeral 5 denotes an electrode made of an alloy such as aluminum, and numeral 5 denotes a protective film made of nitrogen-added silicon or the like. The heat-generating dots 5a in the protective film 5 are recessed by about the thickness of the electrode 4, which is a problem in obtaining efficient applied energy and further in obtaining good print quality. It was

On the other hand, in order to solve the problem caused by the concave heating dots 5a, it has been proposed that the heating dot portions 5b in the protective film 5 have a mesa shape as shown in FIG. With the thermal head having this structure, the contact state with the paper surface is improved for smooth paper, for example, thermal paper or transfer-specific paper, and good print quality can be obtained. However, no improvement in print quality is observed for so-called rough paper having a Beck smoothness of 50 seconds or less. For example, the printing unit of a thermal head with a dot density of 1/180 inch pitch is roughly 140
This is because the printing portion of this size cannot penetrate between the fibers of the rough paper in the printing portion of this size, which results in poor contact between the paper surface and the printing portion.

[0004]

[Means for Solving the Problems]

The present invention has been made based on such a situation, and the heating dot portion in the above-mentioned protective film is formed into a mesa shape, and the heating dot portion is subdivided into a plurality of portions to print between the fibers of the rough paper. It is an object of the present invention to provide a thermal head in which a print portion and a paper surface are in contact with each other as much as possible, and excellent print quality is obtained even on rough paper. That is, according to the present invention, in a thermal head having at least a heating resistor, an electrode and a protective film on an insulating substrate, at least the heating dot portion in the protective film is formed in a mesa shape, and the heating dot portion is The gist is a thermal head characterized by comprising a plurality of subdivided portions.

[0005]

【Example】

Hereinafter, the present invention will be described in detail with reference to the embodiment shown in FIGS. 1 and 2, but in this embodiment, reference is made to the same reference as to a component having substantially the same structure as the thermal head shown in FIG. Numbers are attached.

Reference numeral 1 is an insulating substrate, 2 is a heat storage body, 3 is a heating resistor, 4 is an electrode, 5 is a protective film, and all of these configurations are formed by known materials and manufacturing methods. It is a thing. Reference numeral 6 is a pollution prevention layer provided between the heat storage body 2 and the heating resistor 3 as required. The pollution prevention layer 6 generates heat of alkali ions as impurities in the heat storage body 2. The purpose is to prevent the resistor 3 from entering. The pollution prevention layer 6 is usually made of silicon dioxide, alumina, silicon nitrite, tantalum oxide, silicon carbide, high resistance silicon, or the like.

In the present invention, it is particularly important that the heating dot portion 5b in the protective film 5 is formed in a mesa shape, and the heating dot portion 5b is further subdivided into a plurality of pieces by, for example, various etching methods. In this embodiment, as shown in FIG. 1, are subdivided as a heating dot portions equal square portion 5b ₁ to 6 and _{5b, 5b 2, 5b 3,} 5b 4, 5b 5, 5b 6. Here, each of the subdivided parts 5b
₁ the size _{of, 5b 2, 5b 3, 5b} 4, 5b 5, 5b 6 , the finely divided each of the divided portions 5b _{1 are, 5b 2, 5b 3, 5b} 4, 5b 5, 5b 6 is in rough paper Based on the premise that it penetrates between each fiber (about 30 to 80 μm), 0.06 to about l and m in FIG.
0.07mm or less, which is divided into 5b ₁ , 5b ₂ , 5b ₃ , 5b
The area of b ₄ , 5b ₅ , and 5b ₆ is preferably 0.004 mm ² or less. In addition, each division 5b ₁ , 5b ₂ , 5b ₃ , 5b ₄ ,
The depth of the groove between 5b ₅ and 5b ₆ is 3 μm or more, and more preferably 5 μm or more. However, since the original function of the protective film 5 must not be lost, the thickness of the protective film 5 at the bottom of the groove is not increased. It is necessary to leave the thickness of 1 to 2 μm or more.

In the above-mentioned embodiment, each divided portion 5 formed by finely dividing the heating dot portion 5b in the protective film 5 is formed.
Although the shapes of b ₁ , 5b ₂ , 5b ₃ , 5b ₄ , 5b ₅ and 5b ₆ are quadrangular, the present invention is not limited to this and various shapes such as a circle are adopted. .

[0009]

[Action]

The thermal heads obtained in the above examples were divided into finely divided portions 5b ₁ and 5 when printing on rough paper.
Since _{b 2, 5b 3, 5b 4} , 5b 5, 5b 6 tends to penetrate between the fibers in the rough paper, print quality conventionally is not observed is obtained. Moreover, the divided parts 5b ₁ , 5b ₂ , 5b ₃ , 5b ₄ , 5b ₅ , 5b ₆
Since the groove formed between blocks the transfer of heat in the heating dot portion 5b in the lateral direction, the thermal response is improved and the print edge is sharpened.

[0010]

[Effect of device]

As described above in detail, according to the present invention, in a thermal head having at least a heating resistor, an electrode and a protective film on an insulating substrate, at least a heating dot portion in the protective film is formed in a mesa shape. At the same time, since the heating dot portion is formed into a plurality of subdivided portions, the contact state of the printing portion with the rough paper is particularly good, so that excellent quality printing can be obtained.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of an essential part showing an example of the thermal head of the present invention, FIG. 2 is a top view of the printing portion in FIG. 1, and FIGS. 3 and 4 are conventional examples of the present invention. Is shown.

[Explanation of symbols]

1 ... Insulating substrate 3 ... Heating resistor 4 ... Electrode 5 ... Protective film 5a, 5b ... Heating dot portion 5b ₁ , 5b ₂ , 5b ₃ , 5b ₄ , 5b ₅ , 5b ₆ ... Subdivision Split part

Claims (2)

[Scope of utility model registration request] 1. A thermal head comprising a heating resistor, an electrode and a protective film on at least an insulating substrate, wherein at least a heating dot portion of the protective film is formed in a mesa shape, and a plurality of heating dot portions are formed. A thermal head characterized by comprising a subdivided part of. 2. The printing area of the plurality of subdivided portions is 0.004 mm ²
The thermal head according to claim (1), characterized in that: