JPS62101463A - Thermal head - Google Patents

Abstract

PURPOSE:To sweep away refuse of recording to the exterior of a thermal head and reduce the amount of refuse adhered to the head, by providing a second glaze on the recording paper feeding side of a heating resistors, and setting the gap between a first glaze and the second glaze to within a specified range. CONSTITUTION:A first glaze 12 is provided on an alumina substrate 11 in a substantially symmetrical form with a heat generating resistor row 15 as a center and in a fixed width W of generally 0.3-3mm. On the recording paper feeding direction side of the first glaze 12, a second glaze 14 is provided in a fixed width W' of not less than 0.5mm. Between the first glaze 12 and the second glaze 14 is provided an unglazed part having a fixed width l of 0.3-3mm. A heating generating resistor film 15 and a conductor film are provided on the partially glazed substrate 11 in desired shaped, and the conductor film constitutes a common electrode 13 or conductors branched from the common electrode in rectangular strip forms and individual conductors 16 extended to bonding terminals for an IC.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to the structure of a thermal head, particularly to a partially glazed area.

[Conventional technology]

Figure 2 (A) is from a book that schematically shows a plan view of a conventional thermal head, as in Japanese Patent Application No. 59-187623, and Figure 2 (B) is from the same figure. FIG. 3A is a cross-sectional view taken along line pp' in FIG.

In the figure, 21 is an alumina substrate, 22 is a glaze partially formed on the substrate, and 23 is a conductor that serves as a common electrode and is generally connected to a power source. Also, 24 is a common electrode 2
2 is a conductor branched into a rectangular shape from 3 and connected to the heat generating resistor 25, and 26 is an individual conductor formed by extending from the other end of the heat generating resistor to the connecting terminal to the IC. be. The area shown in the figure is covered by a protective layer or wear-resistant layer of the heating resistor.

In this conventional partially glazed substrate, a layer 25 for the heat generating resistor is formed in a direction perpendicular to the illustrated partial glaze 22, and is further connected to the rectangular conductor 24 and the individual conductors 26 to form the heat generating resistor 25. Configure. The above-mentioned partial glaze is generally provided symmetrically with respect to the resistor in the lower layer of the heat generating resistor 25, and is generated by the heat generated by each heat generating resistor in a thermal head used for the purpose of smoothing the alumina surface and storing heat. The generated heat is conducted to and sinks into the alumina portions at both ends of the resistor.

Therefore, the thermal head has excellent thermal response characteristics.

In addition, the thermal recording paper printed by the resistor 25 is
The colored and molten chemical material is peeled off from the recording paper by friction with the protective layer or the wear-resistant layer intended to protect the resistor, and moves in the feeding direction of the recording paper, for example, as shown in Figure 2 (B).
This results in accumulation of recording debris in the shape shown by the broken line.

The substrate material is generally alumina, enamel, silicon carbide, etc., and the conductor material is generally a base metal such as aluminum, copper, etc., and is also used together with a noble metal such as gold or platinum.

[Problem that the invention seeks to solve]

In the conventional thermal head described above, the glaze slam width W is generally 0.3 to 3ffi, and the glaze thickness is 20 to 60 μm. Further, from this glaze to the recording paper feeding direction side, there is an alumina region with a rough surface over a wide area. For this purpose, as the recording paper runs, the strip individual conductor 2 on the alumina part is moved from the top of the heating resistor.
The above-mentioned molten chemical substance pushed out into the glaze part 4 is swept out from above the glaze part formed in a narrow width and high shape, and accumulates in large quantities over a wide area on the alumina part having a rough surface. When this phenomenon occurs, the recording residue affects the recording state of the printing recording paper, which in turn reduces the printing quality of the thermal head. Furthermore, the printed recording paper may be damaged, or the conductor on the alumina surface, which has a rough surface, may be corroded by halogen elements contained in the molten chemical substance.

[Means for solving problems]

SUMMARY OF THE INVENTION It is an object of the present invention to eliminate the drawbacks and provide a high quality thermal head with a high manufacturing yield.

The thermal head according to the present invention has an alumina region of 0.3 to 3 dew width formed in the gap between the glaze formed on the heating resistor portion and the glaze on the side in the traveling direction of the recording paper from the glaze. A second glaze is provided. Therefore, the recording scum generated during print recording is removed from the thermal head without coming into close contact with the second glaze, which has a smooth surface, and the amount of recording scum adhering to the thermal head is reduced.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1(A) is a plan view schematically showing an embodiment of the present invention, and FIG. 1(B) is a schematic cross-sectional view taken along the line Q-Q' in FIG. . In the figure, reference numeral 11 denotes an alumina substrate, on which a glaze 12 with a width of W is applied symmetrically with respect to the heating resistor row 15. The width of W is generally about 0.3 to 3 snow, preferably about 1 gourd. Also, from this glaze to the recording paper feeding direction side, there is a second
A glaze 14 having a width W' is provided. Width of W′ 0
．． It should be 5 gourds or more, preferably 1 m or more. An anglaze portion with a width of 1t" is formed in the gap with the first glaze 14, and the width of the glaze 12w is 0.3 to 3 degrees, preferably 0.5 to 1.5 degrees. On this partially glazed substrate 11, a heating resistor film 15 and a conductor film are accumulated and formed in a desired shape, and the conductor film is formed on the common electrode 13 or branched into strips from the common electrode. The individual conductors 16 are formed to extend to bonding terminals to the IC.

〔Effect of the invention〕

In the thermal head of the present invention, the second glaze is provided from the heating resistor to the recording paper feeding direction side, and the first glaze is
The gap between the glaze and the second glaze is 0.3'-3-
That is. For this reason, the recording scum generated by printing on the recording paper does not come into close contact with the second glaze, which has a smooth surface, and is swept out of the thermal head.

Therefore, the area to which recording debris adheres is limited only to the alumina area indicated by t''.Therefore, in the thermal head of the present invention, the amount of recording debris to adhere to is reduced to 1/3 or less compared to the conventional thermal head. However, the thermal response characteristics of the printed record are not impaired in any way.Furthermore, there are countless defects in the resistor protective film formed on the alumina region with a rough surface, but the thermal head of the present invention The area of the thermal head is small, and the number of the above-mentioned defects is small.Therefore, the phenomenon of conductor corrosion through defects is reduced, and the manufactured thermal head becomes highly reliable.

Since the thermal head of the present invention exhibits the above-mentioned effects,
The thermal head of the present invention has various characteristics including the application, the resolution of the shaped heat generating resistor, the number of image signal terminals to be input, the number of heat generating resistors that can be driven by a single IC, the IC mounting/connection method, the materials used including the glaze, etc. The manufacturing method, film thickness, manufacturing conditions, etc. are not particularly limited. Furthermore, the glaze can naturally be formed on both sides of the heating resistor glaze with a certain alumina gap. Furthermore, Fig. 1 (
It is also possible to short-circuit the strip-shaped conductor with the common electrode 13 on the first glaze as shown in A). Further, it goes without saying that a conductor such as silver, copper, or gold having a low area resistance can be laminated or buried in the conductor 13 portion on the glaze in order to lower the area resistance of the conductor.

[Brief explanation of drawings]

FIG. 1(A) is a schematic plan view of the vicinity of the heating resistor array according to the embodiment of the thermal head of the present invention, and FIG. 1(B) is a cross section taken along the line Q-Q' in FIG. 1(A). These are schematic diagrams showing the structure, and the resistor protective film or the wear-resistant layer has been removed from these diagrams for convenience. Figure 2 (A) is a schematic plan view of a conventional thermal head, and Figure 2 (B) is the same figure (A).
It is a schematic diagram which shows the cross-sectional structure of the pp' part. DESCRIPTION OF SYMBOLS 11...Substrate, 12...First glaze, 13...Common electrode, 14...Second
glaze, 15... heating resistor, 16...
...Individual conductor. υ squared figure 1 (A) figure 1 CB) east figure 2 (△)

Claims (2)

[Claims] (1) A first glaze provided with a heating resistor, and a distance of 0.3 to 3 mm from the first glaze to the traveling direction of the printed recording paper.
1. A thermal head comprising: a second glaze formed with a gap of a width on a substrate; (2) The thermal head according to item 1, characterized in that the rectangular conductors to be connected to the common electrode are short-circuited to each other on the first glaze having a width of 0.3 to 3 mm. .