JP2584332Y2 - Thermal print head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a thermal printing head.

(Prior Art) FIG. 3 is a partial cross-sectional view of a conventional thin film thermal print head viewed from the side. In the thermal print head 1 of the conventional example shown in FIG. 3, a partial glaze 3 as a heat storage layer is formed on the upper surface on the end side of the insulating substrate 2 by a screen printing method so that the peripheral surface shape as viewed from the side is an arc shape. It is printed and formed. On the upper surface of the insulating substrate 2 including the upper surface of the partial glaze 3, a resistor layer 4 is formed with a small thickness. A window opening 6 is formed on the upper surface of the partial glaze 3 at a position where a resistor layer portion (heating element portion 5) serving as a heating element is exposed.
The conductor layer 7 is formed to have Further, a protective film 9 made of a nitrogen-based material such as silicon nitride, which is excellent in abrasion resistance to the printing paper 8, is formed on the upper surface of the conductor layer 7.
Is formed.

In the thermal print head 1 having such a structure, when a current flows through the conductor layer 7, a current flows from the conductor layer 7 toward the heating element portion 5 in the window opening portion 6 of the conductive layer 7, so that the heating element The portion 5 generates heat, and a predetermined printing is performed on the printing paper 8 by the generated heat.

(Problems to be Solved by the Invention) By the way, in the thermal print head 1 having the above-described structure, as the miniaturization and density increase progress, the formation accuracy of the partial glaze print forming method itself may be low. Therefore, even if the partial glaze 3 is printed on the upper surface of the insulating substrate 2 so as to be deviated from the regular position, or the partial glaze 3 is printed on the regular position, the window-opening portion 6 of the conductor layer 7 remains The possibility of being formed out of position becomes extremely high.

When there is such a displacement, the thermal print head 1 which should be originally positioned at the contact angle as shown in FIG. 3 with respect to the printing paper 8 becomes, for example, as shown in FIG. 4 or FIG. A deviation from the normal contact angle with respect to the printing paper causes a large air layer 10 having poor thermal conductivity between the heating element portion and the printing paper 8. Air layer 10 above
Are caused by sink marks during molding formed on the surface of the protective film 9. Not only the presence of such an air layer 10 makes it difficult to print at a sufficient density on the printing paper 8, but also variations in the mounting position of the head and variations in the mounting angle for each printer. For this reason, unevenness in printing on the printing paper 8 occurs due to a change in thermal conductivity due to a change in the size of the air layer 10, and as a result, high-quality printing cannot be performed.

The present invention has been made in view of the above problems,
It is an object of the present invention to enable high-quality printing by preventing the formation of an air layer between the heating element portion and the printing paper even if there is a displacement during the printing.

(Means for Solving the Problems) In order to achieve such an object, in the present invention, a partial glaze is printed and formed on the upper surface of the insulating substrate, and a resistor layer is formed on the upper surface of the partial glaze. A conductor layer having a window opening is formed at a position where the resistor layer serving as a heating element is exposed on the upper surface of the partial glaze,
Further, a protective film having excellent abrasion resistance to printing paper is formed on the upper surface of the conductive layer, and in a thermal print head which performs printing at a protruding portion formed opposite to a glaze portion of the protective film, A wear layer is formed on the entire upper surface, and the wear layer is worn by the printing paper at the time of initial printing, thereby forming a flat printed portion on the protruding portion of the protective film. And

(Function) Since an abrasion layer excellent in abrasion resistance to the printing paper is formed on the entire upper surface of the protective film, the abrasion layer is worn by the printing paper during the initial printing, so that the abrasion layer is always formed on the protruding portion of the protection film. A flat printing portion is formed, and the printing paper can be brought into close contact with the flat printing portion, so that the printing paper is brought into contact with the thermal printing head without an air layer interposed therebetween. It will be. As a result, heat from the heating element portion of the thermal print head is efficiently transmitted to the printing paper, and high-quality printing can be performed.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a partial cross-sectional view of a thermal print head according to an embodiment of the present invention as viewed from the side. In FIG. 1, the same portions as those of the conventional example are denoted by the same reference numerals, and the description of the portions denoted by the same reference numerals is omitted.

The configuration of the thermal print head 11 of the present embodiment that is different from the conventional example is as follows.

That is, in the thermal print head 11 of the present embodiment, the wear layer 12 made of, for example, SiO ₂ or the like, which is excellent in abrasion on the printing paper 8, is formed on the upper surface of the protective film 9.

The other configuration is the same as that of the conventional example, or the description is omitted.

In the thermal printing head 11 of the present embodiment, as shown in FIG. 2, the wear layer 12 is worn by the printing paper 8 at the initial printing stage, so that the printing paper 8 Can be brought into close contact with each other. Therefore, in the thermal print head 11, no air layer is interposed between the thermal print head 11 and the print paper 8, and heat generated from the heating element portion 5 is efficiently transmitted to the print paper 8.
On the printing paper 8, printing with high density and no printing unevenness, that is, printing with high quality is performed.

(Effects of the Invention) As is apparent from the above description, according to the present invention, the wear layer is worn by the printing paper at the initial printing stage, and the flat printing portion is always formed on the protruding portion of the protective film. Since the thermal print head can contact the printing paper in close contact with the printing paper, even if there is a shift in the printing position of the heating substrate and the partial glaze on the insulating substrate, there is a gap between the heating element and the printing paper. No air layer is generated, and as a result, high-quality printing becomes possible.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view of a thermal print head according to an embodiment of the present invention, as viewed from the side, and FIG. 2 is a partial cross-sectional view for explaining an example of use of the thermal print head of the embodiment. FIG. 3 is a partial cross-sectional view of the thermal print head of the conventional example viewed from the side, and FIGS. 4 and 5 are side views of the thermal print head of the conventional example when the printing position of each component is shifted. It is. 2 ... insulating substrate, 3 ... partial glaze, 4 ... resistor layer, 5 ...
Heating element portion, 6: window opening portion, 7: conductor layer, 8: printing paper, 9: protective film, 11: thermal printing head, 12: wear layer.

Claims (1)

(57) [Scope of request for utility model registration] 1. A partial glaze is printed and formed on an upper surface of an insulating substrate, a resistor layer is formed on an upper surface of the partial glaze, and a resistor layer portion serving as a heating element is exposed on the upper surface of the partial glaze. A conductor layer having a window opening portion is formed at a position, and a protective film having excellent wear resistance to printing paper is formed on the upper surface of the conductor layer, and a protruding portion formed opposite to the glaze portion of the protective film. In the thermal print head for performing printing in the above, a wear layer is formed on the entire upper surface of the protective film, and the wear layer is worn by the printing paper at the time of initial printing, so that the wear layer is formed on the protruding portion of the protective film. 3. A thermal print head according to claim 1, wherein the flat print portion is formed.