JPH0586754B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thermal head in which a heating resistor is formed in the direction of the end surface of a substrate.

More specifically, the present invention relates to a thermal head in which the end surface of a substrate is polished obliquely to the plane of the substrate (hereinafter referred to as oblique polishing), and a heating resistor is attached to this polished surface.

[Conventional technology]

Conventionally, a thermal head in which the end face of the substrate was polished obliquely was developed by the applicant in Japanese Patent Application No. 60-51928.
There is a device that has already been applied for under the No. FIG. 5 is a block diagram showing an outline of this thermal head. The thermal head shown in the figure has a first electrode layer 2, a glass layer 3 serving as an electrical insulating layer and a heat resistance layer, a second electrode layer 4, and a protective glass layer 5 stacked one after another on one surface of a substrate 1. At the same time, each layer including the substrate 1 is cut in a direction perpendicular to the plane of the substrate, and a part of this end face is polished diagonally to cover the exposed polished surface of each electrode layer 2, 4 with a heating resistor. It was designed to be worn. Note that the figure shows the state before the heating resistor is attached in order to clearly show the state of the end surface of the substrate.

FIG. 6 is a sectional view of the thermal head shown in FIG. 5. In the figure, 6 is a heating resistor attached to the obliquely polished surface, and 7 is a protective and wear-resistant layer formed on the heating resistor 6 and at the edge of the substrate. Further, the heat generating resistor 6 is separated into a plurality of parts according to the shape of the first electrode layer 2 constituting the selection electrode. In the example shown in the figure, the heating resistor 6 is attached to the entire end surface of the substrate 1, but the heating resistor 6 is actually used as a heating part between the electrode layers 2 and 4 exposed on the polished surface. Only part.

In the thermal head formed in this way, the heating resistor 6 is attached to the obliquely polished surface, so this surface is pressed against the recording paper, and the contact area with the recording paper is the same as that of the substrate. It is even smaller than the end surface of No. 1, so printing pressure can be lowered and printing quality can be improved.
Furthermore, by changing the angle of oblique polishing, the width' of the glass layer 3 exposed on the polished surface can be changed, so the length of the heating resistor 6 can be easily changed.

[Problem that the invention seeks to solve]

However, in such a thermal head, the polished surface on which the heating resistor 6 is attached has an angle of 90° or more (θ>90°) with respect to the substrate plane. In order to press the substrate 1 evenly against the recording paper, it is not possible to arrange the substrate 1 at right angles to the recording paper (platen), which complicates the design of the printer, such as the mounting method of the head. Particularly in devices such as color thermal printers in which a plurality of thermal heads are arranged close to each other, it is desired that the thermal heads can be arranged at right angles to the recording paper or at an angle close to this.

The present invention eliminates the drawbacks of the conventional apparatus as described above, and provides a simple thermal head capable of polishing the polishing surface for attaching a heating resistor at any angle including 90° to the substrate plane. The purpose is to realize this through configuration.

[Means for solving problems]

The thermal head of the present invention has a plurality of electrode layers stacked one after another on one surface of a substrate so as to face each other with a glass layer serving as an electrical insulating layer and a thermal resistance layer interposed therebetween, and a part of the end surface of this substrate. In the thermal head, the edge of the substrate is polished at an angle to expose the plurality of electrode layers to form a polished surface to which a heating resistor is attached, and the edge of the substrate has an apex angle of 90° with respect to the plane of the substrate. The cut surface is cut in advance into a straight line at an angle greater than 0.degree., and the cut surface is obliquely polished.

[Effect]

In this way, if the edge of the board is cut at an angle greater than 90° in advance, even if the end face is polished at a 90° angle (diagonal polishing), the angle of the board end face and the angle of the diagonal polishing will be different. Since they are not the same, the area in contact with the recording paper does not become large, and the end face to which the heating resistor is to be attached can be obliquely polished at any angle including 90° without losing the characteristics of the diagonally polished thermal head. can do. Therefore, the substrate can be placed at right angles to the recording paper or at an angle close to this.

〔Example〕

Hereinafter, the thermal head of the present invention will be explained using the drawings. In the figure, the above-mentioned figures 5 and 6
Components similar to those in the figures are designated by the same reference numerals.

FIG. 2 shows a state in which the end of the substrate 1 on which the electrode layers 2, 4, etc. are laminated is cut into a straight line at an angle such that the apex angle θ1 with respect to the substrate plane is greater than 90°. Generally, a dicing saw is used to cut the substrate 1, and its cutting angle θ1 is 90°, but if a dicing blade with a tapered angle is used, the substrate 1 can be easily cut at an angle other than 90°. can do.

Therefore, in the thermal head of the present invention, the end face with a certain degree of angle is subjected to oblique polishing. In the figure, if θ2 is the angle of oblique polishing, polishing is performed to the level shown by the broken line. Figure 3 shows the state after polishing. Here, the electrode layers 2 and 4 are exposed on the obliquely polished surface, thereby forming a base surface on which the heating resistor is to be attached.

Now, as shown in FIG. 4, a heating resistor 6 and a protective and wear-resistant layer 7 are formed on the cut and polished end surface of the substrate 1. The process at this time is the same as the conventional one. In other words, even if the end face of the substrate 1 has a certain angle, it is possible to perform diagonal polishing on the end face, and it is possible to reduce the contact area with the recording paper, etc. by making the thermal head diagonally polished. It never loses its characteristics.

Further, FIG. 1 shows the shape of the end face formed by cutting and diagonal polishing when the angle θ2 of diagonal polishing is selected to be 90°. As shown in the figure, when the angle θ2 of the oblique polishing is set to 90°, the polished surface becomes perpendicular to the plane of the substrate, and the heating resistor 6 is attached to this surface, so that the substrate 1 can be used as a recording paper. Can be placed at right angles. At this time, since the edge of the substrate 1 has been cut diagonally in advance, even if the angle θ2 of the diagonal polishing is 90°, the cutting direction of the end surface and the diagonal polishing direction will not match, so the diagonal polishing will not match. The area is kept to the minimum area until the electrode layers 2 and 4 are exposed, and the contact area with the recording paper does not become large.

In this way, if the edge of the substrate 1 is cut in advance in a straight line at an angle such that the apex angle with respect to the plane of the substrate is greater than 90°, heat generation can be achieved without losing the characteristics of the diagonally polished thermal head. The end face to which the resistor is to be attached can be obliquely polished at any angle including 90°.

〔Effect of the invention〕

As explained above, in the thermal head of the present invention, a plurality of electrode layers are successively laminated on one surface of a substrate so as to face each other with a glass layer serving as an electrical insulating layer and a thermal resistance layer interposed therebetween. In a thermal head in which a part of the end surface of the substrate is polished diagonally so as to expose the plurality of electrode layers to form a polished surface to which a heating resistor is attached, the end portion of the substrate is polished to expose the plurality of electrode layers. Since the cut surface is cut in advance in a straight line at an angle that makes the apex angle larger than 90° to the plane, and the cut surface is polished diagonally, the end face is polished at an angle of 90° (diagonal polishing).
Even in this case, the angle of the end surface of the substrate and the angle of diagonal polishing are not the same, so the area in contact with the recording paper does not become large, and the polished surface for attaching the heating resistor is set at 90 degrees with respect to the plane of the substrate. A thermal head capable of polishing at any angle, including angles, can be realized with a simple configuration.

[Brief explanation of the drawing]

1 to 4 are block diagrams showing an embodiment of the thermal head of the present invention, and FIGS. 5 and 6 are block diagrams showing an example of a conventional thermal head. DESCRIPTION OF SYMBOLS 1... Substrate, 2, 4... Electrode layer, 3... Glass layer, 5... Protective glass layer, 6... Heat generating resistor, 7
...protective and wear-resistant layer.

Claims (1)

[Claims] 1 A plurality of electrode layers are sequentially stacked on one surface of a substrate so as to face each other with a glass layer serving as an electrical insulating layer and a thermal resistance layer interposed therebetween, and a heating resistor is provided on the end surface where the plurality of electrode layers are exposed. In the thermal head, the end of the substrate is cut in advance into a straight line at an angle such that the apex angle with respect to the substrate plane is greater than 90°, and a part of this cut surface is cut into the plurality of substrates. 1. A thermal head comprising: a polished surface that is obliquely polished at an arbitrary angle including 90° with respect to a substrate plane so that an electrode layer is exposed; and a heating resistor is adhered to the polished surface.