JPS606480A - Edge type thermal head - Google Patents

Abstract

PURPOSE:To miniaturize a head by shortening the distance from a heat generator to the ends of a substrate and to make it possible to reduce the loss of recording paper, by securing the width of a common electrode by forming the same in a mutually connected and multi-layered form through insulating layers. CONSTITUTION:A thermal head is formed by a method wherein a lower common electrode 8 made of Au is formed on a substrate 1 in a predetermined width (d) and an insulating layer 2 is formed onto said electrode 8 while an upper common electrode 3 made of Au is formed on the insulating layer 2 in the vicinity of the substrate end so as to be connected to the lower common electrode 8 and the projection 3a of the electrode 3, a drive electrode 4 and a heat generating resistor 5 are further formed to be covered with an anti-wear layer 6. As mentioned above, because the common electrodes 3, 8 are formed in a two-layered form and the necessary width (d) is secured by the common electrode 8 under the insulating layer 2, the width of the common electrode 3 can be reduced and the distance from the heat generator 5 to the end of the substrate 1 is shortened to enable the reduction in the loss of recording paper while the head itself is miniaturized. In addition, printing quality can be enhanced as compared with one provided with a reinforcing electrode and a working process is also reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an edge type thermal head.

A conventional thermal head of this type is shown in FIG. In the figure, 1 is a substrate, 2 is a brace layer, 3 is a common electrode, 4 is a drive electrode, 5 is a heating resistor, and 6 is a wear-resistant layer.

FIG. 2 also shows another thermal head, which is further provided with a reinforcing electrode 7.

In the thermal head shown in FIG. 1.2, since a large amount of current flows through the common electrode 3 when the heating element 5 is driven, the width of the electrode 3 is large.

Since the conventional edge-type thermal head is constructed as described above, it has disadvantages such as a long distance from the heating element to the edge of the substrate, resulting in fiber loss.

This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and by forming the common electrode in multiple layers and interconnecting them through insulating layers to ensure the width of the common electrode, The purpose of the present invention is to provide an edge-type thermal head in which the distance from the heating element to the edge of the substrate is shortened.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 shows a drill-type thermal head according to an embodiment of the present invention. In the figure, ■ is the board, 8 is the board 1
2 is a brace layer (insulation M) formed on the substrate 1 to cover the lower common electrode 8; 3 is the substrate end on the place N2; An upper common electrode made of Au is formed nearby and connected to the lower common electrode 8, and the upper common electrode 3 has a plurality of protrusions 3a extending downward in FIG. 4 is a plurality of drive electrodes formed near the edge of the substrate on place N2 between the protrusions 3a of the upper common electrode 3; 5 is a plurality of drive electrodes formed on the brace layer 2 with the protrusions 3a of the upper common electrode 3 and the drive electrode 4; The connected heating resistor 6 is a wear-resistant layer.

Next, the effects will be explained.

In this thermal head, the common electrodes 3 and 8 are made of two layers, and the common electrode 8 below the brace layer 2 secures the necessary width, so the width of the common electrode 3 above the brace layer 2 is reduced. As a result, it is possible to shorten the distance from the heating element 5 to the end of the substrate 1, thereby reducing loss of recording paper, and it is also possible to downsize the thermal head itself.

Furthermore, unlike the one with reinforcing electrodes shown in Figure 2, this thermal head has no protrusions and the head surface is flat, so the heating element and the recording paper have good adhesion, allowing for high-quality printing. can be done, and requires fewer work steps.

In the above embodiment, a common electrode made of Au was provided under the brace layer, but this common electrode does not necessarily have to be made of Au. Further, the common electrode may be formed in two or more layers.

As described above, according to the edge-type thermal head according to the present invention, the common electrode is configured in multiple layers to ensure the width of the common electrode, so the thermal head can be downsized, and there is no loss of recording paper. It has the effect of reducing Furthermore, compared to the case where reinforcing electrodes are provided, excellent printing quality can be obtained, and the number of work steps can be reduced.

[Brief explanation of drawings]

Figures 1(a) and 1(b) are a plan view and a cross-sectional side view of a conventional edge-type thermal head, respectively, and Figure 2 (1al)
(b) is a plan view and a sectional side view of a conventional 7-edge type thermal head, respectively, and FIG. It is a side view. 1... Substrate, 2... Brace layer (insulating layer), 3.8
...Common electrode, 5...Heating resistor. In the drawings, the same reference numerals indicate the same or equivalent parts. Agent Masuo Oiwa Figure 1 (b) = 7- to a

Claims (1)

[Claims] (11) In an edge-type thermal head having a heating resistor near the edge of the substrate, the common electrode is formed in multiple layers and interconnected through an insulating layer, and the common electrode of the uppermost layer is connected to the heating resistor. An edge type multi-head, characterized in that the distance between the heating resistor and the edge of the substrate is formed to be small.