JPS61228968A - Matrix-type thermal printing head - Google Patents

Abstract

PURPOSE:To enable heating parts of heating resistors to be arranged in a high density, by a construction wherein an arbitrary number of the second conductor layers parallel and close to each other intersect with an arbitrary number of first conductor layers parallel and close to each other, and heating resistors are provided between the first and the second conductor layers. CONSTITUTION:The first conductor layers 30 making contact with the lower side of the heating resistors 50 are provided with smaller-width parts 31, while the second conductor layers 40 making contact with the upper side of the resistors 50 are provided with substantially circular opening parts 41. By the resistors 50 parts of which are exposed through the opening parts 41, printing on, for example, a thermal recording paper is conducted. The spacing between adjacent one of the first conductor layers 30 is set to be smaller than the width of the layer 30, and the same applied also to the second conductor layers 40. In the operation of the matrix-type thermal printing head, a voltage is impressed on the first and second conductor layers 30, 40 with a predetermined timing, whereby a predetermined heating resistor 50 is selectively operated to generate heat.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a thermal print head, and more particularly to a matrix type thermal print head in which heat-generating portions, or dots, are arranged in a plurality of rows and columns.

This kind of matrix type thermal print head is shown in FIG. 3 and will be explained according to the same figure.

That is, it is composed of substantially square heating resistors 2 arranged in a matrix on a substrate 1, and a conductor layer 3 connected to the opposite side of each heating resistor 2. One end of each conductor layer 3 is bent and arranged so as not to cause a complicated short circuit between each heating resistor 2, and the other end of each conductor layer 3 serves as a connection terminal (not shown) to connect the substrate. is derived for each side of .

Note that the wiring pattern can be somewhat simplified if the conductor layer 3 that is connected one way is connected in common for each plurality of heat generating resistors 2, but the current applied to each heat generating resistor 2 due to the conductor resistance In order to eliminate variations in the amount, in the thermal print head shown in the figure, consideration is given to keeping the conductor resistance value constant by wiring each heating resistor 2 individually and changing the width of the conductor layer 3.

In this conventional method, a plurality of conductor layers 3 are bent and arranged on the substrate 1 between the heat generating resistors 2, so that each heat generating resistor arranged in a matrix is The distance between the bodies 2 cannot be narrowed beyond a certain level. That is, the heat generating resistors 2 in a matrix cannot be arranged densely. Therefore, the printed surface becomes rough and grainy. Another drawback is that patterning of the conductor layer 3 requires a technique with relatively high precision.

Therefore, it is an object of the present invention to provide a matrix type thermal print head which can be formed using ordinary microfabrication techniques and which can densely arrange the heat generating portions of the heat generating resistors.

Therefore, the present invention provides an arbitrary number of first conductor layers that are parallel to each other and an arbitrary number of second conductor layers that are parallel to each other.
The conductor layers were crossed, and a heating resistor was interposed between the first conductor layer and the second conductor layer. That is, since it has a multilayer structure, each component can be densely arranged using relatively easy processing techniques.

In other words, the first conductor layer and the second conductor layer come into contact with the upper and lower surfaces of the heating resistor.

Hereinafter, one embodiment of the present invention will be described in detail with reference to FIG. 1. FIG. 1 is a perspective explanatory view showing a matrix type thermal print head which is an embodiment of the present invention.

In the same figure, matrix type thermal print head 1
0 is a substantially rectangular plate-shaped substrate 20 made of ceramic or the like;
It is composed of a band-shaped first conductor layer 30 and a second conductor layer 40 made of gold or the like, and a heating resistor 50 made of ruthenium oxide or the like arranged in a matrix.

Specifically, an arbitrary number of first conductor layers 30 are arranged close to each other in parallel on the surface of the substrate 20 . Second conductor layer 4
0 are arranged in an arbitrary number in parallel and close to each other in a direction perpendicular to the longitudinal direction of the first conductor layer 30 . These are formed by, for example, photolithography technology. That is, the first
The conductor layer 30 and the second conductor layer 40 have a substantially lattice shape in plan view, and there is one side between the front surface of the first conductor layer 30 and the back surface of the second conductor layer 40 at each intersection. Approximately square heating resistors 50 whose widths are slightly larger than the widths of the first and second conductor layers 30 and 40 are respectively interposed. The heating resistor 50 is printed using thick film printing technology such as screen printing.
It is formed to have a film thickness of about 0 to 20 μm, and its peripheral surface is tapered to prevent the second conductor layer 40 from being cut off.

Therefore, the first and second conductor layers 30 and 40 are designed to improve the current density in each heating resistor 50. That is, each first conductor layer 30 in contact with the lower surface of the heating resistor 50 has a narrow portion 3 as shown in FIG.
1 is formed, and a substantially circular opening 41 is formed in each second conductor layer 40 that comes into contact with the upper surface of the heating resistor 50. The heating resistor 50, which is partially exposed through the opening 41, is used to print on, for example, thermal paper. Furthermore, the width A between the first conductor layer 30 and the adjacent first conductor layer 30 is made narrower than the width of the first conductor layer 30, but this can be easily achieved using normal microfabrication technology. To the extent possible, the second conductor layer 40 is also made in the same manner.

This matrix type thermal print head uses a normal method in which a voltage is applied to the first conductor layer 30 and the second conductor layer 40 at a fixed timing, and a predetermined heat generating resistor 50 is selected to generate heat as appropriate. It is driven.

As another example, it is also possible to cover the surface of each first conductor layer 30 with a sheet-like heating resistor, and arrange the second conductors 140 on top of this heating resistor. . Even in this case, the heating resistor interposed at the intersection of the first conductor layer 30 and the second conductor layer 40 generates heat locally, so that it is possible to generate heat in a matrix.

11B Riga As explained in detail above, according to the present invention, unlike the conventional method in which a conductor layer is connected to the side of each heating resistor formed in a matrix, the first layer is connected to the lower and upper surfaces of the heating resistor. Since the conductor layer and the second conductor layer are connected to each other, the distance between each of the first and second conductor layers can be significantly narrowed compared to the conventional method. Therefore, it is possible to obtain the effect that the heat generating portions of the heat generating resistor are arranged closely. Moreover, there is an advantage that the processing techniques for forming the first and second conductor layers and the heat generating resistor may be performed with normal accuracy.

[Brief explanation of drawings]

FIG. 1 is a perspective explanatory view showing a matrix type thermal print head which is an embodiment of the present invention, FIG. 2 is an enlarged explanatory view showing the intersection of a first conductor layer and a second conductor layer, and FIG.
The figure is a perspective explanatory view showing a conventional matrix type thermal print head. 10... Matrix type thermal print head 20.
...Substrate 30...First conductor layer 40...Second conductor layer 50...Heating resistor

Claims (3)

[Claims] (1) an arbitrary number of first conductor layers each adjacent to each other in parallel; an arbitrary number of second conductor layers arranged to intersect the first conductor layer and each adjacent to each other in parallel; A matrix type thermal print head comprising: a heating resistor interposed between the conductor layer and the second conductor layer. (2) The heating resistor is locally interposed only at the intersection of the first conductor layer and the second conductor layer. Matrix type thermal print head. (3) The matrix type thermal print head according to claim 1, wherein the heating resistor is in the form of a single sheet.