JPH01209159A - Thermal head - Google Patents

Abstract

PURPOSE:To improve resolving power, to obtain high quality printing and to perform continuous printing or high speed printing, by separating a glass glaze layer for heat insulation between heat generating resistors. CONSTITUTION:A glass glaze layer 2 is provided to a heat insulating substrate 1 and a large number of heat generating resistors 3 are further respectively independently provided thereon in parallel so as to provide a predetermined interval therebetween, and individual electrodes 4 and a common electrode 5 are connected thereto. The glass glaze layer 2 being a heat insulating layer is separated by forming separation parts 7 thereto at every heat generating resistors. Therefore, when a current is selectively supplied to each of the individual electrodes 4 to generate heat from the selected resistor 3, there is not heat conduction between the adjacent heat generating resistors due to the glass glaze layer 2 and heat is separated at every heat generating resistor. Therefore, resolving power is enhanced and high quality printing generating no tailing, blur or the like can be obtained and high speed printing or continuous printing becomes possible.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a thermal head used for thermal recording on thermal recording paper or the like.

[Conventional technology]

Conventionally, as a thermal head, one shown in FIG. 4, for example, is known. The thermal head shown in FIG. 4 has a glass glaze layer 2 as a heat insulating layer on an insulating substrate 1, and a plurality of heating resistors 3 on the glass glaze layer 2, each independently arranged at a predetermined interval. These heating resistors 3 are arranged in parallel, with an individual electrode 4 connected to one end of each, and a common electrode 5 connected to the other end. Figure 5 is a sectional view taken along line D-D in Figure 4;
The figure is a sectional view taken along line C--C in FIG. 4, and a protective layer 6 is provided on the top layer to prevent oxidation and wear resistance of the heating resistor 3. The thermal head configured as described above selectively supplies a drive current to the heat generating resistor 3 from the drive circuit section via the individual electrode 4, and selectively supplies the heat generating resistor 3 to which this drive current has been supplied. At the same time as generating heat, the thermal recording paper is transferred in a direction (X direction in FIG. 4) perpendicular to the arrangement direction of the heat generating resistors 3 (X direction in FIG. 4), thereby creating a dot on the thermal recording paper. By sequentially recording , a desired pattern such as characters or figures is recorded on the heat-sensitive recording paper.

[Problem that the invention seeks to solve]

By the way, in the conventional thermal head as described above, when each heating resistor 3 generates heat to record a pixel on a thermal recording paper, the area between these heating resistors 3 (in FIG. 4) , W), the heat generated by these heating resistors 3 is conducted and stored, resulting in poor thermal isolation between the dots. Therefore, the heating resistor 3
Even in the area between the two, the thermal paper develops color due to this heat, causing tails, stains, blurring, etc. to appear on printed characters, etc., and there is a problem that print quality is likely to deteriorate.

For example, in a conventional thermal head, the heating resistor 3
As shown in FIG. 7, the temperature distribution in the X direction in FIG. 4 when generating heat is the heat storage temperature Ts in the area between the heating resistors 3.
tends to become large, especially when performing continuous printing or high-speed printing.
Since the above-mentioned heat storage temperature Ts increases, correction based on the printing pulse width, etc. is required. Therefore, for a thermal head that performs continuous printing or high-speed printing, it is desirable that the heat storage temperature Ts is small and the slope of the rising curve is large, as shown by the dashed line in FIG.

Generally, as a method of controlling the heat storage temperature, there is a method of controlling heat dissipation in the thickness direction of the heating resistor 3 by changing the thickness of the glass glaze layer 2. However, in this method, only the heat dissipation directly below the heat generating resistors is considered, and it is impossible to lower the heat storage temperature only between the heat generating resistors 3.

As described above, conventional thermal heads have problems in that thermal isolation between heating resistors deteriorates, resulting in tailing, blurring, blurring, etc. in printed images, and deterioration of printing quality.

The present invention was proposed in order to solve these problems, and it is an object of the present invention to provide a thermal head that has good resolution, provides high-quality printing, and is capable of continuous printing and high-speed printing. With the goal.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a thermal head in which a plurality of heat generating resistors are arranged and formed on an insulating substrate, and a glass glaze layer for heat retention. are separated between each of the heating resistors.

[Effect]

Therefore, according to the thermal head of the present invention, there is no glass glaze layer between each heating resistor, so when printing is performed by generating heat from the heating resistor, heat is accumulated in the area between each heating resistor. Therefore, good thermal separation between dots can be achieved.

〔Example〕

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a plan view of main parts showing an embodiment of the present invention, and FIG.
The figure is a sectional view taken along the line A--A in FIG.

As shown in FIGS. 1 and 2, a glass glaze layer 2 is provided on a heat insulating substrate 1, and a plurality of heating resistors 3 are provided independently and in parallel on the glass glaze layer 2 at predetermined intervals. , individual electrodes 4 and common electrodes 5 are connected.

The glass glaze N2, which is a heat-retaining layer, is separated by forming separation portions 7 for each heating resistor.

Therefore, when each individual electrode 4 is selectively energized to generate heat in each heating resistor 3, there is no heat conduction between adjacent heating resistors due to the glass glaze layer 2, and heat is separated from each heating resistor. be done.

As a result, the temperature distribution in the X direction of FIG. 1 is such that the temperature between the heating resistors 3 is only the heat conducted by the protective layer 6, as shown by the solid line in FIG. (shown by the broken line in FIG. 3).

On the other hand, a thermal head having such a configuration is manufactured by a process similar to a conventional manufacturing method.

That is, a continuous glass glaze layer printed and fired on the insulating substrate 1 may be etched by photolithography at the portions between the heating resistors 3 to form separate glass glaze layers 2.

In addition, in the above embodiment, the separation part was formed between adjacent parts, but it may be formed around the entire circumference of each heating resistor 3.

〔Effect of the invention〕

From the above, in the thermal head of the present invention, since the glass glaze layer, which is a heat insulating layer, is separated between each heating resistor,
Thermal separation between dots is improved, and resolution is therefore improved, resulting in high-quality printing without tailing, smearing, blurring, etc., and high-speed printing and continuous printing are possible.

Furthermore, the thermal head of the present invention having the above-mentioned effects also has the advantage that it can be produced by the same process as the conventional photolithography method.

[Brief explanation of the drawing]

Figure 1 is a plan view of essential parts showing an embodiment of the thermal head of the present invention, Figure 2 is a sectional view taken along line A-A in Figure 1, and Figure 3 is the heating resistor arrangement direction (X direction in Figure 1). FIG. 4 is a plan view of essential parts showing an example of a conventional thermal head, FIG. 5 is a sectional view taken along line C-C in FIG. 4, and FIG. 6 is a diagram showing the temperature distribution in FIG. 4. The sectional view taken along the line in FIG. 7 is a characteristic diagram showing the temperature distribution in the heating resistor arrangement direction (X direction in FIG. 4). 1...Insulating substrate 2...Glass glaze layer 3...Heating resistor 4...Individual electrode 5...Common electrode 6...Protective layer and above Applicant Seiko Electronics Industries, Ltd.

Claims (1)

[Claims] 1. A thermal head having a glaze layer and a plurality of heat generating resistors on an insulating substrate, characterized in that the glaze layer is separated between each heat generating resistor.