JPH03189171A - Thermal head - Google Patents

Abstract

PURPOSE:To achieve improvement of printing quality by removing dispersion of printing density in a thermosensible medium by a method wherein an IC storing a flatness data on heating elements arrayed in a line in a principal scan direction or an abrasion resistant film adjacent thereto is established. CONSTITUTION:Since a thermal head is equipped with an IC storing a flatness data on a heating element or on an abrasion resistant film adjacent thereto, operation is performed by using a data converted from A-D at an interval of one heating element content from said flatness data as a correction value, and an electric power quantity to be applied to each heating element is controlled. Dispersion of a transmission quantity of heating value or heat accumulation quantity due to the flatness of a glazed layer and the abrasion resistant film disappears apparently thereby, and a heating value to be transmitted to the thermosensible medium comes not to be dispersed. Consequently, printing density on the thermosensible medium comes not to be dispersed, and improvement of printing quality of the thermal head can be achieved. When the flatness data is read, it is read by measurement along a main scan direction of the heating element and thereby, abovementioned correction value becomes more accurate.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a thermal head as a recording component used in facsimiles, printers, and the like.

Conventional technology In recent years, thermal heads have been widely used in facsimile machines and printers, and demand has rapidly increased.
Demand for higher reliability is increasing.

Hereinafter, an example of the above-mentioned conventional thin film thermal head will be described with reference to the drawings.

FIG. 2 shows the configuration of a general thermal head. In Fig. 2, 1 is an insulating substrate such as alumina, 2
is a glaze layer formed on the insulating substrate 1; 3 is a heating resistor formed on the glaze layer 2 in a line in the main scanning direction of the insulating substrate 1; 4 is a heating resistor formed on the heating resistor 3. a pair of opposing electrodes, 5 is a wear-resistant film formed on the pair of opposing electrodes 4 and the heating resistor 3; 6 is disposed close to the wear-resistant film 5 between the pair of opposing electrodes 4; It is a heat-sensitive medium. And glaze layer 2 is about 40-110
The wear-resistant film 5 has a thickness of approximately 1 μm.
It is around 0 μm. The thickness of the heating resistor 3 and the counter electrode 4 is 1 μm or less. Therefore, the thickness variations mainly depend on the thickness variations of the glaze layer 2 and the wear-resistant film 5.

Conventionally, in this type of thermal head, an I/I that stores data regarding variations in the thickness of the glaze layer 2 and the wear-resistant film 5 is used.
There has never been a thermal head equipped with C and improved recording quality.

Problems to be Solved by the Invention However, in the above configuration, the thicknesses of the glaze layer 2 and the wear-resistant film 5 affect the print density on the heat-sensitive medium 6. If there are variations in the thickness of the glaze layer 2 and the wear-resistant film 5 within one thermal head, the variations will result in variations in the amount of heat transferred or stored, resulting in variations in print density on the thermal medium 6. There were certain issues to be solved.

In view of the above problems, it is an object of the present invention to provide a high-quality thermal head that does not cause variations in print density.

Means for solving the problem In order to solve the above problem, we utilize the fact that the data on the variation in the thickness of the glaze layer and the wear-resistant film can be obtained from the flatness data on the heat-generating resistor or the wear-resistant film in its vicinity. However, the thermal head of the present invention is configured to include an IC that stores flatness data on the heat generating resistors arranged in a line in the main scanning direction or on the wear-resistant film in the vicinity thereof.

Operation The thermal head of the present invention has the above-described structure and is equipped with an IC that stores flatness data on the heat generating resistor or the wear-resistant film in its vicinity. The amount of heat generated by the heating resistor is designed in advance in proportion to the variation in the amount of heat transferred or the amount of heat stored due to the flatness of the heat-sensitive medium. I can do it.

EXAMPLE Hereinafter, a thermal head according to an example of the present invention will be described with reference to the drawings. FIG. 1 shows flatness data on the wear-resistant film on or near the heating resistor in one embodiment of the present invention. In FIG. 1, A is flatness data, and B is a reference line for determining the degree of flatness.

The IC that stores the flatness data on the heating resistor or the wear-resistant film in the vicinity of the heating resistor attached to the thermal head of the present invention is
Data obtained by converting the flatness data of the heating resistor shown in FIG. 1 or its vicinity at intervals corresponding to one shape of the heating resistor is stored.

Furthermore, since the basic configuration of the thermal head is the same as that shown in FIG. 2, the explanation here will be omitted.

The operation of the thermal head having the above IC will be explained below.

An IC that stores flatness data on the heating resistor or the wear-resistant film in its vicinity is attached to the thermal head, and the flatness data can be used as needed. In addition, the above I
C is sometimes mounted on a thermal head.

As described above, according to this embodiment, the data obtained by A-D conversion at intervals of one heat generating resistor from the flatness data on the heat generating resistor or the wear-resistant film in its vicinity is calculated by adding a correction value. By controlling the amount of power applied to each heating resistor, there will be no apparent variation in the amount of heat transferred or stored due to the flatness of the glaze layer and wear-resistant film, and the amount of heat transferred to the heat-sensitive medium will vary. It won't work. As a result, the printing density on the heat-sensitive medium becomes uniform, and the printing quality of the thermal head can be improved. When reading the flatness data, the above correction value becomes more accurate if the heating resistors arranged in the main scanning direction or the wear-resistant film in the vicinity thereof are measured and read along the main scanning direction of the heating resistors.

Effects of the Invention As described above, the present invention can provide flatness data unique to each thermal head by attaching an IC that stores flatness data on the heating resistor or the wear-resistant film in the vicinity thereof. As a result, the printing density on the heat-sensitive medium becomes uniform, and the printing quality of the thermal head can be improved.

[Brief explanation of drawings]

FIG. 1 is a characteristic diagram of flatness data on the heat generating resistor or the wear-resistant film in the vicinity of the heating resistor of a thermal head according to an embodiment of the present invention, and FIG. 2 is a schematic sectional view of the main part of a general thermal head. A: Flatness data.

Claims (3)

[Claims] (1) An insulating substrate, a heating resistor arranged in a row in the main scanning direction on the insulating substrate, a pair of opposing electrodes formed on the heating resistor, and a pair of opposing electrodes to the heating resistor. an I having a wear-resistant film formed thereon, and storing flatness data on the wear-resistant film on or near the heating resistor;
A thermal head characterized by having C. (2) A claim characterized in that the flatness data stored in the IC is data measured along the main scanning direction on heating resistors arranged in a line in the main scanning direction or on a wear-resistant film in the vicinity thereof. The thermal head according to item 1. (3) The flatness data stored in the IC is the data according to claim 2, and is data obtained by A-D converting continuously collected values at intervals of one heating resistor. The thermal head according to claim 1, characterized in that: