JPH01202464A - Recording head - Google Patents

Abstract

PURPOSE:To minimize a density reduction caused by the increase of the number of printing sheets and to obtain a recording head having a higher reliability, by a method wherein in a recording head a contact surface with a resistant layer is made high at a recording electrode part and low at a part between recording electrodes. CONSTITUTION:A recording head is made of a recording substrate 1, a drive circuit substrate 2, and a connecting part 3. A recording part has a three layer construction wherein recording electrodes 5 of a high-melting metal is formed on an insulating substrate 4 of a cut ceramics and thereon an insulating layer 7 is formed. In the recording substrate 1, a contact surface with a resistant layer is made high at an electrode part and low at a part between electrodes. In a printing using a recording head constructed as the above, a high contact pressure is applied to a part (a) with low ease of cutting and a low contact pressure is applied to a part (b) with high ease of cutting, which results in approximately the same cut amounts in both the parts. Thus, the contact surface has little possibility of changing in shape due to the increase of the number of printing sheets, a density deterioration of a printed matter is reduced, and a durability is remarkably enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a recording head of a printing device using an electric thermal transfer recording method.

[Conventional technology]

As a printing device using the conventional electrical thermal transfer recording method,
There was a "printing device" (Japanese Patent Application No. 186496/1983). This invention makes it possible to perform area gradation of printed dots using one recording element, and realizes a high-speed, high-quality, and low-cost full-color printing device.

The recording head of a printing device that uses the electrical thermal transfer recording method is
Electricity is applied between two recording electrodes pressed against the resistance layer of the thermal transfer film, melting the heat-melting ink on the thermal transfer film, and transferring it to the printing paper under pressure, which usually results in high-speed recording. For this reason, a line head in which tens to hundreds of recording electrodes are formed on the same plane is used as a recording head.

[Problem to be solved by the invention]

However, in the above-mentioned conventional technology, the recording head and the resistive layer are always in pressure contact during printing, so as the number of prints increases, the contact surface of the recording head with the resistive layer is scraped by the resistive layer. The shape and area will change. In particular, in recording heads where the hardness of the insulating substrate is lower than that of the recording electrodes, the insulating substrate wears out faster than the recording electrodes.
The problem was that the area (section) was scraped off more quickly than the area where the electrode was located (section a in FIG. 1), and the transfer pressure at area b was reduced, resulting in a decrease in the density of the printed matter.

SUMMARY OF THE INVENTION The present invention is intended to solve these problems, and its purpose is to provide a recording head with higher reliability while suppressing the decrease in density due to an increase in the number of prints.

[Means to solve the problem]

In order to solve the above problems, the recording substrate of the recording head of the present invention is characterized in that the contact surface of the recording substrate with the resistance layer is formed high at the electrode portions and low at the portion between the electrodes.

[Function] When printing is performed with the recording head formed as described above, the amount of abrasion in the image area is almost equal because the contact pressure is high in the a part and the contact pressure is low in the a part b, which is easily abraded. , the change in the shape of the contact surface due to an increase in the number of prints is reduced. That is, the rate of decrease in the density of the print due to an increase in the number of prints can be reduced.

〔Example〕

FIGS. 1(a) and 1(b) are diagrams showing the structure of a recording head of a printing apparatus in an embodiment of the present invention. The recording head is composed of a recording substrate 1, a drive circuit board 2, and a coupling portion 3. The drive IC 6 is an IC version of the recording head drive circuit. FIG. 1(b) is an enlarged view of the circle 50 in FIG. 1, showing details of the recording section of the recording head.

The recording section is formed on an insulating substrate 4 made of cuttable ceramics.
It has a three-layer structure in which a recording electrode 5 made of a high-melting point metal is formed, and an insulating layer 7 is further formed thereon. In this example, a machinable ceramic mainly composed of mica was used as an insulating substrate, a thin chromium film was formed thereon by sputtering, and a recording electrode was patterned by etching. The contact portion 10 with the resistance layer has a roughness of 600 using alumina as abrasive grains.
After polishing with a lapping film of about 100 mL to form a flat and uniform surface, place it on plain paper with a thickness of 80 μm and a grain size of 10 μm.
It was formed by polishing diatomaceous earth with a thickness of 15 μm from m to 15 μm using abrasive paper coated with a polyester resin as a binder to a thickness of 20 μm as an abrasive layer. a by this method
The difference in height between the part and the part b is about 5 μm. FIG. 2 shows changes in print density when printing was performed using the recording head in the above embodiment and when printing was performed using a conventional recording head with a flat contact surface. As shown in the figure, with a conventional recording head, the print distance is 20% at a printing distance of 200 m.
However, in the recording head of this embodiment, the printing distance is about 10,000 m even though the density is decreased by 20%, and the durability of the recording head can be greatly improved.

〔Effect of the invention〕

As explained above, the present invention significantly improves the durability of the recording head even if it is made of the same material by making the shape of the contact surface with the resistance layer of the recording head lower in the height of the part between the electrodes than in the electrode part. It has the effect of improving

[Brief explanation of the drawing]

FIGS. 1(a) and 1(b) are diagrams showing an embodiment of a recording head according to the present invention. FIG. 2 is a diagram illustrating changes in print density when the recording head of the embodiment of the present invention is used. ■...Recording substrate 2...Drive circuit board 3...Coupling portion 4...Insulating substrate 5...Recording electrode 7... ...Insulating layer and above Applicant: Seiko Epson Corporation

Claims (3)

[Claims] (1) In a printing device using a thermal transfer film consisting of a heat-melting ink layer that melts when heated and a resistive layer that generates heat when energized, the contact surface of the recording head of the printing device with the resistive layer is , a recording head characterized in that the recording electrode part is high and the part between the electrodes is low. (2) The recording head according to item 1, wherein the contact surface of the recording head is formed by polishing using an abrasive paper coated with polyester resin as a binder and diatomaceous earth as an abrasive layer. (3) The recording head according to item 1, wherein the recording electrode of the recording head has a hardness higher than that of an insulating substrate that is a support for the recording electrode.