JPH02307760A - Thermal transfer type printer head - Google Patents

Abstract

PURPOSE:To enable control of electric current of a heating element to be simplified and to enable contact pressure to be increased by a method wherein heating elements arranged in an anay on a base layer and a protective film layer covering the heating element are established, and a groove is formed to the protective film layer between respective adjacent thermal resistors. CONSTITUTION:A printer head 1 is composed of a heating element anay 2 formed on a base layer and electrodes 3 connected to this heating element anay 2. By making electric current flow to a heating element 6 enclosed by a protective film layer 5 on the base layer 4, heat is generated, and ink of an ink film is transferred to paper by melting the ink of the ink film by said heat. A groove 7 is formed to the protective film layer 5 between the heating elements 6. Therefore, for heat to be generated to the heating element 6, since thermal conductivity of air being the groove 4 is low by comparing with glass or the like composing the protective film layer 5, mutual influence of heat of the heating elements 6 becomes small. That is, necessity for control of electric current according to whether electric current is made to flow to adjacent heating elements 6 or not, disappears. Supposing force pressing the whole of the head is the same, since an area coming in contact with a ribbon is decreased by comparing with a no groove 7 state, pressure per unit area between the ribbon and the head is increased.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a thermal transfer printer head.

[Conventional technology]

Conventionally, this type of thermal transfer printer head is constructed by connecting electrodes to a row of heating elements mounted on a base layer, and covering the electrodes with a layer of protection from heat.

FIG. 3 is a sectional view of a thermal transfer printer head showing an example of such a conventional printer head.

As shown in FIG. 3, in the conventional printer head, a heating element 6 that generates heat when an electric current is passed is arranged on a base layer 4 made of ceramic or the like, and this heating element 6 is covered with a protective film such as glass. Covered with layer 5. These individual heating elements 6 are lined up in a row to form a printer head. The space between these heating elements 6 is uniformly covered with a protective film layer 5. When printing using such a printer head, the heat generated by the heating element 6 melts ink on an ink film (not shown) that comes into contact with it through the protective film N5, and transfers it to paper.

[Problem to be solved by the invention]

In the conventional thermal transfer printer head mentioned above, the heating elements are evenly covered with a protective film layer, so the generated heat is transmitted through the protective film layer, and the heat from adjacent heating elements has a large effect on each other. However, depending on whether or not the current is flowing to the neighboring heating element, the magnitude and duration of the current flowing through the heating element must be controlled, resulting in a situation where printing quality cannot be maintained, and the current cannot be controlled. The disadvantage is that it is complicated. Another drawback is that the contact surface of the conventional printer head with the telephone is large, which reduces the pressure with which the ribbon is pressed against the paper during transfer.

An object of the present invention is to provide a thermal transfer printer head that can simplify the current control of the heating element and increase the contact pressure.

[Means to solve the problem]

The thermal transfer printer head of the present invention includes heating elements arranged in a row on a base layer and a protective film layer covering the heating elements, and grooves are formed in the protective film layer between the heating elements. It is a feature.

〔Example〕

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

- FIG. 1 is a plan view of the thermal transfer printer head of the present invention.

As shown in FIG. 1, the printer head 1 of the present invention includes a heating element array 2 formed on a base layer and an electrode 3 connected to the heating element array 2. As shown in FIG.

FIG. 2 is a sectional view taken along line A--A of the printer head shown in FIG.

As shown in FIG. 2, in this embodiment, heat is generated by passing a current through a heating element 6 surrounded by a protective film layer 5 on a base layer 4, and the ink in an ink film (not shown) is generated by the heat. Transfer it to paper by melting it. A groove 7 is formed in the protective film layer 5 between the heating elements 6. Therefore, the heat generated in the heating elements 6 is less affected by the heat between the heating elements 6 because the heat conduction of the air is poorer than that of the glass forming the protective PIAM 5. In other words, there is no need to control the current depending on whether or not the current is flowing through the adjacent heating elements 6. Further, since the grooves 7 are formed, the scattering of heat is reduced, so printing efficiency is improved.

Furthermore, if the force for pressing the entire head is the same, the area in contact with the ribbon will be smaller than in the case without the grooves 7, so the pressure per unit area between the ribbon and the head will increase. Therefore, the contact pressure between the ribbon and the paper also increases, resulting in better ink transfer.

〔Effect of the invention〕

As explained above, the thermal transfer printer head of the present invention reduces the influence of adjacent heating elements on each other by forming grooves in the protective film layer between the heating elements, making it easier to control the current of the heating elements. It can also form grooves, so
The contact area with the ribbon can be reduced, the contact pressure can be increased to improve ink transfer, and the printing quality can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of the thermal transfer printer head of the present invention, FIG. 2 is a sectional view taken along line A-A of the printer head shown in FIG.
FIG. 3 is a sectional view of a thermal transfer printer head, not showing an example of a conventional printer head.

]...Printer head, 2...Heating element row, 3...
Electrode, 4... Base layer, 5... Protective film layer, 6... Heating element, 7... Beach.

Claims (1)

[Claims] 1. A thermal transfer printer head comprising heating elements arranged in a row on a base layer and a protective film layer covering the heating elements, the protective film layer having grooves formed between the heating elements.