JPS6225068A - Thermal printer head - Google Patents

Abstract

PURPOSE:To print in high quality irrespective of type of recording sheet by forming a plurality of heaters at the end of an insulating substrate on a crest- shaped projection formed on the end of the substrate to construct a thermal printer head, thereby eliminating printing irregularity. CONSTITUTION:A projection of the prescribed length is formed in a crest shape on the end of an insulating substrate 10 to form a thin heater layer 12. An electrode layer 13 of NiCr or Au and a common electrode 15 are thinly formed on the layer. A protective film 17 is eventually coated to form a thermal printer head 18. The head 18 is contacted only at the projection 11 with a recording sheet 19, and the other portion of the substrate 10 is separated from the sheet 19. Thus, a printing irregularity can be eliminated to print in high quality irrespective of the kind of the sheet 19.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention transfers characters and figures onto recording paper by melting an ink ribbon by selectively generating heat from a heating element. The present invention relates to a thermal printer head of a so-called thermal transfer type thermal printer.

Prior art thermal printers are broadly classified into thermal transfer type and thermal type. Among these, a conventional example of a thermal transfer type thermal printer will be described with reference to FIGS. 7 and 8. That is, a chevron-shaped protrusion 2 is formed on a flat insulating substrate 1. This protrusion 2 is a glass glaze layer, and is formed slightly closer to the ends than the center of the insulating substrate 1. .

A plurality of heating elements 3 are arranged in a line at the apex of the projection 2, and these heating elements 3 have a common electrode 4 patterned on the insulating substrate 1 and individual ftL poles 5. are connected. The common electrode 4 is commonly connected to all of the heating elements 3, and the individual electrodes 5 are
It is individually connected to each of the heating elements 3. A thermal printer head 6 is formed here.

Therefore, the thermal printer head 6 is connected to the recording paper 7.
The heating element 3 is pressed against the recording paper 7 at a right angle. therefore.

The recording paper 7 and the insulating substrate 1 are arranged in parallel.

In such a configuration, when the common #i pole 4 and the individual electrodes 5 are selectively energized, the heating element 3 generates heat, the ink ribbon 9 is melted, and this is transferred onto the recording paper 7. Characters and figures are drawn on the recording paper 7 by selectively assembling the thus transferred materials.

Problems to be Solved by the Invention In recent years, thermal transfer type thermal printers are required to have the ability to perform high quality printing on recording paper 7 having poor smoothness, so-called rough paper. Therefore, the surface of the rough paper is smoothed by the pressing force of the heating element 3, and then printing is performed. However, the thickness from the insulating substrate 1 to the tip of the heating element 3 is 10
Since it is only 0 μ or less, the rough paper cannot be smoothed depending on the pressing force of the heating element 3, and the ink cannot be applied to the concave portions of the rough paper. Therefore, there is a drawback that printing becomes uneven and high-quality printing cannot be performed. On the other hand, even if the pressing force of the heating element 3 against the rough paper is increased, the insulating substrate 1 and the like collide with the bulging portions of the rough paper, making it impossible to smooth the rough paper as well. Therefore, high quality printing cannot be performed.

The present invention was made in view of these points.

To obtain a thermal printer head capable of performing high-quality printing regardless of the type of recording paper.

Alternative Means for Solving the Problems In the present invention, a chevron-shaped protrusion is formed at the end of an insulating substrate, and a plurality of heating elements are formed on this protrusion closer to the end of the insulating substrate than the center.

In this way, one heating element is pressed against the recording paper. When these heating elements are selectively energized, they generate heat, and characters and figures are transferred onto the recording paper.

On the other hand, when the heating element is pressed against the recording paper, only the protrusions contact the recording paper, and other parts such as the insulating substrate are separated from the recording paper. As a result, the pressing force of the heating element against the recording paper can be increased, and even if the recording paper is rough paper, the portion pressed by the heating element is smoothed, and ink also adheres to the dented portions of the recording paper. therefore,
Printing unevenness is eliminated, and high-quality printing is performed regardless of the type of recording paper.

Embodiment of the Invention A first embodiment of the present invention will be described with reference to FIGS. 1 to 3. A flat insulating substrate 10 is provided, and a protrusion 11 of a predetermined length is formed in the shape of a chevron at the end of the insulating substrate 10. The insulating substrate IO is made of alumina or the like, and the protrusion 11 is a glass glaze layer formed by a thick film printing method or the like. And, the protrusion 11 has Ta-8
A heating element layer 12 such as i○2 is formed as a thin film, and the heating element layer 12 is formed as a thin film on top of the heating element layer 12, which extends to the apex of the protrusion 11 to form the insulating substrate 10.
An electrode layer 13 made of NiCr, Yasu, etc. spreads over almost the entire surface of the
is formed as a thin film. These thin films are formed by sputtering, vacuum evaporation, or the like. The heating element layer 12 and the electrode MJ13 are patterned by first etching. That is, the heat generating layer 12 is divided into a shape arranged in a line in the longitudinal direction of the protrusion 11, and accordingly, the electrode layer 13 is also divided into a plurality of pieces to form an L-shape. The electrode layer 13 forms a plurality of individual electrodes 14 . These individual electrodes 14 are selectively plated with metal.

Thus, a common electrode 15 is formed as a thin film in a space above the insulating substrate 10, extending to the end of the heat generating layer 12 and covering the entire area. This common electrode 15 is made of NiCr, Au, or the like, is formed by sputtering, a vacuum vapor chamber method, or the like, and is partially plated with metal. - On the other hand, the heating element layer 12 has an exposed part between the part covered with the electrode layer 13 and the part covered with the common electrode 15, and this exposed part serves as the heating element 16. . These heating elements 16 are formed offset from the apex of the protrusion 11 toward the end of the insulating substrate 10 .

Further, the insulating substrate IO is finally covered with a protective film 17. This protective film 17 is +Ta2o5 or AQ2
03 or the like is formed into a thin film by sputtering, vacuum evaporation, or the like. Here, the thermal printer head 18
is formed.

The thermal printer head 18 is arranged to face the platen 20 on which the recording paper J9 is wound, with an ink ribbon 21 interposed therebetween, and the heating element 16 is connected to the recording paper J9.
2 is pressed at right angles.

Therefore, the insulating substrate 10 is arranged to be inclined at a predetermined angle with respect to the recording paper 22.

In such a configuration, the individual *poles 14 and the common electrode 15
When selectively energized, the heating element 16 generates heat, and the portion of the ink ribbon 21 in contact with the heating element 16 is melted and transferred onto the recording paper 19. Characters and figures are drawn on the recording paper 19 by selectively assembling the transferred materials.

On the other hand, in the thermal printer head 18, only the protrusion 11 contacts the recording paper 19, and other parts such as the insulation wall plate 1O are separated from the recording paper 19.

Therefore, if the pressing force of the heating element 16 against the recording paper 19 is increased, even if the recording paper 19 is rough paper, the heating element 16
The area pressed by the recording paper 19 becomes smooth, and the ink adheres to even the recessed areas of the recording paper 19.

This eliminates printing unevenness and allows high-quality printing to be performed regardless of the type of recording paper 19.

Further, since the first heating element 16 is arranged at the end of the insulating substrate 10, the width of the common electrode 15 becomes narrow. As a result, the common electrode 1
The resistance value of the heating element 5 increases, causing a voltage drop, and the voltage applied to the heating element 16 varies, which tends to cause uneven print density.
Therefore, in this embodiment, the individual electrodes 14 and the common electrode 15 are plated with metal to suppress the resistance value of the common electrode 15 from increasing. Therefore, unevenness in print density is prevented from occurring, contributing to high quality printing.

In addition, as a modification, the occurrence of uneven print density may be prevented by increasing the resistance value of the heating element 16 or by increasing the thickness of the common pole 15. This is because if the resistance value of the heating element 16 is increased, the heating element 16 will generate sufficient heat even if a voltage drop occurs. As another modification, the resistance value of the short individual electrodes 14 may be increased, and the resistance value of the long ones may be decreased.

As a result, the voltage drop is balanced, and unevenness in print density is also prevented.

Next, a second embodiment of the present invention will be explained based on FIGS. 4 to 6. The same or corresponding parts as in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment, the insulating substrate 10 on the side where the protrusion 11 is formed
The end portion is sloped to form a sloped portion 22, and this sloped portion 2
The common fPL pole 15 was made to go around 2.

This prevents a voltage drop across the common electrode 15 and prevents uneven print density from occurring. Further, since the inclined portion 22 is inclined, it does not come into contact with the recording paper 19, and high-quality printing can be performed regardless of the type of recording paper 19.

In practice, the protrusion 11 may be formed by providing a protrusion at a predetermined position on the insulating substrate IO and forming a glass gelase layer on the protrusion. Moreover, the inclined part 22
The shape may be tapered or arcuate. Furthermore, it may be applied to a thick film head.

Effects of the Invention The present invention forms a chevron-shaped protrusion at the end of an insulating substrate,
Since a plurality of heating elements are disposed closer to the edge of the insulating substrate than the center of the protrusion, high-quality printing can be performed regardless of the type of recording paper.

Therefore, the types of recording paper that can be used are increased, and if the insulating substrate is formed with an inclined part by slanting the end side from the position where the protrusion is formed, and a common electrode is formed on this inclined part, This has effects such as stabilizing the amount of voltage applied to the heating element, preventing uneven print density, and contributing to high quality printing.

[Brief explanation of drawings]

FIG. 1 is an overall plan view showing the first embodiment of the present invention, FIG. 2 is a longitudinal side view of the vicinity of the heating element, and FIG. 3 is a side view showing the arrangement of the thermal printer head, recording paper, etc. , 4th
5 is a plan view of the entire structure; FIG. 6 is a side view showing the arrangement of the thermal printer head and recording paper; and FIG. FIG. 7 is an overall plan view showing a conventional example, and FIG. 8 is a side view showing the arrangement of a thermal printer head, recording paper, etc. 10...Insulator, 11...Protrusion, 16...Fever application person Tokyo Electric Co., Ltd. gogouta, yen≦1,, ¥5u mouth, %'? 'Kun (shape)', %d figure (wings)

Claims (1)

[Claims] 1. A chevron-shaped protrusion is formed at the end of the insulating substrate, and a plurality of heating elements are disposed on the protrusion closer to the end of the insulating substrate than the center. Thermal printer head. 2. The thermal printer according to claim 1, characterized in that the insulating substrate has an inclined portion formed by slanting the end side of the insulating substrate with respect to the position where the protrusion is formed, and a common electrode is formed on this inclined portion. head. 3. The thermal printer head according to claim 1, wherein all or part of the common electrode and the individual electrodes are plated with metal. 4. The thermal printer head according to claim 1, characterized in that the longer individual electrodes have a smaller resistance value, and the shorter individual electrodes have a larger resistance value.