JPH0452056Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Field of application of invention] The present invention relates to a serial type thermal printer.

[Background of the idea]

3 and 4 show a conventional example, and FIG. 3 is a cross-sectional view showing the positional relationship between the thermal head and the platen.
FIG. 4 is an enlarged cross-sectional view of the main part.

In the drawing, 1 is a thermal head, 2 is an insulating substrate made of ceramic, 3 is an underglaze made of glass or the like, 4 is a heat generating part formed on the top of the underglaze 3, 5 is a platen, and the heat generating part 4 is connected to the platen. In order to increase the degree of adhesion of the platen 5, the insulating substrate 2 is fixed at an angle of 1 to 2 degrees with respect to the platen 5. When printing on printing paper with rough surface roughness, printing quality generally improves by increasing the supply power. In the conventional thermal printer, as shown in FIG.
The center a of the heat generating part 4 is very close to the center a of the heat generating part 4.
The platen 5 or the printing paper (not shown) wound on the platen 5 are in close contact with each other. During printing, the ink of the ink ribbon (not shown) begins to melt at the end b of the heat generating part 4, and the heat generating part 4
Ink adheres to the printing paper near the center a, and printing is performed. When the thermal head 1 moves in the direction of arrow A during the printing operation, the part between the center part a and the end part c of the heat generating part 4 passes over the already printed part of the printing paper, a of the heat generating part
The drying of the ink on the printed part of the printing paper is delayed by the residual heat generated by the area between and c, which causes the ink to penetrate into the printing paper, that is, to bleed. The drawback was that it could not be printed.

[Purpose of invention]

The present invention aims to solve the above-mentioned conventional drawbacks, and the purpose of the present invention is to suppress ink bleeding,
To provide a thermal printer that can print clearly even on printing paper with rough surface roughness.

[Summary of the idea]

In order to achieve the above object, the present invention fixes a thermal head at a predetermined angle with respect to the thermal head sliding surface of the platen during printing, and prints by moving the thermal head in the longitudinal direction of the platen. The thermal printer is characterized in that the center of pressure contact of the thermal head against the platen is located near an end of a heat generating section of the thermal head on the opposite side to the moving direction of the thermal head.

[Example of idea]

1 and 2 show an embodiment of the present invention, with FIG. 1 being a cross-sectional view showing the relationship between the thermal head and the platen, and FIG. 2 being an enlarged cross-sectional view of the main part.

In the drawing, 6 is a thermal head, 7 is an insulating substrate made of ceramic, and 8 is an underglaze made of glass or the like, which is formed on the insulating substrate 7 by firing. 9 is a heat generating part formed on the top of the underglaze 8; 10 is a platen;
The insulating substrate 7 is fixed at a predetermined angle with respect to the platen 10 in order to increase the degree of adhesion between the platen 10 and the platen 10 . And as shown in Figure 2,
One end 8a of the underglaze 8 is in contact with the tapered edge 7a of the insulating substrate 7. N is the center of pressure contact between the underglaze 8 and the platen 10, and although the center d of the heat generating part 9 and the center of pressure contact N are apart, the center N of pressure contact is located on the opposite side of the thermal head 6 in the moving direction of the heat generating part 9. It is arranged near the end e of the. 12 is an ink ribbon.

The embodiment of the present invention has the above-described structure, and during printing, first the ink on the portion 12a of the ribbon 12 facing the end f of the heat generating section 9 begins to melt, and the ribbon 12 moves and the heat generating section 9 Ink adheres to the printing paper wound around the platen 10 between the center portion d and the end portion e, and printing is performed. When the thermal head 6 moves in the direction of arrow B during the printing operation, the part of the heat generating part 9 that is removed from the end e passes over the printing paper that has already been printed, so that the ink in the printed part dries rapidly, and therefore has the effect of suppressing ink penetration into the printing paper, that is, bleeding, which conventionally occurs due to residual heat of the heat generating portion 9 and ink.

In addition, one end of the underglaze 8 is connected to the insulating substrate 7.
Since the edge 7a of the insulating substrate 7 is arranged on the edge 7a having a tapered surface, even if the pressure contact force of the thermal head 6 against the platen 10 is increased to improve printing quality, the edge 7a of the insulating substrate 7 will not come into contact with the platen 10. To prevent linear stains from occurring on the printing paper wound around the platen 10 due to friction of the edges 7a of the insulating substrate 7, and to apply a sufficient load to the heat generating part 9 of the thermal head 6 against the platen 10. This makes it possible to obtain good print quality even on printing paper with rough surface roughness.

[Effect of idea]

According to the present invention, since the center of pressure contact of the thermal head with respect to the platen is located near the end of the heat generating part of the thermal head on the opposite side to the moving direction of the thermal head, ink is generated by the residual heat of the heat generating part of the thermal head. It has the effect of suppressing bleeding and enabling clear printing even on printing paper with rough surface roughness.

[Brief explanation of the drawing]

Figures 1 and 2 show an embodiment of the present invention, with Figure 1 being a cross-sectional view, Figure 2 being an enlarged cross-sectional view of the main part, and Figures 3 and 4.
The figures show a conventional example; FIG. 3 is a cross-sectional view, and FIG. 4 is an enlarged cross-sectional view of the main part. 6...Thermal head, 7...Insulating substrate, 7a
... Edge, 8 ... Underglaze, 9 ... Heat generating part, 10 ... Platen, N ... Pressure welding center, d ...
...Central part of the heat generating part, e, f...End part of the heat generating part, 1
2... Ink ribbon.

Claims (1)

[Scope of utility model registration request] In a serial type thermal printer, in which the thermal head is fixed at an inclination of a predetermined angle with respect to the sliding surface of the thermal head of the platen during printing, and the thermal head is moved in the longitudinal direction of the platen to perform printing, the thermal head is fixed relative to the platen. A serial type thermal printer characterized in that the center of pressure contact is located near the end of the heat generating part of the thermal head on the opposite side to the moving direction of the thermal head.