JPS59229361A - Printing method of thermal printing head - Google Patents

Abstract

PURPOSE:To make it possible to perform printing capable of extremely reducing density irregularity and imparting high printing quality, by performing printing while reciprocating a thermal printing head at a slightly inclined angle to the surface of a platen in the moving direction side of said head. CONSTITUTION:When printing is performed to printing paper supplied between a platen 2 and a thermal printing head 3 by moving said thermal printing head 1 to the side of a forward direction, the thermal printing head 1 is inclined at an inclined angle theta of 0.5-5 deg., pref., about 2 deg. to the surface of the platen 10 in the moving direction side of said head 1. When the printing paper is printed by moving the thermal printing head 1 to the side of a backward direction, the thermal printing head 1 is inclined at an inclined angle theta' of 0.5-5 deg., pref., about 2 deg. to the surface of the platen 10 in the side of the moving direction. As a result, the thermal printing head 1 can perform printing in a uniform contact state to the printing paper during reciprocal movement.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a printing method using a serial type thermal print head that is reciprocated in a direction perpendicular to the feeding direction of printing paper.

FIG. 1 shows a conventional printing method using a thermal printing head.

The thermal printing head 1 is reciprocated parallel to the platen 2 in both the outward direction 3 and the backward direction 4.
It is designed to perform desired printing on printing paper (not shown) that is fed between the thermal printing head 1 and the platen 2. 5 is a heating element.

As shown in FIG. 2, this thermal printing head 1 is made up of an insulating base 6 provided with a chevron-shaped partial glaze 7, and further provided with the heat generating layer 5, conductor layer 8, and protective film 9. . By the way, as shown in FIG. 1, in the method of printing with the thermal print head 1, the print density on the print paper at the end of the forward path and the end of the return path of the thermal print head 1, and the print density on the print paper near the middle of the forward and return paths are determined. There is a considerable difference in density between the two, resulting in low-quality printing due to density unevenness.

This is because the thermal printing head 1 is reciprocated parallel to the two surfaces of the platen, so the state of contact between the heating element 5 and the printing paper between the two surfaces of the platen is at the end of the forward/return path and at the middle of the forward/return path. This is thought to be due to the difference between the area and the surrounding area.

SUMMARY OF THE INVENTION An object of the present invention is to improve the printing quality of a reciprocating serial type thermal printing head so that printing can be performed.

The present invention will be explained below based on the embodiment shown in FIG.

FIG. 3 shows the printing method of the thermal print head according to this embodiment, and the same reference numerals are given to the parts corresponding to those in FIG. 1. In this embodiment, when moving the thermal print head 1 in the forward direction 3 side to print on printing paper (not shown) fed between it and the platen 2, the thermal print head 1 is moved in the forward direction 3 side. A slight inclination angle θ to the platen surface 10, for example 0.5°
It is tilted with a tilt angle of ~5°, preferably about 2°.

In addition, when moving the thermal printing head 1 to the return path direction 4 side and printing on printing paper in the same manner as above, the nuclear thermal printing head 1
is similarly inclined with respect to the platen surface 10 on the moving direction side at a slight inclination angle θ', for example, 0.5° to 5°, preferably about 2°.

Therefore, in the printing method according to this embodiment, since the thermal printing head itself is always inclined with respect to the printing direction, the contact between the thermal printing head 1 and the platen surface on the printing paper at the end of the forward path and the end of the backward path. There is no big difference between the state and that near the middle of the outbound and return trips. Therefore, the thermal print head 1 is able to print in a uniform state of contact with the print paper on all forward and return paths, and as a result, it is possible to print with high print quality with extremely little density unevenness. becomes possible.

As described above, according to the present invention, printing is performed by reciprocating the thermal print head at a slight inclination angle with respect to the platen surface on the side of the movement direction, so that the printing by the thermal print head is The state of contact with the paper can be made good and almost uniform over the entire forward and backward paths, and therefore printing can be performed with high print quality.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a conventional printing method, FIG. 2 is a sectional view of a thermal printing head, and FIG. 3 is a diagram showing a printing method according to an embodiment of the present invention. 1.Thermal print head, 2.Platen, 3.Outward direction, 4.Return direction, 5.Heating element, θ, θ'.Inclination angle. Applicant: ROHM Co., Ltd. Agent: Kazuhide Okada, patent attorney

Claims (1)

[Claims] (1) In a printing method using a thermal print head that moves back and forth in a direction perpendicular to the printing paper feeding direction, the thermal print head is
A printing method using a thermal print head that prints by moving it back and forth at a slight angle of inclination to the platen surface in the direction of movement.