JPS6189873A - Thermal recording head - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is applicable to small serial type printers mounted on calculators, etc., medium sized serial type printers compatible with hand belt computers, etc., and serial type printers that require high print quality. The present invention relates to a serial type thermal recording head used in thermal or thermal transfer recording devices such as large printers.

Conventional configuration and its problems In recent years, with the development of office automation.

Demand for recording devices using thermal recording heads, which are characterized by low noise and high print quality, is increasing, but the following problems arising from the heat generation characteristics hinder the achievement of clear and high quality print quality. It was getting worse.

A conventional thermal recording head will be explained with reference to FIGS. 4 to 7. FIG. 4 is a perspective view of a conventional thermal recording head, and FIG. 5 is an enlarged plan view of its heating element section, in which (1) is a thermal recording head, (la) is a ceramic substrate, (Ib
) is the glaze layer on which heating elements are formed, and (1c) is the lead from each heating element resistor.

(ld) is a conductive contact portion with the flexible pattern cable, and this conductive contact portion (1d) is normally
Gold plated or solder plated. As shown in FIG. 5, all the heating elements have a length of m and a width of m. In the thermal recording head (1) having such a shape, when all the dots are colored, as shown in FIG. The shape of the colored dot is equal to or larger than the shape of the heating element, and the other colored dots, especially the uppermost and lowest colored dots, are colored dots of a size smaller than or equal to the shape of the head heating element, and all dots are colored. (The line feed pitch is equal to the number of colored dots.) When this operation is performed, there appears to be a gap between the bands as shown in FIG. 6(B). In addition, Fig. 7 (A) (B
) When printing an English character such as riJ, the "°" at the top is difficult to see because the one-colored dot is too small, and it may look like a "1".

Therefore, the following methods have been considered as ways to deal with the above problems. First, regarding the problem that the colored dots at the top and bottom are small.

One method is to locally increase the voltage applied to the head or the width of the pulse applied to the method, and one method to solve the problem of gaps is to intentionally reduce the line feed pitch. However, all of these solutions have drawbacks. In other words, in order to control the voltage applied to the head and the pulse width, it is necessary to add a hardware circuit or add memory to establish a software algorithm, which increases the cost. Formal line break pitch (for example, inch system l/6°1/
8-inch line breaks, etc.) cannot be guaranteed, resulting in irregular line breaks.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned conventional drawbacks, and an object thereof is to provide a thermal recording head that can equalize the area of all colored dots without correction using complicated circuits or software. do.

In order to achieve the object described in item 1 of ``Structure of the Invention'', the thermal recording head of the present invention has a structure in which the area of at least the uppermost and lowest heating elements is increased so that the areas of colored dots formed by all the heating elements are made uniform. It has a configuration that is larger than other heating elements.

According to this configuration, it is possible to realize the area of all colored dots, etc. without correction using complicated circuits or correction using software.

DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to the drawings.6 FIG. 5 is a plan view of a heating element portion of a thermal recording head in an embodiment of the present invention. The configuration other than this heating element portion is the same as the conventional example shown in FIG. The heating elements at the top ■ and the bottom ■ are larger than the other heating elements (in this example, they are 20% larger both vertically and horizontally), and their resistance values are the same as the other heating elements. Therefore, the colored dots become as shown in Figures 2 and 3, and even when all dots are colored, the colored dots at the third and lowest positions are much different from the densely populated area near the center. Without,
Even if all dots are colored continuously, no gaps will be visible between each row as shown in FIG. 2(B).

Furthermore, even when an English letter such as "i" is printed as shown in FIGS. 3(A) and 3(B), the uppermost dot "°" is clearly printed.

In the above example, only the areas of the top and bottom heating elements were made different from the others, but it may be possible to make all colored dots more equal in area, or when the number of dots is as large as 16 or 36 dots. For this purpose, the area of the heating element may be divided into several stages such that both ends become larger.

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, at least the areas of the uppermost and lowest heating elements are made larger than other heating elements so that the areas of all colored dots are equalized. By simply applying the same amount of energy (head applied voltage or pulse width, etc.) to the heating element, problems such as gaps between lines and blurred top dots can be solved, and the entire recording device can be saved without any hardware or software cost increases. It is possible to realize cost reduction and miniaturization.

[Brief explanation of drawings]

FIG. 1 is a plan view of the heating element section of a thermal recording head according to an embodiment of the present invention, FIGS. 2 and 3 are explanatory diagrams of printing results by the same thermal recording head, and FIG. A perspective view of a conventional thermal recording head, FIG. 5 is an enlarged plan view of a heating element portion of the thermal recording head, and FIGS. 6 and 7 are explanatory diagrams of the printed result I by the thermal recording head, respectively. It is. (1) Thermal recording head, (1b) Glaze layer agent Yoshihiro Morimoto Figure 1 Figure 2 Section 3 (1:4) (A) Figure 4! Figure 6 Figure 6 Figure 7 (A) (A)

Claims (1)

[Claims] 1. A thermal recording head in which the areas of at least the uppermost and lowest heating elements are larger than the other heating elements so that the areas of colored dots produced by all heating elements are made uniform.