JPH04332654A - Thermal printing head - Google Patents

Abstract

PURPOSE:To improve the contact properties of a heating body with an ink ribbon or beat-sensitive paper to obtain high-quality printing with a lower energy by a method wherein in a thermal printing head, the center line of the heating body is set askew in a head travel direction from a tangent line of a partially glazed glass with the ink ribbon or the heat-sensitive paper. CONSTITUTION:When a thermal printing head is mounted askew at an angle of theta deg. with respect to an ink ribbon 7 or heat-sensitive paper, a heating body 10 is formed on a position which is inclined through an angle of alpha deg. in a head travel direction from a position obtained by inclining a center line of a partially glazed glass 2 through an angle of theta deg. reversely to a head travel direction. In this manner, the contact properties of the heating body 1.0 with the ink ribbon 7 or the heat-sensitive paper are improved, and a high-quality printing free from a printing blur and the like can be obtained. In addition, the improved contact properties ensure that printing is performed with a lower energy.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal print head used in thermal printers and facsimile machines.

0002

2. Description of the Related Art A thin film thermal print head has a partially glazed glass 2 disposed on a heat-resistant insulating substrate 1 as shown in FIG. It has a structure in which a protective layer 6 is provided on the protective layer 6. When a conventional thermal print head is installed at an angle θ with respect to the ink ribbon 7 or thermal paper (paper 8 is shown in the figure), the heating element 10 is aligned with the head movement direction with respect to the center of the partially glazed glass 2. On the contrary, it was formed so that it was tilted at an angle θ. That is, the heating element 10 was formed on the intersection point A on the partially glazed glass 2, which is a tangent to the ink ribbon 7 or the thermal paper.

0003

[Problems to be Solved by the Invention] However, since the ink ribbon 7, paper 8, and platen 9 are not rigid bodies, they are squeezed by the partial glaze glass 2 due to the movement of the head, causing elastic deformation and causing the head movement of the partial glaze glass 2. Slack occurs on the direction side. Therefore, when the heating element 10 is formed on the intersection point A, the heating element 10 and the ink ribbon 7 or the thermal paper are not in optimal contact with each other, resulting in printing deterioration such as blurred printing.

An object of the present invention is to solve these conventional problems and provide a thermal print head capable of high-quality printing.

[0005]

[Means for Solving the Problems] The thermal print head of the present invention is a thermal print head in which partially glazed glass is arranged on a heat-resistant insulating substrate, and a resistive layer, an electrode layer, and a protective layer are provided thereon. , the center of the heating element,
It is characterized by being arranged at a position inclined in the head movement direction from the tangent to the ink ribbon or thermal paper on the partially glazed glass.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a structural sectional view of the vicinity of a heating element of an embodiment of a thermal print head according to the present invention. A partially glazed glass 2 is formed on a heat-resistant insulating substrate 1, and a resistive layer 3, an individual electrode layer 4, a common electrode layer 5, and a protective layer 6 are further formed on the partially glazed glass 2. In order to improve ink transferability, the thermal print head is attached at an angle θ relative to the ink ribbon 7 or thermal paper. The heating element 10 is formed at a position tilted in the head movement direction by an angle α from a position tilted at an angle θ opposite to the head movement direction with respect to the center of the partial glaze glass 2.

When actually printing using this head, for example, the printing speed is 70 cps, the pressing pressure of the head against the platen 9 is 400 g, and the dot density is 360 dpi.
Under these conditions, when the angle θ was 2°, the range of the angle α at which good printing could be obtained was 2° to 2.3°. Table 1 shows the printing results with the thermal print head we prototyped this time.
Shown below.

The optimum value of this angle α is determined by the head tilt angle θ, printing speed, head pressing pressure, etc.

[0009]

[Table 1]

[0010]Although this embodiment relates to a serial printer, it goes without saying that similar results can be obtained in a line printer as well, since the relative positional relationship between the thermal head, ink ribbon, and thermal paper remains the same. .

[0011]

[Effects of the Invention] By tilting the center position of the heating element in the direction of head movement, the positional relationship between the heating element and the ink ribbon or thermal paper is optimized, and the contact property is improved, thereby reducing printing fading, etc. It is possible to obtain high-quality printing without any blemishes. Furthermore, by improving the contact property, it becomes possible to perform printing with lower energy.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of a thermal print head of the present invention.

FIG. 2 is a sectional view of a conventional thermal print head.

[Explanation of symbols]

1 Heat-resistant insulating substrate 2 Partial glaze glass 3 Resistance layer 4 Individual electrode layer 5 Common electrode layer 6 Protective layer 7 Ink ribbon 8 Paper 9 Platen 10 Heating element A Intersection point θ on the part glaze glass when the ink ribbon is tangent Head Tilt angle α Heating element movement angle

Claims (1)

[Claims] Claim 1: In a thermal print head in which partially glazed glass is arranged on a heat-resistant insulating substrate, and a resistive layer, an electrode layer, and a protective layer are provided on top of the partially glazed glass, the center of the heating element is placed on the partially glazed glass. A thermal print head characterized by being arranged at a position tilted in the direction of head movement relative to the tangent to the ink ribbon or thermal paper.