JPS61202856A - Thermal head - Google Patents

Abstract

PURPOSE:To eliminate the generation of fouled printing and obtain high printing quality and high printing speed by providing a larger angle formed by a tangent connecting the surface of a thermal head to the outline edge of a chip from a partial glazed layer top compared to the angle of a thermal head attached to a thermal printer in an inclined manner. CONSTITUTION:A distance C between a partial glazed layer and an outline edge of a chip is scaled down so that the outline edge of a thermal head does not contact a thermal recorder. The gradient angle of a thermal head attached to a thermal printer 15 is set at 2 deg., and the angle theta deg. of the size A/C of an insulative substrate 1 and the partial glazed layer 2 is set about 1 deg. larger than the gradient angle 2 deg. of the thermal head 11. For this reason, the C size will be sufficiently short and the partial glazed layer 2 be formed justified to an outline edge (c) point of a chip.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention mainly relates to a thermal head used in a printer of a thermal transfer section.

[Prior art and its problems]

Conventionally, for example, a plurality of heating resistor elements are linearly arranged on a partial glaze of the same substrate, and according to information, the heating resistor elements are heated with electricity to record nine colors on thermal recording paper or ink ribbon. A thermal head is used to transfer and record onto plain paper via a .

A conventional thermal head will be explained using FIGS. 3 and 4. Parting lines 6 are formed in a grid pattern on the insulating substrate 1, and a glaze layer 2 made of glass is partially formed near the parting line 6 (hereinafter referred to as partial glaze layer 2).Partial glaze layer 2 is made of glass. By screen printing the paste and firing it, the cross section is formed into a semicircular arc shape. Generally, those having a thickness of 30 to 60 μm in human size are used. A power supply layer 4 is provided on top of the partial glaze layer 2 with a plurality of heating resistor layers 3 arranged in a straight line, and is covered with a protective layer 5 to prevent damage due to oxidation and wear. 1 thermal head like this
Generally, a large number of thermal heads are formed simultaneously on a single insulating substrate 1, and are divided into respective thermal heads in the final manufacturing process. The dividing method at this time is to use a laser beam to divide the front or back surface of the insulating substrate 1 in advance along a division line 6 in which perforations are formed in a lattice shape, which is economical and generally practiced. However, the external edges of the thermal head divided by this processing method are very sharp and have the characteristic of being cutler-like.

In addition, a partial glaze layer 2 is included in the thermal head.
is formed by printing and firing a thick film using glass paste, and then 30 to 6
In order to ensure a thickness of 0 μm, the practical limit for the width B of the partial glaze layer 2 is about 9.7 mm when the thickness of dimension A is 40 μm, for example, due to the surface tension of glass and wettability with alumina.

In addition, when firing, the partial glaze layer 2 becomes molten and flows due to surface tension, and when the cross-sectional shape becomes a semicircular arc, it has the property of expanding with Kfi, and considering the variation in positioning accuracy during printing, it is insulated. The distance C between the centers of the dividing line 6 of the transparent substrate IK and the partial glaze layer 2 is about Q, and the practical limit is 5 mm. However, in conventional commercially available thermal heads, the width dimension B of the partial glaze layer 20 is Q, 7 mm or more, and the partial glaze layer 2 and the dividing line 6
The center-to-center distance C dimension is 1 mm or more.

In recent years, the market for day-to-day typewriters and word processors using thermal transfer printers has been expanding, and as a result, there is a strong demand for high print quality regardless of paper quality. As shown in FIG. 5, a conventional thermal head 11 is used to increase the pressure contact force with the platen 13 and the thermal recording medium 14, and in particular, when the head 11 is attached to the Φ rim 12, the head 11 is attached to the φ edge 12, and when Attempts have been made to create a tilt angle to equalize the pressure distribution on the thermal recording medium 14, and have achieved success. For example, when the inclination angle of the thermal head 11 of a thermal printer is set to 2 degrees and the thermal head 11 prints in sliding contact with the thermal recording medium 14, the pressure distribution becomes more uniform, and especially in thermal transfer WVC using an ink ribbon, the density is uniform. It was found that high print quality could be obtained.

However, when using the conventional thermal head shown in FIGS. 3 and 4, the C dimension from the dividing line 6 of the thermal head to the center of the partial glaze layer 2 is large, 1 mm or more.
When the thermal head is attached to the printer at an angle for printing, the outer edge lla of the thermal head is aligned with the thermal recording medium 1 as shown in Fig. 5.
4, the edge of the divided chip is very sharp as described above, and the edge is made of a hard material, so when it comes into sliding contact, the thermal recording medium 14 is scraped, producing powder and causing printing stains. . Also, with a commercially available thermal head,
The one with the smallest dimension of 1 mm, partial glaze layer 2 is 4
For a product with a thickness of 0 μm, the calculated allowable inclination angle is 2°.
18', and it seems that it can be used for the inclination angle 26 of the thermal head 11 mounted on the carriage 12 of the printer 15, but in reality, printing stains occur frequently. The thermal head 11 relative to the platen 13 of the printer 15 in %
If pressure is applied or released with a shocking action, the striking lines will appear as stains on the recording paper. This is because the platen 13 is made of rubber and is concave due to the pressure contact force, and the outer edge 11a is in contact with the platen 13. Next, when the temperature of the printer 150 becomes high, the ink on the ink ribbon is easily transferred even by slight pressure contact, so sliding contact between the outer edge lla of the thermal plate 11 and the ink ribbon must be avoided. As described above, even if the conventional thermal head 11 is attached to the printer 15 at an angle to equalize the pressure distribution during the printing process and to obtain high printing quality, there is a serious problem in that the problem of print smudge increases.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned problems of the prior art, and it is an object of the present invention that the angle formed by the bonding edge connecting the surface of the thermal head and the top of the partial glaze layer to the edge of the chip outer shape is inclined in a thermal printer. At an angle of 2°
In order to achieve a sufficiently large size, the present invention is to provide a thermal head that eliminates the occurrence of printing stains without changing the conventional processing method of the thermal head, and that enables high printing quality and high speed.

[Summary of the invention]

To achieve this purpose, a partial glaze layer with a semicircular arc cross section is formed on the insulating base, a plurality of heating resistor layers are arranged linearly on top of the partial glaze layer, and power is supplied to the heating resistor layer. In a thermal five-piece comprising a power supply layer and a protective layer formed on the power supply layer, a floating portion of a partial glaze layer forming the heating resistor layer, and a top portion of the partial glaze layer; Mainly from the center of the partial glaze layer to the edge of the chip outer shape so that the angle of the triangle formed by the tangent line connecting the outer edge of the chip is sufficiently larger than the 2° inclination angle of the thermal head attached to the printer. C
It is characterized by reduced dimensions.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

The cross-sectional configuration of the thermal head is the same as the conventional one.

The difference is that the distance C dimension between the partial glaze layer and the chip outer edge is reduced, and the same elements as in the prior art are given the same reference numerals.

FIG. 1 is a diagram showing the relative relationship between an insulating substrate 1 and a partial glaze layer 2. As shown in FIG. Point a is the intersection of the center line of the partial glaze layer 2 and the insulating substrate 1. The point is the apex on the center line of the partial glaze layer 2. Point C is an intersection on a tangent line connecting the apex a of the partial glaze layer 20 to the outer edge of the insulating substrate 1. The thickness of the glaze between points a and b, which connect the above three points, is defined as human. Also, let C be the dimension from the partial glaze layer to the outer edge between points a and C. In such a triangle, the angle formed by sides a-C and sides b-c is 0.
Set it to 0. Here, this angle θ0 is tanθ0=side a~b
/ It is the one that is made by sides a-C.

Next, FIG. 2 is a partial view of the thermal head of the present invention installed in a thermal printer at an angle, and the configuration is exactly the same as the conventional one. The difference is that the distance C between the partial glaze layer and the outer edge of the chip is reduced to prevent the outer edge of the thermal head from coming into contact with the thermal recording medium.Elements that are the same as before are indicated by the same reference numerals. . Experiments have shown that when the inclination angle of the thermal head 11 attached to the thermal printer 15 is set to 2 degrees, the pressure distribution in the printing area 11 becomes almost optimal and a uniform density can be obtained. Regarding the dimensions of No. 11 and the occurrence of printing stains, the results are shown below.

~ From Table 1, by setting the angle θ0 approximately 1' larger from the relationship between the angle θ0 in dimensions A/C and the printing dirt, [
It was found that printing stains can be sufficiently prevented. As described above, the angle θ° between the insulating substrate 1 and the partial glaze layer 20 dimension A/C is the thermal head 1 of the thermal printer 15.
The purpose can be achieved by increasing P11° for an inclination angle of 2°.

To do this, make the C dimension shown in the wt1 diagram sufficiently short,
The partial glaze layer 2 is formed so as to be biased toward the edge C of the chip. By doing this, even if the external edge lla of the thermal head 11 shown in FIG. 15, even if the thermal head 11 presses and releases with impact, the thermal recording medium 14 is not strongly pressed, resulting in a feature that no printing stains occur at all.

〔Effect of the invention〕

As explained above, according to the thermal head according to the present invention, the partial glaze layer is formed sufficiently offset to the chip outer edge. Even if an angle of inclination is given, the external edge of the thermal head does not come into pressure contact with the thermal recording medium, so there is no need to worry about print stains.The thermal head forms a uniform and efficient pressure distribution during the printing process, and as a result The heat conduction efficiency to the recording medium is uniform and efficient, making it suitable for high print quality and high speed printers.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing the relative relationship between the insulating substrate and the partial glaze layer that constitute the thermal head of the present invention, and FIG. 2 is a cross-sectional view showing the sliding contact mode in the printing section of a printer equipped with the thermal head of the present invention. Figure, I! Figure 3 is a cross-sectional view showing the structure of a conventional thermal head, Figure 4 is a partial plan view showing the relationship between the partial glaze layer and dividing line of the conventional thermal head, and Figure 5 is a printer equipped with the conventional thermal head. FIG. 3 is a cross-sectional view showing a sliding contact mode in a printed portion of the invention. DESCRIPTION OF SYMBOLS 1... Insulating substrate, 2... Partial glaze layer, 11... Thermal head, 11a...
...Outline edge, 12...Carriage, 13
...Platen, 14...Thermal recording medium〇Figure 3 Date Figure 4

Claims (1)

[Claims] A partial glaze layer with a semicircular arc cross section is formed on an insulating substrate, a plurality of heat generating resistor layers are linearly arranged approximately at the top of the partial glaze layer, and power is supplied to the heat generating resistor layer. In a thermal head including a power supply layer and a protective layer formed on the power supply layer, the thickness of the partial glaze layer in which the heating resistor layer is arranged, the top of the partial glaze layer, and the external edge of the chip. A thermal head characterized in that the tan angle of the triangle formed by the tangent line between the two is in the range of 3 to 5 degrees.