JPH0611797Y2 - Thick film thermal head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a thermal recording device such as a facsimile or a printer,
The present invention relates to a thick film type thermal head used in a thermal transfer recording apparatus.

[Conventional technology]

Generally, as shown in FIG. 3, a thermal transfer recording apparatus is provided with a thermal head 1 which internally has a heating resistor that selectively generates heat according to recorded image information, and is arranged in pressure contact with the thermal head 1. A recording unit 3 including an outer peripheral surface coated with a back roll 2 coated with an elastic material such as silicone rubber is provided, and a recording sheet 4 such as plain paper is provided on the recording unit 3 and an ink having a heat-sensitive ink layer formed on one surface thereof. The donor sheet 5 is superposed and fed by rollers 6 and 7, and the thermal head 1 selectively melts or sublimates the heat-sensitive ink layer of the ink donor sheet 5, and transfers this onto the recording sheet 4 to transfer heat. This is a recording device. The thermal head 1 is generally configured by forming a pair of electrodes on an insulating substrate by a thin film or thick film technique and connecting a heating resistor between the electrodes, and using a heating resistor between the electrodes. Electric power is applied to heat the heating resistor by Joule heat.

The conventional thick film thermal head 1 will be described with reference to FIG. 4. A glass layer 9 is coated on an alumina substrate 8 by a thick film technique, and a conductive paste containing Au is used on the glass layer 9.
The common and individual electrode conductors 10 are formed by firing at a temperature near 00 ° C., metallizing, and patterning using a photolithography technique. Next, after using a resistive paste containing ruthenium oxide and firing it at a temperature near 900 ° C. to form the heat generating resistor 11, the abrasion resistant layer 12 is formed with 9
Thick film type thermal head 1 fired at a temperature of around 00 ° C
Is formed.

[Problems to be solved by the invention]

Conventionally, in order to reduce the cost of heat-sensitive recording, fax, printer, etc. using heat-sensitive transfer recording, the power consumption of the power supply and the print head are largely restricted. To improve this, there is a need to reduce the power consumption of the print head. Is increasing.

By the way, when forming the thermal head with thick film technology, in order to print at lower power consumption and higher speed, the shape of the heating resistor should be reduced to reduce the heat capacity or the effect of heat escape should be recorded. It is necessary to increase the heat generation efficiency, for example, by suppressing it so that it does not trail on paper. However, when the shape of the heating resistor is made small, there is a problem that the power resistance characteristic of the heating resistor is deteriorated substantially in proportion. Further, in the conventional thick film technology, the width is about 10
The limit is 0 μm and the film thickness is about 10 μm. If such a small heating resistor is formed, the smaller the heating resistor is, the larger the variation in the resistance value that greatly contributes to the shape of the heating resistor is. Has the problem of becoming.

In addition, as shown in FIG. 4 (b), the heat escape of the thermal head is caused by the heating resistor 11 to the glass layer 9 and the electrode 1.
Since it is considered that the escape to 0 is large (about 40% each), measures such as thinning the film thickness of the electrode 10, using a material that lowers the thermal conductivity of the glass layer 9, or increasing the film thickness are taken. Has been done. However, with the materials currently on the market, the film thickness of the electrode 10 can be reduced only to about 1.0 μm due to the film quality, the yield in production, etc. There is a problem that the thermal conductivity is limited in terms of material.

The present invention solves the above-mentioned conventional problems, and provides a thick film type thermal head capable of enlarging the shape of a heating resistor, improving heat generation efficiency, and not deteriorating power withstanding characteristics. With the goal.

[Means for solving problems]

Therefore, the thick film type thermal head of the present invention comprises a plurality of electrode conductors formed on a glass-coated insulating substrate,
A heating resistor formed on the plurality of electrode conductors,
In the thick-film thermal head that heats the heating resistor between the electrodes by passing a current between the adjacent electrodes of the plurality of electrode conductors, the current between the heating resistor on the electrode conductor The glass layer is provided in the direction.

[Action]

In the present invention, for example, as shown in FIG. 1, by forming the glass layer 13 made of a material having a high heat storage property,
Even if it has a shape larger than that of the conventional heating resistor, the escape to the electrodes is blocked and the glass layer 13 itself has a heat storage property.
The thermal efficiency is improved, and a print density equal to or higher than the conventional one or even with low energy can be secured.

〔Example〕

 Embodiments will be described below with reference to the drawings.

FIG. 1 (a) is a sectional view showing one embodiment of the thick film type thermal head of the present invention, FIG. 1 (b) is a plan view thereof, and FIG. 2 (a) is a thick film type thermal head of the present invention. Sectional drawing which shows another Example, and the same figure (b) is the top view. 8 in the figure
Is an insulating substrate, 9 is a glass layer, 10 is an electrode conductor, 11 is a heating resistor, 12 is a wear resistant layer, and 13 and 14 are glass layers having a high heat storage property.

In FIG. 1, the thick film type thermal head of the present invention has a feature that it can be manufactured by the same thick film technology as the conventional manufacturing method described in FIG. 4, and is different from the conventional manufacturing method. The point to do is the alumina substrate 8 coated with the glass layer 9.
After forming the electrode conductor 10 on the top, using a thick film technique, a width of about 1
The point is that the glass layer 13 made of a material having a high heat storage property of 00 μm to 130 μm and a thickness of about 15 μm is fired at a temperature near 900 ° C., and then the heating resistor 11 is formed.

That is, the plurality of electrode conductors 10 and the plurality of electrode conductors 10
A thick film type thermal head which has a heating resistor 11 formed on it, and causes a heating resistor between the electrodes to generate heat by causing a current to flow between adjacent electrodes of the plurality of electrode conductors 10. By forming the glass layer 13 between the heating resistor 11 on the conductor 10 in the direction of the current, even if the glass layer 13 has a larger shape than the conventional heating resistor,
Since the escape to the electrode is blocked and the heat storage property of the glass layer 13 itself improves the thermal efficiency, it is possible to secure a print density equal to or higher than the conventional one or even with low energy. Also in terms of power resistance characteristics, since the shape of the heating resistor can be increased with the same print density as the conventional one, it is possible to improve the power resistance characteristics as well.
It is also possible to reduce variations in resistance value due to the large number of shapes.

Next, another embodiment of the present invention will be described with reference to FIG. 2. In this embodiment, after the electrode 10 is formed on the alumina substrate 8 coated with the glass layer 9, both sides of the lower surface of the heating resistor 11 are formed. By forming two parallel glass layers 14, 14 in the longitudinal direction at the corresponding portions, the heating resistor 1
The current distribution of No. 1 can be concentrated in the central portion of the heating resistor 11, the thermal efficiency can be further improved, and the contact cross-sectional area with the electrode is also reduced, so that the prevention of heat escape is improved. be able to.

The present invention is not limited to the above embodiment, and it goes without saying that various modifications can be made. For example, by polishing the surfaces of the glass layers 13 and 14 having high heat storage properties in the above-described examples, the surface properties of the glass layers are improved, and the unevenness of the glass layers under the heating resistor 11 is reduced to reduce the resistance value. Variations can be reduced.

[Effect of device]

As described above, according to the present invention, even if it has a larger shape than the conventional heating resistor, the escape to the electrode is blocked, and the heat storage property of the glass layer 13 itself improves the thermal efficiency. Even if the energy is the same or low, the same or higher print density can be secured.

Also, in terms of power resistance characteristics, since the shape of the heating resistor can be enlarged at the same print density as the conventional one,
It is possible to improve the withstand power characteristics as well as reduce the variation in the resistance value due to the large number of shapes.

[Brief description of drawings]

FIG. 1 (a) is a sectional view showing one embodiment of the thick film type thermal head of the present invention, FIG. 1 (b) is a plan view thereof, and FIG. 2 (a) is a thick film type thermal head of the present invention. FIG. 4B is a cross-sectional view showing another embodiment, FIG. 3B is a plan view thereof, FIG. 3 is a schematic view of a thermal transfer recording apparatus, and FIG. 4A is a cross-sectional view showing a conventional thick film type thermal head. FIG. 2B is a plan view thereof. 8 ... Insulating substrate, 9 ... Glass layer, 10 ... Electrode conductor, 11 ... Heating resistor, 12 ... Wear resistant layer, 13, 1
4 ... A glass layer having a high heat storage property.

Claims (2)

[Scope of utility model registration request] 1. A plurality of electrode conductors formed on a glass-coated insulating substrate, and a heating resistor formed on the plurality of electrode conductors, and adjacent electrodes among the plurality of electrode conductors. In a thick film type thermal head that causes a heating resistor between electrodes to generate heat by passing a current between them, a glass layer is provided between the heating resistor on the electrode conductor and in the direction of the current. Thick film type thermal head. 2. The thick film type thermal head according to claim 1, wherein the glass layer is made of a material having a high heat storage property.