JPH04366648A - Structure of thermal head - Google Patents

Abstract

PURPOSE:To reduce the number of component parts to reduce a machining manhour and an assembling manhour by a method wherein a substrate base is provided with a tip end part opposed to a surface of an alumina substrate fixed on a flat part of the substrate with a gap for clamping a flexible substrate with the surface of the alumina substrate. CONSTITUTION:An alumina substrate 1 is fixed on a flat part 201 of a substrate base 20. A flexible substrate 5 is mounted so as to be held between the tip end of a flexible substrate fixing part 202 and the surface of the alumina substrate 1 and curved along the surface of the flexible substrate fixing part 202. On an electrode on the alumina substrate 1, an electrode on the flexible substrate 5 corresponding to the electrode is depressed by the bending stress of the flexible substrate 5, whereby the electrode on the alumina substrate 1 is connected to the external through the electrode on the flexible substrate 5. In this structure of a thermal head, the number of component parts can be reduced, and the need for machining a tapped hole and uniformly fastening a presser fitting with a screw is eliminated. A manhour can be reduced, and a cost can be lowered.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the structure of a thermal head used in a thermal recording device.

0002

2. Description of the Related Art FIG. 4 is a perspective view showing a schematic structure of an example of a thermal head used in a conventional thermal recording device, and FIG. 5 is a side view showing a detailed structure of a portion A in FIG. , 1 is an alumina substrate, a thermal head array 11 consisting of a plurality of heating resistors, a control circuit (not shown) for selecting an arbitrary heating resistor from the thermal head array 11 according to an external signal, and Electrodes (not shown) for supplying external power to each heating resistor, electrodes (not shown) for connecting the control circuit and external circuit (
(not shown) etc. are provided. 2 is a substrate base, 3 is a holding fitting, 4 is a screw, 5 is a flexible substrate, 6 is a support plate, and 7 is silicon rubber.

[0003] The electrodes disposed on the alumina substrate 1 are partially fastened and fixed to the substrate base 2 by a presser metal fitting 3, and are disposed on a flexible substrate 5 which is press-welded to the alumina substrate 1 via a silicone rubber 7. When a signal is sent from the external circuit through the flexible substrate 5, the control circuit selects the heating resistor indicated by the signal from the thermal head array 11, and selects the heating resistor from the thermal head array 11. The grounding conductor of the heating resistor is grounded, and current is supplied from an external power supply to the thermal head array 11.
A predetermined portion of the thermal head array 11 is heated.
Recording is performed on thermal paper that is fed out while being in contact with the paper.

0004

[Problem to be Solved by the Invention] The problem to be solved is that in the structure of the conventional thermal head as described above,
The problem is that it requires a large number of parts and man-hours, resulting in high costs. That is, in addition to the alumina substrate 1, the substrate base 2, and the flexible substrate 5, the flexible substrate 5 is connected to the substrate base 2.
In order to fix it to the alumina substrate 1 and press it to the alumina substrate 1, it is necessary to use the presser metal fitting 3, the screw 4, and the silicone rubber 7, which increases the number of component parts. Furthermore, in order to ensure complete pressure contact of the flexible substrate 5 to the alumina substrate 1, a large number of screws are required, and for one screw 4, screw holes are required in each of the holding fitting 3, the flexible substrate 5, and the substrate base 2. It is necessary to drill the screw hole, and the man-hours required for drilling the screw hole and the man-hours required for tightening the screw become high. In addition, in the conventional structure, the alumina substrate 1 is held down by the silicone rubber 7, so the contact surface is large, and when expansion due to heat occurs, it cannot move freely, causing problems such as thermal warping. .

[0005] The present invention has been made to solve these problems, and aims to provide a thermal head structure that has a small number of component parts, can reduce the number of processing steps and assembly steps, and can be manufactured at low cost.

[0006]

[Means for Solving the Problems] The structure of the thermal head according to the present invention is such that the thermal head is integrally attached to a flat plate portion of a substrate base to which an alumina substrate is fixed, and the surface of the alumina substrate is placed opposite to the surface of the alumina substrate fixed to the flat plate portion. A flexible substrate fixing section is provided with a tip portion having a gap between which the flexible substrate can be sandwiched and held, and the flexible substrate is connected between the tip portion of the flexible substrate fixing section and the surface of the alumina substrate fixed to the flat plate section. The flexible substrate is held in between and bent along the surface of the flexible substrate fixing part to attach it, and the electrode of the flexible substrate corresponding to the electrode of the alumina substrate is pressed against the electrode of the alumina substrate by the bending stress of the flexible substrate.

[0007]

[Function] By adopting the above structure, the presser fitting, screws, and silicone rubber can be eliminated, the number of component parts can be reduced, and the number of man-hours required for screw hole drilling and screw tightening can be reduced.

[0008]

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a side view showing one embodiment of the present invention. In the figure, 1 and 5 indicate the same or equivalent parts as the same reference numerals in FIG. The flexible substrate 201 and the tip portion integrally provided on the flat plate portion 201 face the surface of the alumina substrate 1, and have a gap between the tip portion and the surface of the alumina substrate 1 to sandwich and hold the flexible substrate 5. A board fixing section 202 is provided.

The alumina substrate 1 is fixed to the flat plate portion 201 of the substrate base 20, and the flexible substrate 5 is connected to the tip of the flexible substrate fixing portion 202 and the alumina substrate 1.
The electrodes of the flexible substrate 5 corresponding to the electrodes of the alumina substrate 1 are attached to the electrodes of the alumina substrate 1 by the bending of the flexible substrate 5. They are pressed together by stress, and the electrodes of the alumina substrate 1 are connected to the outside via the electrodes of the flexible substrate 5.

FIGS. 2 and 3 are side views showing other embodiments of the present invention. In the figures, the same reference numerals as in FIG. 1 indicate the same or equivalent parts, 8 is a rubber sheet, 9 is silicone rubber be. With the structure shown in FIGS. 2 and 3, better contact can be obtained between the electrodes of the flexible substrate 5 and the electrodes of the alumina substrate 1 due to the elasticity of the rubber sheet 8 or silicone rubber 9. Become.

[0011]

[Effects of the Invention] As explained above, the structure of the thermal head of the present invention reduces the number of component parts, eliminates the need for threaded hole drilling and uniform tightening of the presser fitting with screws, and reduces man-hours and costs. Good electrode contact can be obtained over the entire length of the flexible substrate, and since the alumina substrate is inserted into the flexible substrate for easy movement, thermal warping due to thermal expansion can be prevented.

[Brief explanation of drawings]

FIG. 1 is a side view showing one embodiment of the present invention.

FIG. 2 is a side view showing another embodiment of the invention.

FIG. 3 is a side view showing another embodiment of the present invention.

FIG. 4 is a perspective view showing a schematic structure of an example of a conventional thermal head.

FIG. 5 is a side view showing the detailed structure of the portion A in FIG. 4;

[Explanation of symbols]

1 Alumina substrate 5 Flexible board 8 Rubber sheet 9 Silicone rubber 20 Board base 201 Flat plate part 202 Flexible board fixing part

Claims (1)

[Claims] 1. A thermal head array consisting of a plurality of heat generating resistors, a control circuit that selects any heat generating resistor from the thermal head array in response to an external signal, and an external power source for each heat generating resistor in the thermal head array. An alumina substrate is fixed to the substrate base, and the electrodes arranged on the alumina substrate are arranged on a flexible substrate. In the structure of a thermal head connected to an external circuit through an electrode, the substrate base has a flat plate portion fixing an alumina substrate, and a surface of the alumina substrate that faces the surface of the alumina substrate fixed to the flat plate portion. and a flexible board fixing part integrally provided with the flat plate part, the flexible board having a tip part having a gap that can hold the flexible board in between, and the flexible board being fixed to the tip part of the flexible board fixing part and the flat plate part. By being held between the surfaces of the alumina substrate and bent and attached along the surface of the flexible substrate fixing part, the electrodes of the flexible substrate corresponding to the electrodes of the alumina substrate are attached to the flexible substrate. A thermal head structure characterized by pressure welding due to bending stress.