JP2959876B2 - Thermal head structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[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 apparatus, and FIG. 5 is a side view showing a detailed structure of a portion A in FIG. Reference numeral 1 denotes an alumina substrate, a thermal head array 11 including a plurality of heating resistors, a control circuit (not shown) for selecting an arbitrary heating resistor from the thermal head array 11 based on an external signal, and a thermal head array 11. An electrode (not shown) for supplying external power to each heating resistor, an electrode (not shown) for connecting a control circuit to an external circuit, and the like are provided. 2 is the substrate base, 3
Reference numeral 4 denotes a screw, reference numeral 4 denotes a screw, reference numeral 5 denotes a flexible substrate, reference numeral 6 denotes a support plate, and reference numeral 7 denotes silicon rubber.

[0003] The electrodes disposed on the alumina substrate 1 are partially fixed to the substrate base 2 by means of a holding metal 3 and are disposed on a flexible substrate 5 pressed against the alumina substrate 1 via a silicon rubber 7. When a signal is sent from the external circuit via the flexible substrate 5 to the external circuit, the heating circuit indicated by the signal is selected from the thermal head array 11 by the control circuit. The ground-side conductor of the heating resistor is grounded, and a current is supplied from an external power supply to the thermal head array 11.
Of the thermal head array 11 is heated.
The recording is performed on the thermal paper that is sent out while contacting the paper.

[0004]

The problem to be solved is that the structure of the conventional thermal head as described above,
The number of parts and man-hours are large and the cost is high. That is, in addition to the alumina substrate 1, the substrate base 2, and the flexible substrate 5, the presser fitting 3 is used for fixing the flexible substrate 5 to the substrate base 2 and pressing the flexible substrate 5 against the alumina substrate 1.
, Screws 4 and silicon rubber 7 must be used, which increases the number of components. Also, a large number of screws are required to secure the complete press-contact of the flexible substrate 5 to the alumina substrate 1, and each of the screws 4 has a holding hole 3, a flexible substrate 5, and a screw hole in the substrate base 2. In this case, the number of steps required to form the screw hole and the number of steps required to tighten the screw are required, which increases the cost. Further, in the conventional structure, since the alumina substrate 1 is held down by the silicon rubber 7, there is a problem that the contact surface is large, and if the expansion occurs due to heat, it cannot move freely, and thermal warpage occurs. .

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has as its object to provide a thermal head structure which can be manufactured at a low cost with a reduced number of components, a reduced number of processing steps and assembly steps.

[0006]

The structure of the thermal head according to the present invention is such that the surface of the alumina substrate fixed to the flat plate portion is integrally formed on the surface of the alumina substrate fixed to the flat plate portion. A flexible substrate fixing portion having a tip portion having a gap capable of holding the flexible substrate therebetween is provided between the flexible substrate fixing portion and the alumina substrate surface fixed to the flat plate portion. It is characterized in that it is sandwiched and held, bent and attached along the surface of the flexible substrate fixing portion, and the electrode of the flexible substrate corresponding to the electrode is pressed against the electrode of the alumina substrate by the bending stress of the flexible substrate.

[0007]

The above structure eliminates the need for a holding bracket, a screw, and silicone rubber, thereby reducing the number of components and the number of steps required for drilling and tightening a screw.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side view showing an embodiment of the present invention. In the drawings, reference numerals 1 and 5 denote the same or corresponding components as those in FIG. 5, and reference numeral 20 denotes a substrate base, which is a flat plate for fixing an alumina substrate 1. The portion 201 and a front end portion provided integrally with the flat plate portion 201 face the surface of the alumina substrate 1 and have a gap between the front end portion and the surface of the alumina substrate 1 that can hold the flexible substrate 5 therebetween. A substrate fixing part 202 is provided.

Then, 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 distal end portion of the flexible substrate fixing portion 202 by the alumina substrate 1.
Are held between the surfaces of the flexible substrate fixing portion 202, and are bent along the surface of the flexible substrate fixing portion 202. The electrodes of the flexible substrate 5 corresponding to the electrodes are attached to the electrodes of the alumina substrate 1. The electrodes of the alumina substrate 1 are pressed against each other by the stress and are connected to the outside via the electrodes of the flexible substrate 5.

FIGS. 2 and 3 are side views showing another embodiment of the present invention. In the figures, the same reference numerals as those in FIG. 1 denote the same or corresponding elements, 8 denotes a rubber sheet, and 9 denotes silicone rubber. is there. With the structure shown in FIGS. 2 and 3, better contact between the electrode of the flexible substrate 5 and the electrode of the alumina substrate 1 can be obtained by the elasticity of the rubber sheet 8 or the silicon rubber 9. Become.

[0011]

As described above, the structure of the thermal head according to the present invention can reduce the number of components and eliminate the necessity of drilling holes and uniformly tightening the holding bracket with screws, thereby reducing man-hours and costs. As a result, good contact of the electrodes can be obtained over the entire length of the flexible substrate, and since the structure is such that the alumina substrate is fitted to facilitate movement, there is an effect that thermal warpage due to thermal expansion can be prevented.

[Brief description of the drawings]

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

FIG. 2 is a side view showing another embodiment of the present 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 a detailed structure of a portion A in FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Alumina substrate 5 Flexible substrate 8 Rubber sheet 9 Silicon rubber 20 Substrate base 201 Flat plate part 202 Flexible substrate fixing part

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-58-190138 (JP, A) JP-A-5-8420 (JP, A) JP-A-2-142039 (JP, U) JP-A-1 127750 (JP, U) JP-A-3-116509 (JP, U) JP-A-4-5671 (JP, U) (58) Fields surveyed (Int. Cl. ⁶ , DB name) B41J 2/345

Claims (1)

(57) [Claims] 1. A thermal head array comprising a plurality of heating resistors, a control circuit for selecting an arbitrary heating resistor from the thermal head array based on an external signal, and an external power supply for each heating resistor of the thermal head array. An alumina substrate provided with an electrode for supplying the control circuit and an electrode for connecting the control circuit to an external circuit is fixed to a substrate base, and an electrode provided on the alumina substrate is provided on a flexible substrate. In the structure of the thermal head connected to an external circuit via the electrode, the substrate base is fixed between the flat plate portion fixing the alumina substrate and the surface of the alumina substrate fixed to the flat plate portion between the surface of the alumina substrate. A flexible substrate fixing portion having an end portion having a gap capable of holding the flexible substrate therebetween and having the flexible plate fixedly provided on the flat plate portion. By holding the flexible substrate sandwiched between the tip of the flexible substrate fixing portion and the surface of the alumina substrate fixed to the flat plate portion, the flexible substrate is bent along the surface of the flexible substrate fixing portion and attached, A structure of a thermal head, wherein an electrode of a flexible substrate corresponding to the electrode is pressed against the electrode of the alumina substrate by bending stress of the flexible substrate.