JPH02215546A - Thermal head - Google Patents

Abstract

PURPOSE:To reduce the charging amount of a recording paper and to avoid generation of a breakage or an erroneous operation of a heat generating body and electric components due to the static electricity by making a resinous cover conductive through mixture of carbon fibers into the material thereof, and fixing said resinous cover onto a metallic base by a metallic screw. CONSTITUTION:For example, 8% of carbon fibers is mixed into the resin which is a material of a conventional cover 14. As a result, the insulation resistance of the cover 14 becomes 10<4>-10<6>OMEGA, which is 1/10<9>-1/10<12> the surface electric resistance 10<15>-10<16>OMEGA of the conventional resinous cover. Accordingly, the cover 14 is made highly conductive. The static electricity 19 charging a recording paper 19 is earthed through the conductive cover 14, a screw 17 and a base 11 at a position 20 where the static electricity is in contact with the cover 14.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a thermal head that is a recording component of facsimile machines, printers, and the like.

BACKGROUND OF THE INVENTION In recent years, thermal heads have been widely used in facsimile machines and printers, and the demand for them has been rapidly increasing, and demands for improved performance, lower costs, and higher reliability have been increasing.

An example of the conventional thermal head described above will be described below with reference to the drawings.

FIG. 2 shows the configuration of a conventional thermal head. Referring to Fig. 2, 1 is a base, 2 is a heating element board, 3 is a heating element, 4 is a resin cover, 5 is a platen, 6 is a heating element 30, and a screwdriver used as an example of electrical parts for controlling current flow. xa, 7 is a screw for attaching the cover 4, 8 is a recording paper, and 9 is static electricity on the recording paper 8. Note that the base 1 is sheared to the main equipment.

Conventionally, the cover 4 of this type of thermal head is fixed to the base 1 with screws 7.

Problem to be Solved by the Invention However, in the above configuration, when the recording paper 8 passes over the thermal head, the static electricity 9 on the recording paper 8 is generated by the heating element 3.
And through it, it discharges to the driver I06, causing electrostatic damage and malfunction.

In view of the above-mentioned problems, the present invention has been made to prevent electrostatic damage to the heating element and electrical components for controlling energization thereof, such as the above-mentioned dou-wiper-xae, even if the charged recording paper passes through the thermal head.
The purpose of this invention is to provide a highly reliable thermal head that does not malfunction.

Means for Solving the Problems and In order to achieve the above object, the thermal head of the present invention includes carbon fiber mixed into the material of the resin cover to make it conductive, and the resin cover is attached with metal screws. It is fixed to a metal base.

Function The present invention incorporates carbon fiber into the resin cover of the thermal head, so that when the recording paper is charged, the static electricity is caused to flow through the cover and screws to the base and to the ground, thereby eliminating the charging of the recording paper. It is possible to reduce the amount of electricity and eliminate the occurrence of breakdown and malfunction of heating elements and electrical parts due to static electricity.

EXAMPLE Hereinafter, a thermal head according to an example of the present invention will be described with reference to the drawings. FIG. 1 shows the configuration of a thermal head in an embodiment of the present invention.・First
In the figure, 11 is a base made of aluminum, 12 is an insulating heating element substrate, 13 is a heating element, 14 is a cover, 15 is a platen, and 16 is a driver used as an electric component for controlling the energization of the heating element 13. It is xC. 17 uses the cover 14 as the base 11
A protrusion is formed on the lower surface that contacts the cover 14 with a metal screw for attachment to the cover 14. 18 is recording paper, 19
is the static electricity on the recording paper 18, 20 is the cover 14 and the recording paper 1
This is the curved part where 8 is in contact with the cover 14.
Carbon fibers are exposed on the surface.

In this embodiment, the material of the cover 14 is a conventional resin mixed with 8% carbon fiber.

As a result, the insulation resistance of the cover 14 is 104 to 106 (1; 4), and the surface electrical resistance of the conventional resin is 1015 to 1016 (1/1 compared to Q), as shown in Table 1 below.
It has a high conductivity of about 0' to 1/1012. Therefore, in FIG.
, a conductive cover 14, a screw 17, a base 1
It will be flowed to earth through 1. Therefore, electrostatic damage and malfunction due to static electricity *19 of the heating element 13 and the driver 4016 do not occur, and the reliability of the thermal head can be improved. Specifically, in this example, as shown in Figure 1 below, compared to the electrostatic voltage of 10 to 20 (KV) during recording with a conventional thermal head, the electrostatic voltage was 1 to a (IcV).
), the static electricity 19 on the recording paper is reduced.

In this example, the carbon fiber contained in the material of the cover 14 was set at 8%, but the ratio may be changed.Increasing the carbon fiber content increases the conductivity, and further reduces the static electricity 19 on the recording paper. The effect of reducing

(Margins below) Table 1 Effects of the Invention As described above, the present invention provides a cover made of resin mixed with carbon fiber, and fixes this to a metal base via metal screws. Accordingly, it is possible to provide a highly reliable thermal head that does not cause electrostatic damage or malfunction of the heating element and its electrical components for controlling energization.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a thermal head according to an embodiment of the present invention, and FIG. 2 is a sectional view of a conventional thermal head. 11...Base, 12...Heating element board,
13... From JIJ, 14... Cover, 16... Platen, 16... Driver x C11T... Screw.

Claims (1)

[Claims] A metal base, a heating element insulated and provided on the base, and an electric component that controls energization of the heating element.
The thermal head includes a cover that covers the electrical components and a metal cover that is fixed to the base, and the cover is made of resin containing carbon fiber.