JPH0234839Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Field of industrial application This invention relates to a device that prevents electrostatic damage to circuit components due to discharge of electrostatic charges accumulated on the human body when operating the knobs of electronic equipment.

(B) Prior art In general, the human body is often charged with electricity due to friction, etc., which can reach up to several Kv, and electronic devices, especially operating knobs made of resin with metal plating, protrude from resin panels. When operating an electronic device with your fingers, where the conductor on the surface of the operation knob is electrically floating from other conductors, the electrostatic charge on your body passes through the conductor on the operation knob to the conductor on the circuit board. For example, so-called electrostatic damage may occur, in which semiconductor components are destroyed by the impact of discharge to the ground line or +B line.

Therefore, we developed a technology to prevent electrostatic damage.
This is disclosed in Publication No. 57-146379 and the like. However, the device disclosed in this publication places a conductive member close to the operating knob and grounds the conductive member, requiring a separate member for grounding and complicating the wiring. Further, although the purpose is not to prevent electrostatic damage, there is a method such as Japanese Utility Model Publication No. 56-42470 that simplifies the ground wiring.
In the device disclosed in this publication, a ground terminal plate is fixed to a stand, and the bottom plate is brought into contact with the ground terminal plate at the same time as it is attached to the stand. However, it was not possible to wire the wires to the ground terminal board smoothly.

(c) Purpose of the invention The purpose of this invention is to provide an electrostatic damage prevention device that smoothly grounds static electricity accumulated in the human body and simplifies the earth wiring.

(d) Structure of the invention The present invention includes a conductive switch nameplate formed in the vicinity of an operation button for operating a switch on a printed circuit board mounted in a synthetic resin frame, and a conductive switch nameplate formed on the periphery of the switch nameplate inside the frame. A locking tongue that is inserted and locked, a grounding body that extends from the locking tongue toward the frame opening, and a conductive cover plate that closes the frame opening and contacts the grounding body. By forming this structure, static electricity can be grounded reliably and ground wiring to the lid plate can be easily performed.

(e) Examples The electrostatic damage prevention device can be used in various electrical devices using electronic circuits, such as video tape recorders, cassette tape recorders, televisions, rice cookers, electric fans, and the like. Therefore,
The present invention is based on the first embodiment using an electric fan as an example shown in FIGS. 1 to 5, the second embodiment shown in FIG. 6 also using an electric fan as an example, and the third embodiment shown in FIG. Explain.

A first example will be described.

The electric fan 1 has a synthetic resin base 3 with a support 2 protruding from it.
and a fan main body 4 supported by the pillar 2. Inside the base 3, a printed circuit board 5 is fixed to a boss 7 with screws 6, which incorporates an electronic circuit for stopping and regulating the speed of the blower motor, oscillation motor, etc. of the fan main body 4. The base 3 has an insertion hole 9 through which a display light emitter 8 mounted on the printed circuit board 5 projects, and an insertion hole 12 through which an operation button 11 for operating a control switch 10 mounted on the printed circuit board 5 projects. is forming. Said operation button 1
1 is supported by an elastic piece 13 attached to the inner surface of the base 3. A switch name plate 14 made of a conductive material is attached to the upper surface of the base 3 from which the light emitting body 8 and the operation button 11 protrude. The switch nameplate 14 has an insertion hole 15 through which the light emitting body 8 and the operation button 11 protrude.
16 is formed. Locking tongues 17 are formed at several locations around the periphery of the switch nameplate 14. The locking tongue piece 17 is inserted into the base 3 through a small hole 18 formed in the base 3, and the switch nameplate 14 is attached to the base 3 by bending its tip. A boss 19 vertically installed in the base 3 has a screw 2.
At 0, the plate-shaped grounding body 21 is attached. Continuing from the side surface of the boss 19, a rib 22 is formed within the base 3. One end of the grounding body 21 is connected to the locking tongue piece 1 by utilizing the elasticity of the grounding body 21 itself.
7. The other end of the ground body 21 extends along the edge of the rib 22 and projects toward the opening of the base 3. The opening of the base 3 is closed with a cover plate 23 made of a conductive material. The lid plate 2
3 is fixed by a screw 25 screwed into a boss 24 protruding from the base 3. The other end of the ground body 21 contacts the lid body 23 . Therefore, the switch nameplate 14 is grounded to the cover plate 23 via the ground body 21.

The second embodiment shown in FIG.
Since the grounding body 31 is integrally formed with 4, the number of parts is reduced and the efficiency of assembly work is also improved.

In the third embodiment shown in FIG. 7, a boss 32 is provided protrudingly near the protruding and bent portion of the locking tongue piece 17 of the base 3.
A conductive coil spring-like grounding body 33 is fitted into the boss 32, and one end of the grounding body 33 is brought into contact with the locking tongue piece 17. Boss 3 of the ground body 33
2 is supported by making a part of the grounding body 33 small in diameter and sandwiching the sides of the boss 32. Also, the boss 32
is for positioning the cover plate 23, and the ground body 33
The locking tongue 17 will not move due to vibration and come off from the locking tongue 17.

(f) Effects of the invention This invention has the advantage that the switch nameplate and the cover plate can be electrically connected easily without the need for soldering or fixing with screws even with a grounding body.

[Brief explanation of the drawing]

Figures 1 to 5 show a first embodiment of an electric fan adopting the present invention, in which Figure 1 is a sectional view of main parts, Figure 2 is a perspective view, and Figure 3 is a bottom view of the base. figure,
FIG. 4 is a sectional view of the base, FIG. 5 is a perspective view of the main part, and FIG. 6 is a perspective view similar to FIG. 5 showing the second embodiment.
FIG. 7 is a perspective view of essential parts showing the third embodiment. 3... Base (frame body), 5... Printed circuit board, 1
1...Operation button, 14...Switch nameplate, 17...
Locking tongue piece, 21... Earth body, 23... Lid plate.

Claims (1)

[Scope of utility model registration request] A conductive switch nameplate formed close to an operation button for operating a switch on a printed circuit board mounted in a synthetic resin frame, and a locking tongue formed on the periphery of the switch nameplate and inserted and locked into the frame. A piece and
An electrostatic damage prevention device comprising a grounding body extending from the locking tongue toward the frame opening, and a conductive cover plate that closes the frame opening and contacts the grounding body.