JPH046284Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention is used in equipment such as telephones, where it is necessary to prevent static electricity charged on the human body from discharging to semiconductor components installed in the equipment and protect the internal circuitry. In this field, it is particularly effective for making equipment smaller and thinner.

[Conventional technology]

For example, to explain the knob when using a rotary volume control volume for a telephone, conventionally, as shown in FIGS. , and the front panel 2 of the telephone.
A cylindrical knob 1 with a collar 1a to prevent it from popping out was used. (Utility Model Application No. 55-5461) [Problem to be solved by the invention] However, in this case, the terminal 4a of the volume 4 mounted on the printed circuit board 3 from the front panel of the telephone
If the creepage distance to Ta.

Two main methods have conventionally been used to solve this problem. The first method is to mount the printed circuit board 3 on which the volume 4 is mounted away from the surface of the panel 2, as shown in FIG. It becomes difficult to change. On the other hand, as a second method, as shown in FIG. 5, there is a method of increasing the flange 1a provided on the knob 1 to increase the creepage distance from the surface of the panel 2 to the terminal 4a of the volume 4. , it is necessary to increase the distance between adjacent knobs, making it impossible to arrange the knobs with high density, and as a result, it becomes difficult to miniaturize the telephone.

The present invention is intended to solve the problems of the above-mentioned conventional technology, and implements a volume in a telephone etc.
When the volume is rotated through the cylindrical knob, electrostatic discharge from the human body to the terminals of the volume is prevented, and at the same time, it is possible to make devices such as telephones smaller and thinner.

[Means for solving problems]

The problem is that a ring-shaped groove is formed in the collar provided around the entire circumference of the cylindrical knob, and a ring-shaped groove is formed on the panel side around the hole that engages with the knob, and that engages opposite to the groove. This problem can be solved by providing a protrusion and increasing the creepage distance from the panel surface to the volume terminal.

[Effect]

Generally, telephones are required to have a static electricity resistance of 12KV or more, and the distance between a charged object and a conductor to prevent static electricity discharge is approximately 1 for every 1KV.
mm, so the distance from the surface of the phone to the terminal of the volume must be at least 12 mm, so either the dimension to the printed circuit board on which the volume is mounted needs to be even larger, or the brim of the knob must be made sufficiently large. However, according to the present invention, by appropriately setting the depth of the groove provided in the knob and the height of the ring-shaped protrusion around the hole in the panel, the creepage distance from the panel surface to the volume terminal can be adjusted. This prevents static electricity from being discharged.

〔Example〕

An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a partial sectional view showing the structure of a volume knob and a front panel of a telephone according to the present invention. In FIG. 1, 1 is a knob for rotating the volume, 2 is a panel on the surface of the telephone, 3 is a printed circuit board on which the volume is mounted by soldering, and 4 is the volume. The knob 1 is provided with a collar portion 1a to prevent it from coming off the volume 4 or jumping out from the panel 2, and the collar portion 1a is further provided with a ring-shaped groove portion 1b.
is formed. Here, the collar portion 1a and the groove portion 1b
must be provided seamlessly on the outer periphery of the knob 1. In addition, a fitting part 1c with the volume 4 is formed in the center of the knob 1.
The volume 4 mounted on the printed circuit board 3 by soldering can be rotated through the cap. On the other hand, a ring-shaped protrusion 2a is formed on the panel 2 around the hole in which the knob 1 engages, and is configured to engage with the groove 1b of the knob 1. With such a structure, static electricity has a long creeping distance from the surface of the telephone, passing between the knob 1 and the panel 2, to the volume 4a, making it difficult for static electricity to be discharged.

2 and 3 are diagrams showing the case where the present invention is applied to a switch section and a light emitting diode section, respectively.

〔effect〕

As described above, according to the present invention, even when trying to make the volume knob, switch button, etc. of a telephone, etc. close to each other in order to make it smaller, and at the same time to make it thinner, the static electricity charged on the human body can be Destruction of the internal circuit due to discharge to the conductor can be prevented.

[Brief explanation of the drawing]

Fig. 1 is a partial sectional view of the volume section of a telephone according to the present invention, Fig. 2 is a partial sectional view of the case where the present invention is applied to a switch section, and Fig. 3 is a partial sectional view of the case where the present invention is applied to a light emitting diode section. Figure 4 is a partial cross-sectional view of a conventional technique in which the printed circuit board is moved away from the front panel to prevent static electricity, and Figure 5 is a partial cross-sectional view of a case in which the countermeasure is taken by increasing the knob brim FIG. 3 is a diagram showing a partial cross section. Explanation of symbols, 1...knob, 2...panel, 3
...Printed circuit board, 4...Volume, 5...Push switch, 6...Button, 7...Light emitting diode, 8...Lamp cap.

Claims (1)

[Scope of utility model registration request] In a knob used for a volume part, a switch part, etc. of an operation panel whose housing is made of a plastic molded product, a ring-shaped collar is provided around the entire circumference of the knob, and a ring-shaped groove is formed around the entire perimeter of the knob, The panel side is equipped with a ring-shaped protrusion that engages with the groove of the knob around the entire circumference of the hole where the knob engages, increasing the creepage distance from the panel surface to the conductor part of the volume, switch, etc. Features a rotating knob.