JPH10162686A - Key sheet rubber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simply assembled key sheet rubber by providing compressiondeformable ribs at the peripheral edge section of the surface of the key sheet rubber, inserting the ribs into the recesses of a case, and concurrently positioning and fixing them and providing a splash-proof function. SOLUTION: A key sheet rubber 11 is fitted to the back face of a case 14, the ribs 12 of the key sheet rubber 11 are pressed into the recesses 15 on the back face of the case 14, and the case 14 and key sheet rubber 11 are positioned. Contact point terminals 16 are stuck to a substrate 17, the substrate 17 is fixed to a chassis 18 by pawls 19, the chassis 18 is arranged below the key sheet rubber 11, and the pawls 21 of the chassis 18 are hooked on the pawls 20 of the case 14 to fix the chassis 18. When force is applied to a button 13 in the direction of an arrow F, the dome-like contact point terminal 16 is warped into contact with a contact point section on the surface of the substrate 17 for conduction. When the force in the direction of the arrow F is removed from the button 13, the contact of the substrate 17 is removed by the reaction of the dome-like contact point terminal 16 for nonconduction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a key sheet rubber used for a keypad of a portable information terminal device, a portable radio telephone device and the like.

[0002]

2. Description of the Related Art Conventionally, the splash-proof structure of key sheet rubber is as follows.
As shown in FIG. 3, a substrate 5 on which an edge portion 3 which facilitates compression deformation is formed at a peripheral portion of the surface of the key sheet rubber 2 and on which a contact terminal 4 pressed by the key sheet rubber 2 is formed.
Is hooked on the claws 6 of the housing 1 so that the edge 3 of the key sheet rubber 2 is pressed against the back surface of the housing 1 to seal the back surface of the housing 1 and the periphery of the key sheet rubber 2. You.

[0003]

However, in the conventional splash-proof structure of the key sheet rubber, since the edge portion 3 is pressed against the back surface of the housing 1, a reaction force of the rubber acts, and the contact terminal 4 is pressed. Since the substrate 5 configured as described above is hooked on the claws 6 of the housing 1, there is a problem that the assemblability is poor and a positional shift due to the assembling is likely to occur.

An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a key sheet rubber which is easy to assemble, can be easily positioned, and has a splashproof structure.

[0005]

According to the present invention, in order to achieve the above object, a compressible deformable rib is provided on a peripheral portion of a surface of a key sheet rubber, and the rib is fitted into a concave portion of a housing. The positioning and fixing and the splash-proof function are simultaneously realized.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION
A key sheet rubber that has a rib that can be compressed and deformed is provided on the periphery of the surface of the key sheet rubber, and the rib is fitted into a recess formed on the back surface of the housing to enable positioning and fixing to the housing and a splash-proof function. Thus, the positions of the housing and the key sheet rubber are determined by simple assembly, and the peripheral edges of the housing and the key sheet rubber are sealed, so that a splash-proof structure becomes possible.

According to a second aspect of the present invention, the key sheet rubber, including the key buttons, is integrally formed of rubber, so that the key sheet rubber can be manufactured at low cost.

In the invention according to claim 3 of the present invention, the key sheet rubber is formed integrally with the key button made of resin, and the key button design can be changed in various ways.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an external perspective view of a key sheet rubber according to the present embodiment. In FIG. 1, a rib 12 for facilitating compression deformation is formed on a peripheral portion of the surface of the key sheet rubber 11. On the surface of the key sheet rubber 11, conduction is ON, O
A button 13 for performing FF is formed.

FIG. 2 is a cross-sectional view of the key sheet rubber splash-proof structure according to the present embodiment. A concave portion 15 for engaging the rib 12 is formed on the rear surface of the housing 14 with a peripheral length similar to that of the rib 12 of the key sheet rubber 11. The dome-shaped contact terminal 16 is used to establish conduction with the substrate 17.
It is configured between the key sheet rubber 11 and the substrate 17.

The key sheet rubber portion is assembled as follows. First, the key sheet rubber 1
Attach 1. Here, the ribs 12 of the key sheet rubber 11 are pressed into the recesses 15 on the back surface of the housing 14. In this state, the housing 14 and the key sheet rubber 11 are positioned. Also,
The housing 14 and the key sheet rubber 11 are temporarily fixed, and there is no fear that they will come off during assembly. Next, the contact terminals 16 are adhered to the substrate 17, the substrate 17 is fixed to the chassis 18 by the claws 19, and the chassis 18 is arranged below the key sheet rubber 11, and the chassis 18 is The hook 21 is hooked and fixed.

Next, the operation of the key sheet rubber portion will be described. When a force is applied to the button 13 in the direction of arrow F, the dome-shaped contact terminal 16 bends and contacts the contact portion on the surface of the substrate 17 to conduct. When the force indicated by the arrow F is removed from the button 13, there is no contact with the substrate 17 due to the reaction force of the dome-shaped contact terminal 16, and the button 13 does not conduct.

In the above embodiment, the key sheet rubber 1
1 may be formed integrally using silicon rubber or vinyl chloride, or may be a two-material key sheet formed integrally with rubber by forming only the button 13 with resin.
In the latter case, the design of the key button 13 can be variously changed.

[0014]

According to the present invention, as is apparent from the above embodiment, a rib for facilitating compressive deformation is formed on the periphery of the surface of the key sheet rubber with the same peripheral length as the rib on the back surface of the housing. By engaging with the concave portion, the position of the housing and the key sheet rubber is determined, and the key sheet rubber capable of realizing the splash-proof structure by simple assembly can be provided.

[Brief description of the drawings]

FIG. 1 is an external perspective view of a key sheet rubber according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the key sheet rubber in a splash-proof structure.

FIG. 3 is a sectional view of a conventional key sheet rubber having a splash-proof structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Key sheet rubber 12 Rib 13 Button 14 Housing 15 Depression 16 Contact terminal 17 Substrate 18 Chassis 19, 20, 21 Claw

Claims (3)

[Claims] 1. A key which can be compressed and deformed is provided on a peripheral portion of the surface of a key sheet rubber, and the rib is fitted into a concave portion formed on the back surface of the housing, thereby positioning and fixing to the housing and a splash-proof function. Key sheet rubber that made it possible. 2. The key sheet rubber according to claim 1, wherein the whole, including the key buttons, is integrally formed of rubber. 3. The key sheet rubber according to claim 1, wherein the key buttons are made of resin and are integrally formed of rubber.