JP2001043768A - Waterproof structure of keybutton - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform waterproofing, dustproofing, and corrosion-proofing using a simple structure by providing a flexible plate, having a plurality of frames to be brought into contact with the back surface side of a panel and the upper surface side of a substrate on both surfaces and for respectively housing key buttons and switches in respective frames on the different surfaces between a key panel and the substrate. SOLUTION: During nonoperation, a projecting part of a key button 12 is pressed up by elasticity of a sheet 11, airtightness between a key panel 13 and the key button 12 is held, and therefore, infiltration of water droplets and dust can be prevented. When the keybutton 12 is depressed, there is a possibility of invasion of liquid such as water or dust 16. However, even if liquid or dust infiltrates a part under the keybutton 12, since a switch 15 is covered with the sheet 11, liquid or dust will not reach the switch 15. Since infiltrated water droplets and dust 17 is partitioned by the frame of the upper part of the sheet 11, it is will not diffuse to the whole surface or the like of the key button 12 part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to waterproofing of a key button, and more particularly to a waterproof structure of a key button for preventing liquid such as water or dust from entering an electric circuit panel.

[0002]

2. Description of the Related Art FIG. 4 is a partial sectional view of a waterproof structure of a key button in a conventional portable communication device. The structure of the conventional key button portion is as follows: an electric circuit panel 26 having switches 24 and 25; and resin and rubber key buttons 21 and 22.
And a key panel 23 that covers them.

FIG. 5 is a partial cross-sectional view of the mounting structure shown in FIG. 4 when a key button is operated. By pressing the key button 21 disposed in the opening of the key panel 23,
The lower protrusion is the switch 24 on the electric circuit panel 26.
Open and close. In this mounting structure, when the key button 21 is pressed, a liquid such as water or dust 27 intrudes from the gap between the key button 21 and the key panel 23, and in addition to the switch 24 which is opened and closed by the key button, the surrounding switch 25 also There is a problem in that it has adverse effects.

FIG. 6 is a partial cross-sectional view of another waterproof structure of a key button in a conventional portable communication device. Two flexible substrates 35 formed on a printed circuit board 34 and having contacts arranged via spacers, and a click plate 37
, A key button 31 having a step portion 33 and a projection 40, and a frame 32, and has a structure in which a waterproof sheet 39 is stretched between the switch portion and the key button. The mounting structure of this key button is such that when the key button 31 is pressed against the upward pressing of the click plate 37 against the key button 31, the contact 40 is formed by the projection 40.
It has a mechanism to open and close.

[0005] In this conventional example, the waterproof sheet 39 shields the switch section and the inside of the key button, thereby increasing the secrecy of the switch.

[0006]

The conventional key button mounting structure has a structure in which the switch is directly opened and closed by the key button. When the key button 21 is pressed as shown in FIG. There is a problem that liquid such as water or dust 27 intrudes into the electric circuit panel 24 from the gap between the button 21 and the circuit short circuit of the electric panel 24, metal parts such as lands and terminals are corroded, and the portable communication device is damaged. Was.
On the other hand, in the case of a structure provided with a waterproof sheet for shielding the switch unit for each key button, the switch unit is not affected even if liquid or dust 27 enters through the gap between the key panel 23 and the key button 21. In this mounting structure, the structure of the switch section is complicated, and it is necessary to form an arrangement space for each key button in the frame itself. Further, a waterproof sheet is arranged between the frame and the switch section. However, there is a disadvantage that the number of manufacturing steps increases and the cost increases.

(Object of the Invention) It is an object of the present invention to provide a mounting structure of a key button of a portable device capable of waterproofing, dustproofing and preventing corrosion with a simple structure.

Another object of the present invention is to provide a waterproof structure of a key button which can prevent liquid such as water or dust from entering an internal electric circuit by using a simple flexible sheet. It is in.

[0009]

According to the present invention, there is provided a waterproof structure for a key button, wherein the key button is provided in an opening of the key panel, and the key button is provided inside the key panel in parallel with the key panel.
A substrate provided with a plurality of switches located below the key buttons; and a plurality of frames (partition frames) provided between the key panel and the substrate and in contact with the back side of the key panel and the top side of the substrate. It is characterized by comprising a flexible sheet that is provided on both sides and accommodates the key buttons and the switches in respective frames on different sides. Further, the switch is constituted by a membrane switch having a click plate on an upper part. Further, the flexible sheet has a protrusion on an upper portion of the switch on an upper surface side of the substrate.

[0010] In the waterproof structure of the key buttons, the plurality of frames of the flexible sheet are provided in a rectangular shape, each accommodating a plurality of key buttons and switches, or provided in a grid shape, each of which is provided with a single frame. And a key button and a switch.

Further, the flexible sheet of the present invention is a sheet formed by molding a silicon material, rubber or the like, and the key buttons are resin or rubber key buttons.

(Function) By arranging a flexible sheet having a partition frame on the front and back sides between a key panel having key buttons and a substrate having switches, penetration of liquid such as water or dust from the key button portion is prevented. It shuts off and prevents diffusion to all key buttons.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a waterproof structure for a key button according to the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing a portable communication device to which a waterproof structure of a key button according to the present invention is applied. An operation panel 2 and a key button 3 are provided on the upper surface of a case 1 of the portable communication device, and an electric circuit panel having a switch engaged with the key button is provided therein.

FIG. 2 is a view showing a cross section taken along the line AA of the portable communication device shown in FIG. The sectional structure of the present embodiment is
An electric circuit panel 14 disposed inside the case 1, a key panel 13 on the upper surface of the case 1, a key button 12 made of resin or rubber, a switch 15 on the electric circuit panel 14, a flexible material formed of silicone material, rubber, or the like. And a sheet (sheet) 11.

The key panel 13 on the upper surface of the case has openings corresponding to the plurality of key buttons 12. Key button 1
2 is a pressing portion which is raised in the center of the cross section and is inserted into the opening of the key panel, an enlarged portion which extends in a flange shape around the pressing portion and abuts on a lower portion of the periphery of the opening of the key panel, and a switch 15 at the lower center. Has a shape consisting of a projection formed at a position corresponding to

Sheet 11 molded of silicon material, rubber, etc.
Has a lower and upper frame respectively to accommodate the switch 15 on the electric circuit panel 14 and the key button of the key panel 13 and to partition the opening, and the lower and upper frames are the electric circuit panel 14 and the electric circuit panel 14 respectively. The sheet portion is formed at a height to be pressed against the key panel 13 and the electric circuit panel
And a key panel 13. Further, the seat 11 may be provided with a projection at a lower portion so as to reliably press the switch 15 when the key button 12 is pressed. Further, an elastic member such as a click plate may be provided at a portion of the switch 15 of the electric circuit panel 14 so as to lift the position of the seat 11 upward.

In the above construction, the projection of the key button 12 is pushed upward by the elasticity of the seat 11 and / or the elasticity of the elastic member when not operated, and the arrangement of each part is maintained as shown in FIG. ing.

FIG. 3 is a diagram showing a cross section taken along the line AA 'of the portable communication device when the key button 12 is pressed. When the key button 12 is pressed, the projection below the key button pushes down the sheet 11 and the switch 15 is pressed.

The waterproof structure of the switch according to the present embodiment has the key panel 13 and the key button 1 in the state shown in FIG.
Since the airtightness is maintained between the second and the second, it is possible to prevent intrusion of water droplets, dust and the like. As shown in FIG. 3, when the key button 12 is pressed, water droplets, dust, and the like 16 may enter. However, even if water droplets enter the lower part of the key button 12, the switch 15 is covered by the sheet 11. By doing so, the switch 15 is not reached. Further, the water droplets, dust 17 and the like that have entered are partitioned by the upper frame of the sheet 11, so that it can be prevented from diffusing to the entire surface of the key button 12 and the like.

Next, as another embodiment of the present invention, the shape of the sheet 1 formed by molding rubber such as a silicon material can be changed. The shape of the partition frame on the upper surface and the lower surface is a square shape for each key button and switch, and has a structure for accommodating a single key button and switch, and a plurality of key buttons and switches for two or more keys. It is possible to adopt a structure which is rectangular and accommodates a plurality of key buttons and switches in one frame. Further, by using a harder material for the front and back partition frame portions than the other portions as the material of the sheet, it is possible to suppress the influence of the deformation of the sheet when operating the key buttons.

[0022]

According to the present invention, since the flexible sheet having the partition frames on the front and back is arranged between the key panel having the key buttons and the board having the switches, the key panel is not operated when the key buttons are operated. Even if liquid such as water or dust enters from the gap of, it accumulates on the sheet and is blocked,
It is possible to prevent short circuit of the electric circuit panel and corrosion of metal parts such as lands and terminals, and it is possible to reduce water-wetting failure and the like. In addition, the partition frame of the flexible sheet can prevent liquid such as water or dust entering the sheet from diffusing to the lower part of all the key buttons.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a portable device to which a waterproof structure of a key button of the present invention is applied.

FIG. 2 is a view showing an embodiment of a waterproof structure for a key button of the present invention.

FIG. 3 is a diagram showing a partial cross section when operating a key button according to the embodiment.

FIG. 4 is a view showing a partial cross section of a waterproof structure of a conventional key button.

FIG. 5 is a diagram showing a partial cross section when a conventional key button is operated.

FIG. 6 is a diagram showing another example of a waterproof structure of a conventional keyboard.

[Explanation of symbols]

 1 case 2, 13, 21, 23, 32 key panel 3, 12, 23, 31 key button 11 sheet 14, 26 substrate 15, 24, 25 switch 16, 27 liquid such as water or dust 17, 28 Dust, etc. 33 Step 32 Printed circuit board 35 Flexible board 36 Contact point 37 Click plate 38 Spacer 39 Waterproof sheet 40 Projection

Claims (5)

[Claims] A key panel provided in an opening of the key panel; a substrate provided inside the key panel in parallel with the key panel and provided with a plurality of switches located below the key button; A plurality of frames provided between the substrate and the back surface side of the key panel and the upper surface side of the substrate are provided on both sides, and the key buttons and the switches are respectively accommodated in the frames on different surfaces. A waterproof structure for key buttons, comprising a flexible sheet. 2. The waterproof structure for a key button according to claim 1, wherein said switch is constituted by a membrane switch having a click plate on an upper part thereof. 3. The waterproof structure for a key button according to claim 1, wherein the flexible sheet has a protrusion on an upper portion of the switch on an upper surface side of the substrate. 4. The waterproof structure for a key button according to claim 1, wherein a plurality of frames of the flexible sheet are provided in a rectangular shape, and each of the frames accommodates a plurality of key buttons and switches. 5. The waterproof structure for a key button according to claim 1, wherein the plurality of frames of the flexible sheet are provided in a grid shape and each store a single key button and a switch.