JPH08115630A - Waterproof type key top board - Google Patents

Abstract

PURPOSE: To provide a waterproof type key top board of such structure that even key tops formed in a position near the periphery of the key top board having the whole of its periphery fixed to another member in order to be waterproofed can be pressed without difficulty. CONSTITUTION: Plural key tops 15 of such structure as to be given by bending the specified parts of a synthetic resin film 13 in its upward direction and forming mould resin 17 in each of recessed parts formed on the reverse-face side of the film 13 through the bending are formed in the film 13, and a fixing face 21 for waterproofness formed all over the periphery of the film 13 is stuck fast to another member in a watertight condition and accordingly fixed to there. A bent section 23 bent in the shape of about a circular arc in the upward direction of the fixing face 21 for waterproofness is formed in a part surrounding the whole of the inside of the fixing face 21 for waterproofness in the film 13 of a waterproof type key top board 11 of such structure like this.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waterproof key top plate.

[0002]

2. Description of the Related Art Conventionally, with downsizing of electronic equipment, there has been a demand for downsizing of push button switches used in its operating portion.

On the other hand, some electronic devices are used in an environment in which moisture or water may enter, and therefore the push-button switch used in the operating portion thereof is also protected from external moisture or water. There is a need for a structure that does not enter the contact part of the switch, a so-called waterproof structure.

In order to meet these demands, there is a push button switch having a structure as shown in FIG. This push button switch is configured by mounting a waterproof key top plate 85 on a switch substrate 71 via a spacer frame 81, and mounting an upper case 95 thereon.

Click plates 75 are mounted on the switch contacts 73 provided on the switch substrate 71.

Further, the waterproof key top plate 85 is constructed by providing a plurality of key tops 89 in a single synthetic resin film 87 having no through holes. Each key top 8
9 is formed by bending a predetermined portion of the synthetic resin film 87 in an upward direction and at the same time molding a mold resin 91 in a concave portion formed on the back surface side by the bending. A pressing portion 93 for pressing the click plate 75 is provided on the lower surface of the mold resin 91.

Further, each key top 89 is provided on the upper case 95.
There is a hole 97 for exposing the surface of the.

The entire periphery of the waterproof key top plate 85 is watertightly sandwiched between the spacer frame 81 and the upper case 95, or the entire periphery of the waterproof key top plate 85 is the spacer frame 81 or the upper case. If it is watertightly adhered to 95, even if a water drop on the upper case 95 enters on the waterproof key top plate 85, the water drop will still be present on the switch substrate 71.
It doesn't invade on and is waterproof. The sandwiching portion or the adhesive portion around the waterproof key top plate 85 is hereinafter referred to as a waterproof fixing surface 100.

[0009]

By the way, the above-mentioned conventional push button switch plate is miniaturized, so that the waterproof key top plate 85 is used.
The space L1 between the key tops 89 is narrow, and the space L2 between the surrounding key tops 89 (on the left and right ends in FIG. 2) and the waterproof fixing surface 100 is also narrow.

When the internal key top 89 (two central ones in FIG. 2) is pressed, the key top 89 is pressed.
Since the distance from the to the waterproof fixing surface 100 that is fixed is relatively long, the waterproof key top plate 85 bends relatively easily by the pressing stroke of the key top 89, which makes pressing difficult. Does not occur in particular.

However, when the surrounding key tops 89 are pressed, the distance from the key tops 89 to the fixed waterproof surface 100 is only L2, which is short. Therefore, the waterproof key tops corresponding to the pressing stroke of the key tops 89 are short. It is difficult for the portion of the plate 85 on the waterproof fixing surface 100 side to bend,
There is a problem that the pressing becomes difficult.

The present invention has been made in view of the above points, and an object of the present invention is to provide a key top provided near the periphery of a key top plate whose outer periphery is fixed for waterproofing. It is to provide a waterproof key top plate that can be easily pressed.

[0013]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention allows a predetermined portion of a synthetic resin film to be bent upward in a single synthetic resin film and is formed on the back surface side by the bending. A waterproof key top having a structure in which a plurality of key tops each having a molded resin formed therein are provided in the recessed portion and the waterproof fixing surface of the entire periphery of the synthetic resin film is water-tightly adhered to another member to be fixed. In the plate, a portion that surrounds the entire inside of the waterproof fixing surface of the synthetic resin film is provided with a curved portion that curves upward or downward from the surface of the waterproof fixing surface in a substantially arc shape.

[0014]

The waterproof fixed surface around the waterproof key top plate is fixed in close contact with another member such as a spacer or a case. At this time, the distance between the surrounding keytops and the waterproof fixing surface to be fixed is short, but since there is a curved portion between them, the distance between the surrounding keytops and the waterproof fixing surface is substantially that much. It's getting longer. Therefore, when the surrounding key tops are pressed by the lengthened length, the synthetic resin film on the curved side easily bends, and therefore the key tops can be pressed easily.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic side sectional view showing a push button switch formed by using a waterproof key top plate 11 according to one embodiment of the present invention. As shown in the figure, this push button switch is configured by mounting a waterproof key top plate 11 on a switch substrate 41 via a spacer frame 51, and attaching an upper case 61 thereon.

The switch board 41 is a membrane switch, and click plates 45 are mounted on the switch contacts 43 provided on the switch board 41.

The upper case 61 is provided with holes 63 for exposing the key tops 15 described below on the surface thereof.

The spacer frame 51 is inserted to provide a predetermined space between the switch substrate 41 and the waterproof key top plate 11.

The waterproof key top plate 11 is constructed by providing a plurality of key tops 15 in a single synthetic resin film 13 having no through holes. Each key top 15 is configured by bending a predetermined portion of the synthetic resin film 13 in an upward direction and at the same time molding a molding resin 17 in a recess formed on the back surface side by the bending. A pressing portion 19 for pressing the click plate 45 is provided on the lower surface of the mold resin 17.

Further, the waterproof key top plate 11 includes
A flat waterproof surface 21 is provided so as to surround the entire synthetic resin film 13. This waterproof fixed surface 21
Is watertightly sandwiched and fixed between the upper case 61 and the spacer frame 51.

As a result, even if a water drop on the upper case 61 enters the waterproof key top plate 11, the water drop does not enter under the waterproof key top plate 11 and is waterproofed.

In the present embodiment, the waterproof fixing surface 21 is formed in the portion surrounding the entire inside of the waterproof fixing surface 21 of the synthetic resin film 13 constituting the waterproof key top plate 11.
A curved portion 23 is provided so as to be curved upward in a substantially ¼ arc shape from the surface.

Each key top 1 of this push button switch
When 5 is pressed, the waterproof key top plate 11 bends and descends, and the pressing portion 19 inverts the click plate 45 and turns on the switch contact 43 therebelow.

Here, also in this waterproof type key top plate 11, the space L2 between the surrounding key tops 15 (on the left and right ends in FIG. 1) and the waterproof fixing surface 21 is narrowed for downsizing. In the case of the present embodiment, since the curved portion 23 is provided, the length between the surrounding key top 15 and the waterproof fixed surface 21 is substantially longer than that by L2. For this reason, when the surrounding key tops 15 are pressed, the key tops 15 can be easily bent due to the increased deformable length, so that the key tops 15 can be easily pressed.

Since the internal key tops 15 (the two central ones in FIG. 1) are both distant from the waterproof fixed surface 21, the waterproof key top plate 11 is easily bent and pressed as before. You can do it.

Next, FIG. 3 is a diagram showing an example of an actual concrete structure of the waterproof key top plate 11, and FIG. 3 (a) is a plan view.
The same figure (b) is the AA sectional view of the same figure (a), and the same figure (c) is the BB sectional view of the same figure (a). FIG. 4 is FIG.
It is an enlarged view of C part of (c). The same parts as those of the waterproof key top plate 11 shown in FIG. 1 are designated by the same reference numerals.

As shown in FIG. 3, a waterproof fixing surface 21 is provided all around the waterproof key top plate 11, and this portion is provided with the upper case 61 and the spacer frame 51 shown in FIG. Is water-tightly sandwiched or is water-tightly adhered to the spacer frame 51 or the upper case 61 for waterproofing.

A curved portion 23 (see FIG. 4) is provided in a portion surrounding the entire inner side of the waterproof fixing surface 21 so that the surface of the waterproof fixing surface 21 is curved upward in a substantially arc shape. ing.

Further, notches 111, 111 for positioning are provided on both sides of the waterproof key top plate 11, and the waterproof fixing surface 21 and the curved portion 23 are provided with the notches 1.
It is provided so as to avoid 11 and 111 and surround the inner periphery thereof.

Next, in order to manufacture this waterproof type key top plate 11, as shown in FIG. 5, an upper mold 201 having a recess 203 having the same shape as the upper part of the key top 15,
A lower mold 301 having a recess 303 having the same shape as the lower part of the key top 15 is prepared. Also the upper mold 201
The curved concave surface 205 having the same shape as the upper surface of the curved portion 23.
The lower die 301 is also provided with a curved convex surface 305 having the same shape as the lower surface of the curved portion 23.

Then, the flat synthetic resin film 13 is sandwiched between the upper and lower molds 201 and 301, and the recess 3 of the lower mold 301 is held.
When the high-temperature molten resin is press-fitted from the pin gate 307 attached to the No. 03, the synthetic resin film 13 thereon is pushed up and deformed in the direction of the arrow shown in FIG. At the same time as closely contacting the inner surface, the molten resin is filled in the recesses 203 and 303.

At the same time, the curved concave and convex surfaces 205, 3 are simultaneously formed.
In No. 05, the synthetic resin film 13 is formed into a substantially 1/4 circular arc shape by the heat and the clamping pressure of the upper and lower molds 201 and 301.

Then, by removing the upper and lower molds 201 and 301, the waterproof key top plate 11 having the key top 15 and the curved portion 23 provided on the synthetic resin film 13 is formed.

In this manufacturing method, the key top 15 and the curved portion 23 are simultaneously formed by one set of upper and lower molds, but they may be manufactured by different upper and lower molds in different steps. Further, the curved portion for each key top 15 and the curved portion 23 on the outer periphery are formed in advance by preforming only the synthetic resin film 13, and the molded portion is formed in the curved portion for each key top 15 in the next step. The resin 17 may be molded and manufactured.

Although the curved portion 23 of the above embodiment is constructed by bending the surface of the waterproof fixed surface 21 upward in a substantially arcuate shape, it is conversely curved downward in a substantially arcuate shape. Alternatively, it may be curved in a semi-circular shape, or may be curved in a wave shape in the vertical direction.

By the way, in the waterproof key top plate 11 shown in FIG. 3, the key tops 15 located at the four corners have the worst movement. Therefore, as shown in FIG. 6, in addition to the bending portion 23, a second bending portion 33 may be provided around the key top 15 located at the corner.
That is, the curved portion may be provided in two stages. According to this structure, even the key tops 15 located at the corners can move smoothly.

Further, as shown in FIG. 7, only the curved portion around the key top 15 located at the corner may be a wavy curved portion 23 'which is curved in a wavy shape for better movement.

[0038]

As described in detail above, according to the waterproof key top plate of the present invention, the waterproof key top plate is fixed to the fixed portion of the waterproof key top plate whose outer periphery is fixed in a watertight manner for waterproofing. Even a key top provided at a close position has an excellent effect that it can be easily pressed.

[Brief description of drawings]

FIG. 1 is a schematic side sectional view showing a push button switch configured by using a waterproof key top plate 11 according to an embodiment of the present invention.

FIG. 2 is a schematic side sectional view showing a conventional waterproof push button switch.

FIG. 3 is a diagram showing an example of an actual specific structure of the waterproof key top plate 11 according to the present invention, FIG. 3 (a) is a plan view,
The same figure (b) is the AA sectional view of the same figure (a), and the same figure (c) is the BB sectional view of the same figure (a).

FIG. 4 is an enlarged view of portion C in FIG. 3 (c).

FIG. 5 is a diagram showing a method of manufacturing the waterproof key top plate 11.

6A and 6B are views showing another embodiment, in which FIG. 6A is a perspective view of a main part and FIG. 6B is a side sectional view of the main part.

FIG. 7 is a side sectional view of an essential part showing another embodiment.

[Explanation of symbols]

 11 Waterproof Key Top Plate 13 Synthetic Resin Film 15 Key Top 17 Mold Resin 21 Waterproof Fixed Surface 23 Curved Part

Claims (1)

[Claims] 1. A key top having a structure in which a predetermined portion of a synthetic resin film is curved upward in one synthetic resin film and a mold resin is molded in a concave portion formed on the back surface side by the curvature. In a waterproof key top plate having a structure in which a plurality of waterproof fixing surfaces around the entire synthetic resin film are tightly adhered to other members in a watertight manner, the entire inside of the waterproof fixing surface of the synthetic resin film is A waterproof key top plate, characterized in that a curved portion that is curved upward or downward from the surface of the waterproof fixed surface in a substantially arc shape is provided in the surrounding portion.