JPS5850415Y2 - keyboard device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a keyboard device useful for use in a calculator wristwatch or a watch-type calculator.

The applicant is Utility Application No. 52-135 dated October 7, 1978.
No. 495 (Utility Model Publication No. 54-61278 or Publication of Utility Model Publication No. 54-61278)
(Refer to Publication No. 7-45631) Based on the name of the invention, "Small Keyboard Device," a resin film with excellent pinhole strength and tensile strength is used between the push button and the flat seat cushion mat that restores the push button to its original state. We proposed a method that uses a sheet.

This makes it easy to make it thinner and more compact, and the resin film sheet increases the repeated fatigue strength of the flat seat cushion mat, extending its lifespan, without compromising its function as a cushion mat. Beneficial.

The present invention further improves this and provides a keyboard device with long life and excellent water resistance.

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

FIG. 1 is an external view of an electronic wristwatch with a calculator, which is equipped with a display section that switches between displaying computer information or clock information, and a keyboard device K for setting time and inputting information into the calculator.

Note that / and /i are installed in the keyboard device by being press-fitted into a recessed fitting portion (not shown) formed in the watch case C through a backing or the like.

FIG. 2 is a cross-sectional view of the main part of the keyboard device, showing the normal state and FIG. 3 showing the state when one push button is being pressed. For convenience, only two push buttons are shown here. In reality, an appropriate number of pushbuttons are arranged as shown in the external view of FIG.

The push button 2, which partially protrudes through the opening of the key housing 1, can be operated to suppress, and when pressed, the resin film sheet 3 and the flat seat cushion mat 4 are bent downward by its stroke.

The flexible film circuit board 5 is arranged along the lower surface of the flat sheet cushion mat 4, and when it is bent according to the sheet cushion mat 4, it comes into contact with the fixed contacts Ta of the pace circuit board γ, which were isolated via the spacer 6, and is electrically connected. Continuity is established.

In the normal state when the push button 2 is not pressed, the flat seat cushion mat 4 returns to its original state (
The push button 2 and the resin film sheet 3 are also returned to their original states.

Similarly, in this state, the flexible film circuit board 5
The flexible film circuit board 5 and the base circuit board 7 are separated by a certain distance by an insulating spacer 6.

The adhesive sheet 8 is interposed between the key housing 1 and the flat seat cushion mat 4 (D) at the outer peripheral edge thereof, and adheres the two to maintain waterproofness between them.

The resin film sheet 3 is a flat sheet cushion mat 4
In order to increase the cyclic fatigue strength of pushbutton 2,
It is necessary to have excellent pinhole strength and tensile strength.

Furthermore, it is desirable that the thickness be as thin as possible.

From a practical standpoint, the thickness of the resin film sheet 3 is set to 25μ.
In terms of materials, nylon film sheets and Teflon sheets are optimal.

Of course, polyester film sheets, PVC sheets, polyimide sheets, polyethylene sheets,
Vinylidene chloride film sheets, polyester film sheets, vinyl film sheets, etc. can also be used.

By using the above-mentioned resin film sheet 3, the flat seat cushion mat 4 can be made of existing materials that function as a cushion mat, and when the thickness is about 300 to 400 μm, chloroprene rubber, nitrile butadiene rubber, silicone rubber, Rubber-based materials such as natural rubber are suitable.

As the water-resistant adhesive sheet 8, a double-sided adhesive tape or a heat-adhesive sheet is effective.

Assuming the sheet thickness is about 100μ and the sheet width is about 1mm,
In the case of a double-sided adhesive tape made of a nonwoven fabric with a thickness of about 50 μm impregnated with an acrylic adhesive, a pressure resistance of 1 to 2 atmospheres can be obtained.

In the case of a thermocompression bonded film sheet with the same sheet thickness and sheet width, if a nonwoven fabric with a thickness of about 50 μm is impregnated with a chloroprene adhesive, if the flat seat cushion sheet 4 is made of chloroprene rubber, it will be 140 to 1
By heating and pressurizing at 80° C. and 2 to 4 kg/crIL for 20 to 60 seconds, a pressure resistance of 3 to 5 atmospheres can be obtained.

Generally, a pressure resistance of 1 to 5 atmospheres is sufficient, and the above-mentioned one satisfies this.

In addition, as shown in the cross-sectional view of FIG. 4, if the outer periphery of the waterproof adhesive sheet 8 is reinforced with an adhesive 9 having an appropriate viscosity such as epoxy adhesive, the pressure resistance will further increase, and in the case of double-sided adhesive tape. The pressure can be 2 to 3 atmospheres, and 5 to 7 atmospheres in the case of a thermal adhesive sheet.

In addition, in order to increase adhesive strength, the adhesive surface of the key housing 1 and the adhesive surface of the flat seat cushion mat 4 may be roughened by sandblasting or other methods.

This is particularly effective when silicone rubber, which has a slightly low adhesive strength, is used as the flat seat cushion mat 4.

By the way, the resin film sheet 3 is formed smaller than the inner frame size of the water-resistant adhesive sheet 8.

This is to prevent the resin film sheet 3 from being overlapped with the water-resistant adhesive sheet 8 when bonding the key housing 1 and the flat seat cushion mat 4 with the water-resistant adhesive tape 8, and the flat seat cushion mat 4 to improve the reliability of waterproofing.

Moreover, as a result, the outer periphery of the resin film sheet 3 becomes a free end, which can sufficiently and easily cope with the deflection due to the depression of the push button 2, and achieve its full effect.

FIG. 5 is an exploded perspective view showing the relationship between the resin film sheet 3, the adhesive sheet 8, and the flat sheet cushion mat 4. Here, for convenience of handling, the resin film sheet 3 is pasted onto the flat sheet cushion mat 4 with a rubber adhesive. Both are integrated.

Of course, functionally, the resin film sheet 3 may simply be placed on the flat seat cushion mat 4.

In addition, during the pressing operation of the push button 2, the bending of the resin film sheet 3 and the flat seat cushion mat 4 is concentrated at the periphery of the lower surface of the push button 2, and even though the resin film sheet 3 is interposed, the cyclic fatigue strength of this part is becomes the smallest.

In this embodiment, in order to improve this, the pushbutton 2 in FIG.
As is clear from the cross-sectional view, the chamfer α° is formed in accordance with the shape corresponding to the bending of the resin film sheet 3 and the flat seat cushion mat 4.

For example, in this example, the stroke is 100 to 300μ.
It is quite good that α0 is around 10 to 20'.

Flexible film circuit board 5 (/i) Due to the recovery force, for example, a polyimide film base material having a thickness of 50 μm is suitable.

In the above embodiments, a keyboard device for an electronic wristwatch with a calculator has been described, but the present invention can be similarly implemented in wristwatch type calculators and other portable devices.

As described above, according to the present invention, in a keyboard device in which a resin film sheet with excellent pinhole strength and tensile strength is interposed between a push button and a flat seat cushion mat that returns the push button to its original state, the key housing and the flat seat cushion mat are interposed. The seat cushion mat is adhered to the outer peripheral edge using a water-resistant adhesive sheet, and the resin film sheet is formed to be smaller than the inner frame size of the water-resistant adhesive sheet.
The key housing and the flat seat cushion mat can be bonded together without the resin film sheet overlapping the water-resistant adhesive sheet, providing a highly reliable water-resistant effect, and the resin film sheet increasing the cyclic fatigue strength, providing a useful keyboard device. can.

[Brief explanation of the drawing]

Fig. 1 is an external view showing an example of a wristwatch with a calculator, Fig. 2 is a cross-sectional view showing an embodiment of the present invention, Fig. 3 is a cross-sectional view showing a different state from Fig. 2, and Fig. 4 is a cross-sectional view showing the present invention. FIG. 5 is an exploded perspective view showing the main parts of the embodiment of the present invention, and FIG. 6 is a sectional view showing the main parts of the same embodiment. 1...Key housing, 2...Push button, 3...Resin film sheet, 4...
-Flat seat cushion mat, 5...Flexible film circuit board, 6...Insulating spacer, 7...Base circuit board, 8...Waterproof adhesive sheet.

Claims (1)

[Scope of utility model registration request] A resin film sheet with excellent pinhole strength and tensile strength is interposed between the pushbutton and the flat seat cushion mat that returns the pushbutton to its original state, and the key housing and the above seat cushion mat are waterproof bonded at the outer periphery. 1. A keyboard device, characterized in that the resin film sheet is adhered by a sheet, and the resin film sheet is formed to be smaller in size than the inside dimension of the frame of the water-resistant adhesive sheet, and the outer periphery of the resin film sheet is a free end.