JPS5914988Y2 - push button switch device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a push button switch device that opens and closes contacts by operating a push button.

2. Description of the Related Art In order to reduce the size and thickness of small-sized electronic devices, such as small-sized electronic calculators, push-button switch devices are used in which movable contact portions are formed from contact sheets made of rubber.

This type of push button switch device has a structure in which a hollow frustum-shaped bulge is formed in a rubber sheet, and a movable contact is provided inside the head of the bulge, and the head is pressed by a push button. The bulge is elastically deformed downward to bring the movable contact into contact with the fixed contact on the circuit board.

However, this rubber sheet cannot be made very thin due to its material and technical limitations in terms of the thickness that can be processed or the thickness that can be put to practical use.

Therefore, it has been considered to use a contact sheet made of a synthetic resin film that can be made thin materially and technically in place of the rubber sheet.

However, since the synthetic resin film is harder than rubber, when the contact sheet is pressed by operating the push button, the contact sheet does not deform stably and uniformly.

For this reason, the movable contacts provided on the contact sheet are not pressed stably and do not come into stable and uniform contact with the fixed contacts, leading to unstable switch-on operation and the possibility of chattering or double make.

Therefore, there are actually problems in using a synthetic resin film as a contact sheet.

By the way, in conventional push button switch devices, the push button and the contact sheet are constructed as separate bodies, and the push button is fitted into the button hole of the computer case independently of the contact sheet.

For this reason, in the assembly process, each push button is fitted into the button hole of the computer case, and it takes a lot of effort to assemble the push button, and it is also difficult to position the push button and the button hole, and to prevent the push button from coming out of the button hole. The assembly work is very troublesome as it involves handling the case and positioning the push button fitted into the button hole and the movable contact of the contact sheet.

Furthermore, the push button has a flange that prevents it from being pulled out from the button hole of the case, which complicates the mold structure when molding the push button from synthetic resin material, increasing manufacturing costs. .

Therefore, when using a contact sheet made of a synthetic resin film, it is also desired to eliminate such drawbacks.

The present invention was developed in view of the above circumstances, and allows the movable contact to stably contact the fixed contact when the push button is operated, making it thinner by using a synthetic resin film as the contact sheet, and making it easier to assemble the push button. The present invention provides a push button switch device that is streamlined and reduces manufacturing costs.

Embodiments of the present invention shown in the drawings will be described below.

The drawing shows an embodiment in which the push button switch device of the present invention is applied to a small electronic calculator.

In the figure, 1 is an upper case, 2 is a lower case, and inside these cases 1 and 2 combined, a contact sheet 3 and a circuit board 4 are provided in a layered structure.

The upper case 1 has a display window 5 for a liquid crystal display device, etc., and a plurality of regularly arranged rectangular button holes 6.

The contact sheet 3 is made of an insulating synthetic resin film such as polyurethane, polyester, polyimide, etc., and has a rectangular sheet shape that covers the area where the button holes 6 are arranged.

Note that the thickness of the contact sheet 3 is approximately 50 μm.

Each button hole 6 of the upper case 1 is provided on the upper surface of the contact sheet 3.
A plurality of circular convex portions 7 corresponding to...
. . is formed, and a plurality of push buttons 8 . . . forming a rectangular parallelepiped correspond to each button hole 6 .
It is glued through...

The convex portions 7 are formed by applying an elastic insulating material such as silicone rubber by screen printing, and have a thickness of about 200 μm.

The push button 8 is made of insulating synthetic resin, for example, is formed by a punching method, and is a rectangular parallelepiped that can be fit into the button hole 6 of the upper case 1 so as to be able to move up and down. is doing.

Note that the push buttons 8 are thicker than the upper case 1, and do not have a flange for preventing them from coming off.

Then, the push buttons 8 are placed on the convex portions 7 and the upper surface of the contact sheet 3 around the convex portions 7, and fixed by thermocompression bonding or adhesive.

Therefore, the push buttons 8 are integrally fixed to the contact seat 3.

Further, on the lower surface of the adhesive point sheet 3, there are a plurality of circular movable contacts 9 corresponding to the push buttons 8.
are formed, and a spacer 10 surrounds these movable contacts 9.

The movable contacts 9 are formed into circular shapes by applying conductive paint such as carbon paste by screen printing.

The spacer 10 is formed by applying an elastic insulating material (paint) such as silicone rubber by screen printing to a thickness of about 100 μm, which is larger than the movable contact 9, and each movable contact 9... The contact sheet 3 is formed so as to cover the entire lower surface of the contact sheet 3, leaving a plurality of circular spaces 11 surrounding the periphery of the contact sheet 3 with a predetermined gap.

Further, on the upper surface of the circuit board 4, a plurality of fixed contacts 12 consisting of contact portions 12a and 12b are formed corresponding to each movable contact 9 of the contact sheet 3. , a circuit pattern connecting these fixed contacts 12 . . . is formed.

The upper case 1, the contact sheet 3, and the circuit board 4 are combined in a layered structure, and the push buttons 8 bonded to the upper surface of the contact sheet 3 are the same as the buttons imprinted on the upper case 1. They are fitted into the holes 6 so as to be movable up and down, facing each other.

In the push button switch device configured as described above, when the push button 8 is not pressed, the contact sheet 3 is stretched flat as shown in FIG. The movable contact 9 is spaced apart from the fixed contact 12 with a predetermined gap, and the push button 8 is pushed up by the contact sheet 3.

In this case, since the push button 8 is bonded to the contact sheet 3, it will not be pulled out from the button hole 6 even if it does not have a retaining flange.

When the push button 8 is pressed with a finger, the push button 8 descends within the button hole 6 as shown in FIG.
(the part surrounded by the blank part 11) is pressed down integrally, and the contact sheet 3 is elastically deformed downward along the periphery of the blank part 11.

Therefore, the movable contact 9 also descends.

When the push button 8 descends with a predetermined stroke, the movable contact 9 contacts the contact portion 12 of the fixed contact 12 formed on the circuit board 4.
a, contact on 12 b.

Note that when the pressing force is released, the contact sheet 3 returns to the tensioned state, and the push button 8 and movable contact 9 return to their original positions.

Therefore, this push button switch device has push button 8...
・ is adhered to the contact sheet 3.

When gluing the push buttons 8 to the contact sheet 3, first attach the protrusions 7 and the movable contacts 9 to the contact sheet 3.
. . . and the spacer 10, and then use a positioning jig to place the push buttons 8 on the convex portions 7 of the contact sheet 3. It is fixed by thermocompression bonding or adhesive.

Therefore, a large number of push buttons 8 can be fixed at once.

In addition, since the contact sheet 3 serves as a retainer for the push button 8, there is no need to form a flange, and the push button 8 acts as a simple rectangular parallelepiped, so the push button 8 is molded from synthetic resin. In this case, the structure of the mold is very simple and the manufacturing cost is low.

Furthermore, when assembling the upper case 1 and the contact sheet 3, push buttons 8 are placed on the contact sheet 3 in advance in correspondence with the button holes 6 of the upper case 1. Since they are glued together, simply by overlapping the upper case 1 and the contact sheet 3, the push buttons 6... directly and automatically open the button holes 6...
・It is fitted to.

For this reason, as in the past, push button 8... is replaced by button hole 6.
・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・
Positioning of push button 8... and push button 8...
Handling of the upper case 1 to prevent it from being pulled out from the button hole 6..., the push button 8... and the movable contact 9
Troublesome work such as positioning with... is no longer necessary.

In addition, by forming the convex portions 7 on the contact sheet 3, the convex portions 7 are connected to the movable contacts 9.
can be stably and uniformly supported and brought into contact with the fixed contacts 12.

By forming the spacer 10 on the contact sheet 3, the number of parts is reduced and the configuration becomes simpler than when the spacer 10 is provided separately.

Although the push button 3 is made of synthetic resin in the above embodiment, it may be formed by punching a metal plate.

Further, in the above embodiments, a separate spacer may be used by superposing it on the contact sheet.

This push button switch device can be applied to small electronic calculators and other electronic devices.

As explained above, in the push button switch device of the present invention, a convex portion is provided on the surface of a contact sheet made of a synthetic resin film provided with movable contacts, and a push button is integrally fixed onto this convex portion, so that the push button can be pressed. The assembly work of fitting into the hole can be performed very easily, and the manufacturing cost of the push button can be reduced.Moreover, when the push button is pressed, the convex part supports the movable contact stably and uniformly, making it possible to work with the fixed contact. By contacting them, chattering and double make can be prevented and a good switch operation can be performed, and the synthetic resin filter can be used to make the switch device thinner.

[Brief explanation of the drawing]

The drawings show one embodiment of the device of the present invention, in which Fig. 1 is an exploded perspective view, Fig. 2 is an enlarged sectional view of the contact sheet, and Fig. 3 is an exploded perspective view.
The figure is a cross-sectional view showing the non-operating state, and FIG. 4 is a cross-sectional view showing the operating state. 1... Upper case, 2... Lower case, 3... Contact sheet, 4... Circuit board, 6... Button hole, 7...Protrusion, 8...
...Push button, 9...Movable contact, 10...
・Spacer, 12...Fixed contact.

Claims (1)

[Scope of utility model registration request] A plurality of push buttons, a contact sheet made of a synthetic resin film having a convex portion on its surface corresponding to each of the push buttons and a movable contact on its back surface, and a fixed contact provided with a gap from the movable contacts. A push button switch device, comprising: the push button being fixed onto the convex portion.