JPS6012173Y2 - key button switch device - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a key button switch device for a small electronic calculator or the like.

In recent years, small electronic calculators have become smaller and thinner, and in order to make switch devices for manual key operation thinner, for example, a conductive agent is applied to the back side of a sheet-shaped resin film, and this area is A so-called touch-type switch device has been developed in which input operation is performed by directly pressing a switch with a finger or the like to cause a fixed contact disposed at the bottom to conduct.

By the way, in the touch key type switch device, the position of each key is determined by printing a predetermined key name on a portion of each key on the top surface of a sheet-like resin film, without providing a separate key button. Therefore, when operating a key, you must visually check the position where the key name is printed on the flat surface and press it with your finger.

Therefore, the position of each key part cannot be confirmed by the tactile sense of the fingertips, but must be confirmed only visually, which is disadvantageous in that it is difficult to perform reliable operations.

Further, in the conventional key button switch device, a sheet-shaped insulating spacer is interposed between the movable contact and the fixed contact, which results in a large number of parts and poor assembly efficiency.

This idea was created in view of the above circumstances, and its purpose is to make it possible to confirm the key part using the tactile sensation of the fingertips, thereby enabling reliable key operation, and to reduce the number of parts. An object of the present invention is to provide a thin key button switch device that can improve assembly efficiency.

An embodiment of this invention will be described below with reference to FIGS. 1 to 4.

Reference numeral 1 in the figure is an upper main body case of a small electronic calculator, and in its predetermined position there is a window 1a large enough to expose almost the entire surface of the contact sheet 2, and a window 1b large enough to expose a display device (not shown). is cut out.

The contact sheet 2 is formed of a resin film made of polyethylene, polyimide, etc. and has a thickness of about 50/A,
A plurality of key buttons 3 are formed on its surface.

Each key button 3 is formed by thick film screen printing of resin paint such as silicone rubber to a thickness of about 20oP, and each key button 3 is formed higher than the surface of the contact sheet 2, so that It can be recognized by the tactile sensation of the fingertips.

A key name 4 is printed on the surface of each key button 3.

Further, on the back surface of the contact sheet 2, movable contacts 5 are printed and formed using conductive paint such as conductive carbon at positions corresponding to the respective key buttons 3, as shown in FIG.

Each movable contact 5 is surrounded by a predetermined distance apart, and a spacer 6 is attached to the contact sheet 2 using an insulating paint such as silicone rubber.
The thickness is less than the thickness of the movable contact 5 over the entire back surface of the
It is formed by screen printing to a thickness of about 00μ.

A printed circuit board 7 formed in the same shape as the contact sheet 2 is laminated below the contact sheet 2.

On the surface of this printed circuit board 7, fixed contacts 8 consisting of a pair of fixed contacts 8a and 8b are formed at positions corresponding to each of the movable contacts 5, and each fixed contact 8 has a predetermined printed wiring. It has been subjected.

Thus, the contact sheet 2 and the printed circuit board 7 are housed in the lower case 9 and are enclosed by the upper case 1 and the lower case 1.

Next, the operation of the key button switch device constructed as described above will be explained with reference to FIG. 3.

When the key button 3 is not operated, due to the thickness of the spacer 6, the movable contact 5 and the fixed contact 8 face each other with a predetermined distance and are electrically isolated.

When the key button 3 is pressed after confirming the position of the key button 3 with a fingertip from this state, the contact sheet 2 is bent toward the printed circuit board 7, so that the movable contact 5 comes into contact with the fixed contact 8 and is electrically connected. 8 becomes conductive and key manual operation is performed.

That is, since the key button 3 is formed higher than the surface of the contact sheet 2, the position of the key button 3 can be confirmed by fingertips, and the key can be reliably pressed to perform manual key operation.

Furthermore, by forming the key button 3 with an elastic resin paint, the feeling of pressure when operating the key is improved, and the stable contact between the fixed contact 8 and the movable contact 5 prevents chattering. Connect.

When the pressing force of the fingertip is removed from the pressed state of the key button 3, the contact sheet 2 returns to its original state, and the movable contact 5 and the fixed contact 8 are again spaced apart for a predetermined period.

In the above embodiment, the key name 4 is printed on the surface of the key button 3, but the structure is not limited to this, and the contact sheet 2 is formed of a chromatic material as shown in FIG. At the same time, predetermined parts other than the numbers or symbols of the key name are printed on a thick film using a chromatic resin paint different from that of the contact sheet 2 to form the key button 3, so that the contact sheet 2 is used as the key name. The surface of the key button 3 may be exposed through the key button 3.

Furthermore, as shown in Figure 4, the key buttons 3 may be formed by printing the key names on the contact sheet 2 and printing a thick layer of transparent resin paint thereon. The operation is exactly the same as in the previous embodiment.

Furthermore, the contact sheet 2 may be formed of a rubber sheet.

Furthermore, in the above embodiment, a case was described in which this invention was applied to a small electronic calculator, but this invention is not limited to the above embodiment, and can be applied to electronic equipment using a thin key button switch device. can.

As explained above, according to the key button switch device of this invention, the key buttons are printed in a thick film with resin paint on the top surface of the contact sheet, so when operating the key buttons, the key buttons can be pressed by the touch of the fingertips. Since the position of the button can be confirmed, key operations can be performed reliably, improving operability.

In addition, since the key button is printed on a resin sheet, it can be manufactured at low cost, and since the key button and insulating spacer are integrally printed on the contact sheet, the number of parts is reduced. Assembly work is reduced.

Furthermore, since the key buttons can be easily formed into various shapes by thick film printing, they are also excellent in decorativeness.

[Brief explanation of the drawing]

Fig. 1 is an exploded perspective view showing one embodiment of the key button switch device of this invention, Fig. 2 is a partial perspective view showing the back side of the contact sheet of the same embodiment in detail, and Fig. 3 is an exploded perspective view of the key button switch device of the same embodiment. FIGS. 4a and 4b are partial sectional views showing other embodiments of the key button portion. 2...Contact sheet, 3...Key button, 4
...Tune key name, 5...Movable contact, 7...
...Printed circuit board, 8...Fixed contact.

Claims (1)

[Scope of utility model registration request] A contact sheet with movable contacts formed on the back surface, and fixed contacts provided with a gap corresponding to the movable contacts,
On the surface of the contact sheet, a key button is printed in a protruding manner with a resin material corresponding to the movable contact, and on the back surface of the contact sheet, an insulating spacer is printed around the movable contact to be thicker than the movable contact. A key button switch device formed by