JPH01213922A - Key switch of small-sized electric apparatus - Google Patents

Abstract

PURPOSE:To prevent misoperation in key entry by forming the keys in such an arrangement that they have smaller tallness with approaching the front of the electric apparatus concerned, furnishing a boss on the panel adjoining to each key top, and thereby allowing any key top to be pushed solely with certain performance. CONSTITUTION:The key tops 4, 5 are made with smaller tallness with approaching the front of the electric apparatus, and a boss 9 with appropriate tallness is provided on the outer side-face of the panel 10 penetrated by the key tops 3-5 in such a position as adjoining to each key top 3-5 in order the push-in strength to be equal at the time of operation. Accordingly eventual pushing of two tops 4, 5 by one finger does not cause the conductive rubber corresponding to the lower one 5 to reach the printed circuit board 8, and entry through the upper one 4 is solely achieved certainly. The key with longer key top is prevented from excessive depression by means of the boss 9 provided on the panel 10. Thus only one intended key is pushed certainly to eliminate risk of mishandling in entering the settings, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to the structure of a key switch that is pressed when setting a small electrical device such as a time switch.

[Prior Art 1] Conventionally, there are structures of this type of key switch as shown in FIGS. 3 to 6. In the figure, (1) is electrical equipment,
(2) is a display section that displays program contents, time, etc.; (3) is on the key top; (4) is in the key top; (5) is on the key top.
) is the bottom of the key top, (6) is a rubber switch made of insulating rubber and has an elastic force that pushes up the top of the key top (3), the middle of the key top (4), and the bottom of the key top (5).
7) is a conductive rubber glued to the rubber switch (6), (
8) is a printed circuit board having a structure in which different polarity patterns approach each other on the surface facing the conductive rubber, and the different polarity patterns are short-circuited by contact with the conductive rubber (7).

Next, the operation will be explained. For example, as shown in Figure 5,
When you press the middle key top (4) with your finger, the key top middle (4)
The rubber switch (6), which was in contact with the bottom of the key top (4) and pushing it up, is pushed down by the key top (4). The conductive rubber (7) adhered to this rubber switch (6) comes into contact with the printed circuit board (8), and the different polarity patterns on the printed circuit board (8) are short-circuited. Through the above operations, the device (1) receives the input from the key top (4) and displays its contents on the display section (2).

By the way, as shown in Figure 6, if you press your finger strongly,
If you press with your finger at a large angle or shift your finger downwards, when you press the middle key top (4), you will also press the bottom key top (5) at the same time, and the conductive rubber corresponding to the bottom key top (5) will be printed. It may also come into contact with the substrate (8).

In addition, when pressing the middle key top (4), press the top key top (3).
) is not ergonomic.

[Problem to be solved by the invention] Since the conventional key switch is configured as described above, unless the inclination, position, strength, etc. of the finger when pressing the key tops are specified, two key tops will operate at the same time. However, there was a problem in that the key force was mistakenly accepted for two pieces.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to obtain a key switch for an electric device that allows only one key top to be reliably operated with a finger and that does not cause erroneous key operations.

[Means for Solving the Problems] In the key switch for electrical equipment according to the present invention, the top surface of each key top is lowered toward the bottom (that is, toward the front) of the equipment, and accordingly, when the key switch is operated, In order to prevent the pressing force of the key switch from changing, a protrusion is provided on the device board adjacent to the key top.

[Effect]

In the key switch for electrical equipment in this invention, even if you press the top and bottom two key tops with your finger, the bottom key top is shorter, so the conductive rubber corresponding to the bottom key top does not reach the printed circuit board, and the top Reliably accepts input only from the key tops. In addition, keys with long key tops are prevented from being pressed too much by the protrusion provided on the device board.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In FIGS. 2 to 2, (3) to (8) are the same as the conventional one. However, the middle key top (4) is on the key top (
3) The height of the head is lower. Furthermore, the lower key top (5) has a lower head height than the middle key top (4). (9) is a convex part provided on the device board (10) so as to surround the top and side surfaces of the key top top (3) and key top middle (4), and the length from the top surface of the key top to the top surface of the convex part. This is done so that the values are equal.

Thus, as shown in Figure 2, when pressing the middle key top (4) with your finger, even if you press it forcefully, tilt your finger greatly, or shift your finger downwards, the key top will be lower than the middle key top (4). (5) is shorter, so below the key top (5)
The conductive rubber (7) that is compatible with Do not apply excessive load.

〔Effect of the invention〕

As described above, according to the present invention, only - keys are operated reliably, which has the effect of preventing erroneous operations such as setting input, and also has the effect of preventing damage to keys and equipment due to excessive key presses. There is.

[Brief explanation of the drawing]

FIG. 1(a) is a sectional view showing a key switch for an electrical device according to an embodiment of the present invention, FIG. 1(b) is a top view thereof,
Fig. 2 is a schematic diagram of its operation, Fig. 3 is a perspective view of an example of an electric device having a conventional key switch, Fig. 4 is a sectional view of the key switch section, and Figs. 5 and 6 are an outline of its operation. It is a diagram. In the figure, (1) is the electrical equipment, (2) is the display, and (3)
is above the key top, (4) is inside the key top, (5) is below the key top, (6) is a rubber switch, (7) is a conductive rubber, (8) is a printed circuit board, and (9) is a convex part. . In addition, in the figures, the same reference numerals indicate the same or equivalent parts. Agent: Masuo Oiwa, Patent Attorney (b no. 10 no. 1\ Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] (1) In small electrical devices with multiple key switches placed close together, the key tops are designed to lower the height of the key tops closer to the front of the electrical device and to equalize the pressing force during operation. A key switch for electrical equipment, characterized in that a protrusion of an appropriate height is provided adjacent to the key top on the outer surface of the equipment board through which the key switch passes.