JPH01213921A - 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 height with approaching the front of the electric apparatus concerned, and thereby allowing any key top to be pushed solely with certain performance. CONSTITUTION:In case a plurality of key switches are arranged closely to one another, the key tops 4, 5 are made with smaller heat height with approaching the front of the electric apparatus. That is, the middle key top 4 has shorter head than its upper key top 3, and the lower key top 5 in turn has a shorter head than the middle key top 4. Accordingly pushing of the middle key top 4 by a finger does not cause the conductive rubber 7 corresponding to the key top 5 to contact the printed circuit board, even though the push is strong or the finger is inclined greatly. 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] 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) glued 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. The device (1) receives the input 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 1] Conventional key switches are configured as described above, so 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 aims to provide a key switch for electrical equipment that allows only one key top to be reliably operated with a finger and prevents erroneous key operations from occurring.

[Means for Solving the Problems] A key switch for an electrical device according to the present invention is such that the height of the key top becomes lower as the key top is located lower (that is, in front) of the electrical device.

[Function] In the key switch for electrical equipment according to the present 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 cannot reach the printed circuit board. First, only input from the upper key top is reliably accepted.

[Example] Hereinafter, an example of the present invention will be described 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). Thus, as shown in Figure 2, when you press the middle key top (4) with your finger, even if you press it forcefully, tilt your finger greatly, or shift your finger downward, the key top middle (4) will not be pressed.
Since the lower key top (5) is shorter, the conductive rubber (7) corresponding to the lower key top (5) is the printed circuit board (8).
Do not come into contact with.

[Effects of the Invention] As described above, according to the present invention, since only - keys are operated reliably, there is an effect of eliminating malfunctions such as setting input.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a key switch for an electrical device according to an embodiment of the present invention, FIG. 2 is a schematic diagram of its operation, and FIG. 3 is a perspective view of an example of an electrical device having a conventional key switch.
FIG. 4 is a sectional view of the key switch section, and FIGS. 5 and 6 are schematic diagrams of its operation. 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, and (8) is a printed circuit board. In addition, in the figures, the same reference numerals indicate the same or equivalent parts. Agent Patent Attorney Masuo Oiwa Figure 1 7 ゝa No. 3 ≦ 3t5 No. 5

Claims (1)

[Claims] (1) A key switch for an electrical device, which is characterized in that, in a small electrical device in which a plurality of key switches are arranged close to each other, the height of the key top is lowered toward the front of the electrical device.