JP2001222928A - Membrane keyboard - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a membrane keyboard capable of preventing an arm bar from generating unnatural noise and from moving dull when a key-top is pressed down/opened. SOLUTION: A bending space 10 for bending a membrane sheet 8 is formed on the membrane sheet 8 corresponding to the abutting part of the ends 5b and 5c of the arm bar 5 to the membrane 8 so that vibrations of the arm bar 5, the source of unnatural noise, are absorbed in the membrane sheet 8, or so that dispersion in the diameter of the bar in production or of an inverted-L shaped arm bar guide 6, which is the cause of dull movement to the arm bar 5, is absorbed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a sliding structure of an arm bar of a membrane keyboard used for, for example, a personal computer.

[0002]

2. Description of the Related Art Conventionally, a membrane keyboard used for a personal computer or the like has a substantially U-shape, a bar main body is axially supported in the longitudinal direction of a key top, and the ends are respectively pressed when the key top is pressed. Some include an arm bar that slides on a sheet to prevent the key top from tilting.

The end of the arm bar is engaged with an inverted L-shaped arm bar guide protruding above the membrane sheet, and slides on the membrane sheet along the arm bar guide when the keytop is pressed.

[0004]

In a conventional membrane keyboard, the arm bar guide and the membrane sheet are compared with the bar diameter due to the variation of the bar diameter at the time of manufacturing the arm bar and the variation of the inverted L-shaped arm bar guide. If the gap between the arm bar is large, a gap is created between the end of the arm bar and the arm bar guide, and when the key top is pressed / released, the arm bar vibrates and generates abnormal noise when it comes into contact with the arm bar guide. There is a problem of giving discomfort to the elderly.

Conversely, if the gap between the arm bar guide and the membrane sheet is narrower than the bar diameter, the end of the arm bar slides on the surface of the membrane sheet when the keytop is pressed, so that the movement of the arm bar is reduced. There is a problem that the keytop is pressed down and the force to press the keytop is increased, and the keytop cannot be returned at worst.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a membrane keyboard which can prevent the arm bar from generating abnormal noise when the key top is pressed / released, and can prevent the movement of the arm bar.

[0007]

In order to achieve the above object, in the membrane keyboard of the present invention, a bending space is provided in the membrane sheet corresponding to the contact portion between the end of the arm bar and the membrane sheet.

[0008]

Embodiments of the present invention will be described with reference to the drawings. Elements common to the drawings are denoted by the same reference numerals.

FIG. 1 is a perspective view of a key switch with an arm bar of a membrane keyboard according to an embodiment of the present invention.
FIG. 2 shows the key switch A- with the arm bar shown in FIG.
FIG. 3 is an enlarged cross-sectional view of an end portion of the arm bar.

A key switch 1 with an arm bar includes a key top 2, a cup rubber 3, an actuator 4, an arm bar 5,
It comprises an arm bar guide 6, a key switch holder 7, a membrane sheet 8, and a reinforcing plate 9.

The membrane sheet 8 includes an upper sheet portion 8a,
The upper sheet portion 8a and the lower sheet portion 8c have flexibility. The spacer portion 8b and the lower sheet portion 8c are provided.

Electrodes 8c and 8d are printed and formed on the upper sheet portion 8a and the lower sheet portion 8b so as to face each other.
When the key is pressed, the cup rubber 3 presses the upper sheet portion 8a, the upper sheet portion 8a bends and the two electrodes come into contact, and the key switch 1 is turned on.

The arm bar 5 has a substantially U-shape. The main body 5a is rotatably supported on the back side of the key top 2 in parallel with the longitudinal direction of the key top 2 and ends 5b and 5c. Each is rotatably supported by an inverted L-shaped arm bar guide 6 protruding from the membrane sheet 8 and is in contact with the upper sheet portion 8a.

When the key top is depressed, the arm bar 5 acts so that the key top 2 is parallel to the membrane sheet 8 so as to smoothly press the key top 2 having a long shape.

At the contact portion between the end portions 5b and 5c of the arm bar 5 and the membrane sheet 8, a spacer 8b is removed in a long hole shape, and as shown in FIG.
A space 10 (hereinafter referred to as a flexure space 10) is provided inside the membrane sheet 8 so that the upper sheet portion 8a flexes when c slides on the membrane sheet surface in the direction of arrow B.

Next, the operation will be described. Key top 2
When the button is pressed, the ends 5b and 5c of the arm bar 5 deflect the upper sheet portion 8a into the bending space 10, and rotate smoothly while sliding in the direction of arrow B.

When the key top is released, the membrane sheet 8 is sandwiched between the upper sheet portion 8a of the membrane sheet 8 and the arm bar guide 6, and rotates while sliding in the direction of arrow C.

Therefore, the gap between the membrane sheet 8 and the arm bar guide 6 is larger than the diameter of the end portions 5b and 5c of the arm bar 5, and when the key top is pressed / released, the arm bar 5 is pressed.
Even if the end portions 5b and 5c vibrate between the membrane sheet 8 and the arm bar guide 6, the membrane sheet 8 bends into the bending space 10 to absorb the vibration of the arm bar 5.
It is possible to prevent the arm bar 5 from generating abnormal noise.

The gap between the membrane sheet 8 and the arm bar guide 6 is smaller than the diameter of the end portions 5b and 5c of the arm bar 5, and when the key top 2 is pressed / released, the arm bar 5
When the ends 5b and 5c of the arm bar 5 slide on the surface of the membrane sheet 8 and the movement of the arm bar 5 becomes tight between the membrane sheet 8 and the arm bar guide 6, the membrane sheet 8 bends into the bending space 10, In addition, it is possible to prevent the key top 2 from being returned due to the bitterness.

In this embodiment, the space is provided in the spacer portion of the membrane sheet. However, when the spacer portion of the membrane sheet is a polyester film, the space is provided corresponding to the contact portion between the end of the arm bar and the membrane sheet. Is provided. Further, when the spacer portion is replaced by resist printing for printing on the upper sheet portion and the lower sheet portion, it can be realized by deleting the printing of the portion corresponding to the contact portion between the end portion of the arm bar and the membrane sheet.

[0021]

Since the present invention is configured as described above, it has the following effects.

By providing a flexure space in the membrane sheet corresponding to the contact portion between the end of the arm bar and the membrane sheet, the gap between the membrane sheet and the arm bar guide is wider than the arm bar diameter, and the key top is pressed / released. Sometimes, even if the arm bar vibrates between the membrane sheet and the arm bar guide, the membrane sheet absorbs the vibration of the arm bar, so that the vibration of the arm bar, which causes abnormal noise when the keytop is pressed / released, can be prevented. .

[0023] Further, by providing a bending space in the membrane sheet corresponding to the contact portion between the end portion of the arm bar and the membrane sheet, the gap between the membrane sheet and the arm bar guide is smaller than the diameter of the arm bar, and the key top is pressed. When the end of the arm bar slides on the surface of the membrane sheet at the time of opening, even if the movement of the arm bar is tight between the membrane sheet and the arm bar guide, the key top is bent because the membrane sheet is bent into the bending space. It can move smoothly.

[Brief description of the drawings]

FIG. 1 is a perspective view of a key switch with an arm bar.

FIG. 2 is a sectional view taken along the line AA of FIG. 1;

FIG. 3 is an enlarged sectional view of an end of an arm bar.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Key switch 8 Membrane sheet 10 Flexure space

Claims (2)

[Claims] 1. A substantially U-shaped bar main body is axially supported in the longitudinal direction of a key top, and when the key top is depressed, the ends are respectively slid on the membrane sheet to prevent the key top from tilting. A membrane keyboard having an arm bar, wherein a flexible space is provided in the membrane sheet corresponding to a contact portion between an end of the arm bar and the membrane sheet. 2. The membrane sheet includes an upper sheet portion and a lower sheet portion having contact points corresponding to the pressed position of the key top, and a spacer portion sandwiched between the two sheet portions and having the bending space. The membrane keyboard according to claim 1.