JPH10188731A - Keyboard switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a keyboard switch having a good, stable operating feel. SOLUTION: A projection 11 is formed on the top surface of a dome rubber 5 which turns on and off a contact in the contact part of a membrane sheet 2 when pressed by the pressing part 6A of one (6) of a pair of link members 6, 7 supporting a key top in a pantograph mechanism, and a round hole 12 accommodating and positioning the projection 11 is formed in the pressing part 6A of the link member 6. The pressing part 6A and the rubber 5 are prevented from moving relative to each other, thereby deforming the rubber 5 into a good, stable state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a keyboard switch which can be used for various devices such as a personal computer and a word processor, and more particularly to a keyboard switch having a key top supported by a pantograph mechanism.

[0002]

2. Description of the Related Art FIG. 4 shows an example of a conventionally proposed keyboard switch having this kind of configuration. A membrane sheet 2 is laminated on a substrate 1 constituting a keyboard. As shown in FIG. 5, the membrane sheet 2 is formed by laminating and integrating two insulating sheets 2A and 2B at a predetermined interval by a spacer 2C and forming conductive patterns 2D and 2E on their opposing surfaces. Thus, a contact is formed by the conductive patterns 2D and 2E. In this contact portion, when the insulating sheet 2A is pressed from above, the conductive patterns 2D and 2E come into contact with each other, whereby a contact signal is obtained.

A housing 3 made of an insulating resin material or the like is stacked and mounted on the membrane sheet 2. A hole 4 (see FIG. 5) facing the contact portion is formed in the housing 3 to expose the contact portion of the membrane sheet 2, and a dome-shaped rubber 5 is formed on the membrane sheet 2 at the hole 4. Be placed. The dome-shaped rubber 5 is composed of a skirt portion 5A that can be bent in a vertical direction as shown in a cross section in FIG. 5, and a push button portion 5B attached to an upper portion of the skirt portion 5A. 2 is attached, for example, by bonding. In addition, 5C shows a notch for air release.

A pair of link members 6 and 7 constituting a pantograph mechanism are configured as shown in FIGS.
The link member 6 has a pressing portion 6A for pressing the rubber 5 at the center.
And the other link member 7 is provided on both side surfaces of the pressing portion 6A.
The hole 6B which engages with the pair of shafts 7A formed in each is formed. The shaft 7A of the link member 7 is
The link members 6 and 7 are combined in an X-shape by being engaged with the hole 6B, that is, rotatably connected to each other at an intermediate portion.

The link member 6 has a pair of shafts 6C projecting inward at one end thereof and a shaft 6D projecting outwardly at the other end thereof. On the other hand, a shaft 7B is formed so as to extend over one end of the link member 7, and a pair of shafts 7C protrudes outward at the other end. As shown in FIG. 4, the shaft 7B is engaged with a rotating bearing 8A provided on the back surface of the keytop 8, while the shaft 6D is engaged with a rotating bearing 3A formed on the housing 3, and these shafts 7B And 6D are rotatably supported. On the other hand, the shaft 6C has a sliding groove 8 formed on the back side of the key top 8.
B, the shaft 7C is engaged with the sliding groove 3B formed in the housing 3. In this state, the pressing portion 6A of the link member 6 comes into contact with the top surface of the push button portion 5B of the rubber 5, and the link members 6 and 7 are held in an upright state by the elastic return force of the rubber 5, that is, the key top 8 is It is held at the top dead center position.

The link member 6 is provided with a pair of stoppers 6E as shown in FIG. 6 so as not to overlap with each other when the link member 7 is assembled. A concave portion 6F is formed on the surface opposite to the surface in contact with the surface as a relief for the meat for weight reduction. When the key top 8 is pressed down, the link members 6 and 7 forming the pantograph mechanism are displaced in a direction approaching the surface of the housing 3, and the key top 8 moves substantially parallel to the surface of the housing 3. At this time, the pressing portion 6A formed on the link member 6 presses and crushes the rubber 5, whereby the contact portion of the membrane sheet 2 is pressed by the push button portion 5B, and the contact is turned on.
It is turned off.

[0007]

In this type of keyboard switch, there is a strong demand for a small and thin keyboard switch, and a small and thin keyboard switch having a good operational feeling is desired. The operational feeling depends on the deformation state of the rubber 5 when the key top 8 is pressed down, that is, when one keyboard switch is viewed, the rubber 5 deforms as desired, and the rubber 5 is deformed between the keyboard switches. It is important that there is no variation in the deformation.

However, in the above-described conventional keyboard switch, the pressing portion 6A of the link member 6 and the top surface of the push button portion 5B of the rubber 5 are merely in contact with each other. For example, as shown in FIG. 8, there is a possibility that the pressing portion 6A is displaced from the rubber 5 in the direction of the contact surface thereof and assembled. The displacement during the assembly causes an unexpected deformation of the rubber 5, and the rubber 5 caused by the pressing operation.
In particular, in the case of the small rubber 5 of the small keyboard switch, the influence of the positional shift is large, and the operational feeling is deteriorated and the variation is greatly caused.

In view of the above problems, an object of the present invention is to provide
An object of the present invention is to provide a keyboard switch capable of obtaining a good and stable operation feeling.

[0010]

According to the present invention, a hole is provided on a membrane sheet for exposing a contact portion formed on the membrane sheet, and a key top is supported on a peripheral edge of the hole. And a housing having an engaging portion for engaging with a pair of link members, one end of which is engaged with the engaging portion, and which is rotatably connected to each other at an intermediate portion, and each other end of which is a back surface of the key top. A pair of link members that support the key top by forming a pantograph mechanism so that the key top moves substantially parallel to the surface of the housing,
Attached on the membrane sheet exposed in the hole,
A keyboard switch having a dome-shaped rubber that is pressed by one of a pair of link members by pressing a key top to turn on and off the contacts of the contact portion, wherein the rubber is pressed by one of the link members. A projection is integrally formed on the surface of the link member, and a hole for receiving and positioning the projection is formed in one of the link members.

[0011]

Embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 shows an embodiment of the present invention, and FIG. 2 shows a main part thereof. 4 to 7 are denoted by the same reference numerals, and description thereof will be omitted.

In this example, a projection 11 is provided at the center of the top surface of the push button portion 5B of the dome-shaped rubber 5 which is pressed by the pressing portion 6A of the link member 6. The protrusion 11 is formed integrally with the rubber 5, and in this example, has a cylindrical shape having a spherical end. On the other hand, the protrusion 11 of the pressing portion 6A of the link member 6
A round hole 12 is formed in a position facing the above.

Therefore, when the link members 6 and 7 are assembled, the protrusion 11 of the rubber 5 is accommodated and positioned in the round hole 12, thereby preventing the pressing portion 6A and the rubber 5 from being displaced in the contact surface direction. Is done. FIG. 3 shows the configuration of the link member 6. The round hole 12 also serves as an escape of meat for reducing the weight of the pressing portion 6A.

In this example, as shown in FIGS. 1 and 2, a minute projection 13 protruding in the direction of the contact portion of the membrane sheet 2 is integrally formed at the center of the inner surface of the push button portion 5B of the rubber 5. In addition, a good operational feeling and a desired stroke (ON follow) after the contact is turned on can be ensured even in the case of thinning.

[0015]

As described above, according to the present invention, it is possible to prevent the dome-shaped rubber 5 from being displaced from the pressing portion 6A of the link member 6 that presses the dome-shaped rubber 5, so that it is small and thin. A keyboard switch having a good and stable operation feeling can be realized.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view showing a main part of one embodiment of the present invention.

FIG. 3 is a perspective view showing a configuration of a link member 6 in FIG.

FIG. 4 is a sectional view showing a conventional keyboard switch.

FIG. 5 is a diagram for explaining the configuration of the membrane sheet and the state of attachment of rubber.

6A is a perspective view showing a configuration of a link member 6 in FIG. 4, and FIG.

FIG. 7 is a perspective view showing a configuration of a link member 7 in FIG. 4;

FIG. 8 is a view for explaining positional displacement between a link member and rubber.

Claims (1)

[Claims] 1. A hole mounted on a membrane sheet for exposing a contact portion formed on the membrane sheet, and a pair of link members for supporting a key top are engaged with a periphery of the hole. A housing having an engaging portion, one end of which is engaged with the engaging portion, the other end of which is rotatably connected to an intermediate portion of the housing, and the other end of which is engaged with the back surface of the key top; A pair of link members that support the key top by forming a pantograph mechanism so as to move substantially in parallel with the surface of the housing, and are mounted on the membrane sheet exposed to the hole, and the key top is pressed by the pressing operation of the key top. A keyboard switch comprising a dome-shaped rubber that is pressed by one of the pair of link members to turn on and off the contacts of the contact portion; A keyboard switch, wherein a protrusion is integrally formed on a surface pressed by one of the members, and a hole for receiving and positioning the protrusion is formed in one of the link members.