JPH09259694A - Keyboard - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a keyboard of sure switch action, which can perform reduction of a cost, thinning of a type and lightening of weight by decreasing a number of part items, by integrally forming a holding plate and chassis, also integrally forming even a positioning/fixing fastening member of a membrane switch, made into a molded chassis. SOLUTION: A hole 11B of a membrane switch(MSW) 11 is fitted to a boss 12B integrally formed in a plane part 12A of a molded chassis 12, the MSW11 is positioned and fixed. A cup-shaped rubber(CR) 15 is fitted to a root part of upper protruded part 12E integrally formed on the plane part 12A. Next, a columnar part 14N of a push button 14 is inserted to center through hole 12F, the push button 14 is elastically supported on an upper cylinder part 15C of the CR15. When the push button 14 is pressed down, the CR15 is deflected, a pressing protrusion 14D of the push button 14 turns on a plurality of switch contact parts 11A through a protrusion part 15E of the CR15. In this way, a keyboard of sure switch operation, which can perform reduction of the cost, thinning and lightening of weight by decreasing a number of part items, is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a keyboard used as an input device for personal computers, word processors and the like.

[0002]

2. Description of the Related Art A conventional keyboard will be described with reference to FIGS.

FIG. 3 is a perspective view of a keyboard, and FIG. 4 is a cross-sectional view of a push button switch constituting the keyboard. In FIG. 3, 1 is a metal plate holding plate, 2 is a molded resin chassis, The membrane switch 3 placed on the plate 1 is sandwiched between the rib 2A of the chassis 2 and fixed by a fastening member 4 such as a screw.

On the other hand, the push button 5 is inserted in the through hole 2B of the chassis 2.
The columnar portion 5A is held so as to be slidable in the vertical direction, and the dome-shaped rubber 6 arranged below the columnar portion 5A is provided with a projection 6A for pushing the push-type switch contact portion 3A of the membrane switch 3. It projects downward.

The operation of the push-button switch is constituted so that the dome-shaped rubber 6 is compressed by pushing down the push-button 5 and the projection 6A is turned on by pressing the switch contact 3A of the membrane switch 3. It is a thing.

[0006]

However, in recent years, input devices for driving electronic switch circuits in electronic equipment, information equipment, etc. have been required to be low in price and thin and light in weight. In such a conventional keyboard, since the membrane switch 3 is sandwiched between the holding plate 1 and the chassis 2 which are separate members and fixed with the fastening member 4, the material cost and the assembly cost are high. However, there is a problem that it is difficult to reduce the thickness and weight of the entire keyboard.

The present invention is intended to solve such a conventional problem, and an object thereof is to provide a keyboard which can be made thin and lightweight while reducing the number of constituent parts to reduce the cost.

[0008]

In order to solve the above-mentioned problems, the keyboard according to the present invention has a structure in which a holding plate and a chassis are integrated to form a molded resin chassis, and a fastening member for a membrane switch is also integrated. Is.

According to the present invention, a holding plate made of a metal plate and a fastening member are not required, and a low-priced, thin and lightweight keyboard can be realized.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is a membrane switch having a push-type switch contact portion, a flat surface portion on which a membrane switch is mounted, and an upward protruding portion having a through hole in the center. With a molded chassis consisting of, and cylindrical portions above and below the intermediate flat surface portion, and a protrusion for pressing the switch contact portion on the lower surface near the outer periphery of the flat surface portion
It consists of a cup-shaped rubber that is positioned by fitting the central hole into the upper protruding portion of the molded chassis, and a columnar portion of the upper pressing surface and the central lower surface thereof, and the columnar portion is formed by the through hole of the upper protruding portion of the molded chassis. It is configured to consist of a push button that is held so that it can slide in the vertical direction, is placed on the upper end of the upper cylindrical portion of the cup-shaped rubber, and has a protrusion that presses the upper surface of the protrusion for pressing the switch contact portion on the lower surface of the flat portion. The present invention has the effects of reducing the cost with a small number of components and realizing a thin and lightweight keyboard.

According to a second aspect of the present invention, in the first aspect of the present invention, a plurality of switch contact portions connected in parallel are provided at symmetrical positions with respect to the center of the through hole of the upper protruding portion of the molded chassis. The switch contact part pressing projection and the projection for pressing the back surface of the switch contact part pressing projection are arranged corresponding to the membrane switch, the cup-shaped rubber and the push button, respectively. Even if the position of pressing the surface is not the center of the pressing surface
It has the effect of becoming N.

According to a third aspect of the present invention, in the first or second aspect of the present invention, the membrane switch is fitted in a boss with a retaining claw integrally provided on a flat surface portion of the molded chassis, whereby the membrane switch is fitted. The position of the membrane switch can be regulated and floating can be prevented without adding a positioning component.

According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, with a retaining claw integrally formed by being connected to an end of the flat surface portion of the molded chassis by a thin portion for hinge. A fixing member and a fixing means composed of an engaging hole provided in a flat portion at a position where the fixing member is folded back at a thin portion is configured to prevent the membrane switch from being lifted up. This has the effect of preventing the membrane switch from rising without adding another component.

FIG. 1 shows an embodiment of the present invention.
And it demonstrates using FIG. FIG. 1 is a cross-sectional view of a push button switch constituting a keyboard according to the same embodiment,
In the figure, 11 is a membrane switch having a push-type switch contact portion 11A, 12 is a molded chassis made of molded resin, and a boss 12B with a retaining claw integrally provided on the flat surface 12A of the molded chassis 12 is a membrane. By fitting in the hole 11B of the switch 11, the position of the membrane switch 11 with respect to the molded chassis 12 is prevented and the membrane switch 11 is prevented from rising.

At the end of the molded chassis 12, as shown in FIGS. 2 (a) and 2 (b), a retaining claw 13A integrally formed with the molded chassis 12 by being connected by a thin hinge portion 12C. The attached fixing member 13 is folded back at the thin portion 12C, and the retaining claw 13A is attached to the membrane switch 1
1 through the square hole 11C of the molded chassis 12 and the square hole 12D of the molded chassis 12 to engage with each other.
1 is firmly fixed to the molded chassis 12, and this structure is particularly effective in the tail take-out portion of the membrane switch.

The flat portion 12A of the molded chassis on which the membrane switch 11 is mounted is provided with an upward projecting portion 12E at a position where the push button 14 is arranged, and the cup-shaped rubber 15 is provided at the base of the upward projecting portion 12E. Is the central hole 1
It is positioned by fitting 5A.

The cup-shaped rubber 15 has cylindrical portions 15C and 15D above and below the intermediate plane portion 15B.
A protrusion 15E for pressing the switch contact portion 11A is provided on the lower surface near the outer periphery of the switch.

A push button 14 made of molding resin is disposed above the cup-shaped rubber 15, and a columnar portion 14B provided at the center of the lower surface of the pressing surface 14A penetrates the upper protrusion 12E of the molding chassis 12 through the center. Fitted and held by the hole 12F so as to be slidable in the vertical direction, and at the lower end 1 of the outer peripheral portion.
4C is placed on the upper end of the cup-shaped rubber 15, and a downward pressing protrusion 14D is provided at a position corresponding to the lower protrusion 15E of the cup-shaped rubber 15.

The switch contact portion 11A of the membrane switch 11 and the protruding portion 1 below the cup-shaped rubber 15 are provided.
5E and the projection 14D for pressing of the push button 14 are combined with each other.
A plurality of sets of switch contact portions 11 are provided at positions symmetrical with respect to the center of the central through hole 12F of the upper protruding portion 12E of the molded chassis 12 that fits and holds the four columnar portions 14B.
A is electrically connected in parallel.

The operation of the push button switch that constitutes the keyboard according to the present embodiment having the above-described structure is as follows.
By pressing the pressing surface 14A of 4, the lower end 14C of the outer peripheral portion presses and deforms the upper cylindrical portion 15C of the cup-shaped rubber 15, and the pressing protrusion 14D of the push button 14 hits the intermediate flat surface portion 15B of the cup-shaped rubber 15 and moves downward. By pushing down, the lower cylindrical portion 15D is deformed, and the intermediate flat surface portion 15
The protrusion 15E on the lower surface of B pushes the switch contact portion 11A of the membrane switch 11 to turn it on.

At this time, the position where the pressing surface 14A of the push button 14 is pressed is not the center of the pressing surface 14A but is a biased position, and even if the push button is slightly tilted, the position is such that it will be pressed in the plurality of switch contact portions 11A. The closest switch contact is O
Therefore, the switch operation is surely performed.

[0022]

As described above, according to the present invention, a molded chassis is formed by integrally forming a holding plate made of a metal plate and a chassis made of a molded resin and also a member for positioning and fixing the membrane switch. Thus, a holding plate and a fastening member made of a metal plate are not required, and a keyboard that can be made thin and lightweight at a low price and has a reliable switch operation can be obtained, which has a great practical effect.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a push button switch that constitutes a keyboard according to an embodiment of the present invention.

FIG. 2A is a perspective view of a main part for explaining a method of fixing the membrane switch to a molded chassis. FIG. 2B is a side view of the same.

FIG. 3 is a perspective view of a conventional keyboard

FIG. 4 is a sectional view of a push button switch that constitutes the keyboard.

[Explanation of symbols]

 11 Membrane switch 11A Switch contact part 11B hole 12 Molded chassis 12A Flat part 12B Boss 12C Thin part for hinge 12D Square hole 12E Upper protruding part 12F Central through hole 13 Fixing member 13A Locking claw 14 Push button 14A Push face 14B Column part 14C Lower end of outer peripheral portion 14D Protrusion for pressing 15 Cup-shaped rubber 15A Central hole 15B Intermediate flat surface portion 15C Upper cylindrical portion 15D Lower cylindrical portion 15E Projection portion

Claims (4)

[Claims] 1. A membrane switch having a push-type switch contact portion, a molded chassis composed of a flat surface portion on which the membrane switch is placed and an upward protruding portion having a through hole in the center, and cylindrical portions above and below the intermediate flat surface portion. And a projection for pressing the switch contact portion on the lower surface near the outer periphery of the flat portion, and a cup-shaped rubber positioned by fitting the central hole into the upward projection of the molded chassis, and the upper pressing surface and It is composed of a columnar portion on the lower surface of the center, and the columnar portion is held by the through hole of the upper protruding portion of the molding chassis so as to be slidable in the vertical direction and placed on the upper end of the upper cylindrical portion of the cup-shaped rubber, and the lower surface of the flat portion Of a push button having a protrusion for pressing the upper surface of a protrusion for pressing the switch contact portion. 2. A plurality of sets of switch contact parts connected in parallel, a switch contact part pressing protrusion, and a switch contact part pressing part at positions symmetrical with respect to the center of the through hole of the upper protruding part of the molded chassis. The keyboard according to claim 1, wherein protrusions for pressing the back surface of the protrusions are arranged corresponding to the membrane switch, the cup-shaped rubber, and the push button, respectively. 3. The keyboard according to claim 1, wherein the membrane switch is positioned by fitting a hole of the membrane switch into a boss with a retaining claw integrally provided on a flat surface portion of the molded chassis. 4. A retaining member with a retaining claw integrally formed by connecting a thin portion for hinge to an end portion of the flat portion of the molded chassis, and the fixing member is provided on the flat portion at a position where the thin portion is folded back. The keyboard according to any one of claims 1 to 3, wherein the membrane switch is prevented from being lifted up by the fixing means formed of the engaging hole.