JPS61292826A - Keyboard - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a keyboard used as an input device for electronic typewriters and various office automation equipment, and particularly to a keyboard provided with a membrane switch.

<Prior art> A keyboard using a membrane switch, in which a circuit pattern including electrodes is formed on the opposing surfaces of a pair of insulating films and a spacer is interposed between them, is used for input devices such as electronic typewriters and office automation equipment. ing.

This type of conventional key tote consists of an upper cover that supports a large number of keys in a vertically movable manner, a rubber spring that biases each key upward, and a support plate that supports the membrane switch from below. The rubber spring is fastened to the support plate at several locations using screws, and the support plate is fixed to the upper cover using screws.

<Problems to be Solved by the Invention> For this reason, when the membrane switch is screwed to the support plate at several locations, wrinkles and tension may occur in the membrane switch as the screws rotate, which may interfere with the switching operation of the electrodes. In view of the above-mentioned problems, the present invention has been made in view of the above-mentioned problems.The present invention has been made in view of the above-mentioned problems. An object of the present invention is to provide a keyboard 1 that can be assembled into a keyboard to prevent chattering, key-in delays, etc.

Means for Solving the Problems> In order to achieve the above object, the keyboard of the present invention has the following features:
A flat frame, a key supported movably in the vertical direction by the frame, a support plate fixed to the frame, a key placed on the support plate, and - on opposing surfaces of a pair of insulating films. A membrane switch formed with a circuit pattern including electrodes with a spacer interposed therebetween, a flat base part interposed between the membrane switch and the frame, and an inverted cup-shaped bulge part and a switch operating part at a position facing the key. The rubber spring is configured to sandwich the membrane switch between the upper surface of the support plate and the lower surface of the base of the rubber spring.

<Example> Embodiments of the present invention will be described below based on the drawings.

Fig. 1 shows an exploded perspective view of the keyboard of an electronic typewriter, Fig. 2 shows a lateral sectional view of the keyboard, Fig. 3 shows an enlarged sectional view of the key switch section, and Fig. 4 shows a frame l. A back view is shown.

The flat frame l that constitutes the upper cover of the keyboard is integrally molded from ABS resin, etc., and has a number of holes 9 in a predetermined arrangement into which key stems are inserted, and the surface has holes 9 around which the key stems can move up and down. Guide tube 2 that guides
is installed protrudingly. On the back side of the frame 1, as shown in FIG. 4, an annular pressing part 3 is provided protruding around the hole 9, and a rubber spring 10, a membrane switch 12, which will be described later,
6 wooden positioning protrusions 4 for positioning the support plate 13 are protruded at approximately constant intervals, and a large number of bosses 8 with screw holes slightly lower than the positioning protrusions 4 are provided on the frame 1 for fixing the support plate 13 with screws. protruding from various places on the back side of the

A rubber spring 10 is disposed on the lower side of the frame 1 to bias the keys upward, and the rubber spring 10 is integrally molded into a sheet shape of silicone rubber, for example, and is disposed at a position corresponding to each key. An inverted cup-shaped bulge ill is formed so as to be connected to the flat base portion 10a, and a switch operating portion 11a for pushing the membrane switch 12 is formed inside the center of the inverted cup-shaped bulge portion 11. The flat base portion 10a of the rubber spring 10 has a hole 5 that fits into the positioning protrusion 4 protruding from the back surface of the frame 1 and a hole 6 that loosely fits into the screw hole boss 8 at predetermined locations. to be drilled.

The membrane switch 12 is a known thin film switch in which a circuit pattern including electrodes is formed on the opposing surfaces of a pair of soft and elastically deformable insulating films such as polystyrene films, and a spacer is interposed. A hole 7 that is loosely fitted into a screw hole boss 8 that projects from the back of the frame 1, three oval holes 14 that fit into the front row positioning projections 4 that project from the frame 1, and three oval holes 14 that fit into the front row positioning projections 4 that project from the frame 1 Holes 15, which are loosely fitted into the positioning protrusions 4 of At this time, this expansion and contraction is prevented from being transmitted to the membrane switch, so that the membrane switch 12 is not stretched or wrinkled.

The support plate 13 is made of a rigid metal plate so as to support the membrane switch 12 from below.On the support plate 13, there are holes 16 for positioning the front row of the frame 1, oval holes 16 that fit with the mating protrusions 4, and holes for the rear row. A hole 19 that loosely fits into the positioning projection 4 of the frame 1, and a screw hole 20 for inserting a screw into the screw hole of the screw hole boss 8 of the frame 1 are formed. This screw hole 20 is formed to have a diameter smaller than the diameter of the threaded post 8, and is secured by tightening with the screw 21 while the top surface of the support plate 13 is securely in contact with the end face of the threaded post 8. be.

A key stem 18 of a key 17 is fitted into each guide tube 2 of the frame 1 so as to be able to move up and down. is energized by A check piece that engages with the frame 1 is provided at the lower end of the key stem 18 to limit the upper limit of the key's protrusion.

Each member of the keyboard having the above structure is assembled in the assembly process as follows.

First, the rubber spring 10 is placed on the upside down frame 1, and the rubber spring 10 inserts its inverted cup-shaped bulging portion 11 into the annular pressing portion 3 on the back side of the frame, and also inserts the rubber spring 10 into the flat base portion 10a. The holes 5 and 6 provided are fitted into the positioning protrusion 4 and the screw hole post 8 on the frame l side, respectively, and the membrane switch 12 is placed on the rubber spring lO (on the back side) and is drilled there. The oval hole 14 is fitted into the positioning protrusion 4 of the front row,
Hole 15. is loosely fitted to the positioning protrusion 4 in the rear row, and furthermore, the hole 7 is loosely fitted to the screw hole post 8. With this, the membrane switch 12 becomes a frame! and is accurately positioned with respect to the rubber spring 10 by the positioning protrusion 4. Further, the support plate 13 is placed on the membrane switch 12 (on the back side), the oval hole 16 of the support plate 13 is fitted into the positioning projection 4 of the front row, and the hole 19 is loosely fitted with the positioning projection 4 of the rear row. Then, insert the screw 21 from the screw hole 20 of the support plate 13, screw the screw 21 into the screw hole post 8 of the frame 1, and attach the support plate 13 to the frame 1.
Tighten and secure.

At this time, the lower end of the threaded post 8 is in direct contact with the upper surface of the support plate 13 without intervening the rubber spring 10 or membrane switch 12, and the support plate 13 is tightened with the screws 21. Rotational force is not transmitted to the membrane switch 12, and assembly can be performed without causing wrinkles or tension. Also, at this time,
Since the large number of annular pressing parts 3 on the back surface of the frame l press down on the flat base part 10a of the rubber spring 10, the membrane switch 12 is held between the upper surface of the support plate 13 and the lower surface of the flat base part 10a of the rubber spring. The membrane switch 12 is held in place, and the membrane switch 12 is accurately and reliably fixed to the rubber spring 10 and the key 17 on the frame without being displaced.

In the keyboard configured in this way, when the key 17 is pressed down, the key stem 18 pushes down the inverted cup-shaped bulge ll of the rubber spring IO, and the switch actuating part 11a formed inside it is moved to the membrane switch 1.
2, thereby pressing the membrane switch 1 onto the membrane switch 1.
The switching operation is performed by bending the upper film of No. 2 and bringing the upper and lower electrodes into contact with each other.

<Effects of the Invention> As explained above, according to the keyboard of the present invention, the membrane switch is sandwiched between the upper surface of the support plate and the lower surface of the base of the rubber spring. As there is no rotational force applied to the screws when fixing this membrane switch, there is no wrinkles or tension caused by it, and this eliminates chattering during switching operations and delays in key-in that would otherwise occur due to wrinkles or tension in the membrane switch. can be prevented

[Brief explanation of drawings]

The figures show an embodiment of the present invention, in which Fig. 1 is an exploded perspective view of the keyboard, Fig. 2 is a cross-sectional view of the keyboard in the lateral direction, Fig. 3 is an enlarged sectional view of the key switch section, and Fig. 4 is the back side of the frame. It is a diagram. DESCRIPTION OF SYMBOLS 1... Frame, 10... Rubber spring, 10a... Flat base part. DESCRIPTION OF SYMBOLS 11... Inverted cup-shaped swelling part, 12... Membrane switch, 13... Support plate. 17...key.

Claims (1)

[Scope of Claims] A flat frame, a key vertically movably supported by the frame, a support plate fixed to the frame, and a pair of insulating films placed on the support plate. A membrane switch having a circuit pattern including electrodes formed on opposing surfaces thereof and a spacer interposed therebetween, a flat base portion interposed between the membrane switch and the frame, and an inverted cup-shaped base portion at a position facing the key. What is claimed is: 1. A keyboard comprising: a rubber spring having a bulging portion and a switch operating portion; and wherein the membrane switch is held between an upper surface of the support plate and a lower surface of a base of the rubber spring.