JPH0342583Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Technical Field> The present invention relates to a key input device such as a calculator.

<Prior Art> A conventional key input device such as a calculator is shown in FIGS. 5 and 6. In both figures, 15 is a key top, 10 is a decorative panel, 16 is a key rubber spring, 9 is a cabinet, and 7 is a printed circuit board.

FIG. 5 shows a key input device constructed by inserting a key top 15 into a cabinet 9, and then inserting a key rubber spring 16 and the cabinet 9.

FIG. 6 shows a key input device constructed by inserting a key top 15 into a key rubber spring 16 and then inserting the key top 15 into a cabinet 9.

However, in such a conventional key input device, a collar is provided at the lower end of the key top 15 to prevent it from slipping out, and the key top 15 is inserted from below the cabinet 9, so there is a limit to how narrow the space between the key tops 15 can be. be. Also, before assembling the set, attach the key top 15 to the key rubber spring 16.
In order to insert the key top 15 into a key, the orientation of the key top 15 may be incorrect, or an error may occur in which the key top 15 with a key symbol other than the specified key symbol is inserted in a predetermined position.

<Purpose of the invention> The present invention has been made in view of these conventional drawbacks, and it is possible to make the distance between the key tops very narrow, and also to allow the key top to be inserted after the set is assembled. It is an object of the present invention to provide a key input device that improves key operability and allows accurate and quick key top insertion work.

<Example> The present invention will be explained in detail below based on the figures.

1 and 2 show an embodiment of the present invention, with FIG. 1 being a sectional view of the key input device before the key top is inserted, and FIG. 2 being a sectional view of the key input device after the key top is inserted. In both figures, reference numeral 1 denotes a key top formed in a plate shape, and a protrusion 2 provided with an undercut portion 3 for preventing falling off is provided on the lower surface. Reference numeral 4 denotes a key rubber spring, which is provided with a movable contact 5 and a key top insertion hole 6 into which a protrusion 2 of the key top 1 is inserted, as shown. Reference numeral 7 denotes a printed circuit board, and a fixed contact 8 is provided at a position facing the movable contact 5 of the key rubber spring 4.

Since the key input device of the present invention is constructed as described above, the key rubber spring 4 integrated with the printed circuit board 7 is inserted into the through hole provided in the upper cabinet 9 with the decorative panel 10 of the device, and then the upper cabinet is inserted. The projection 2 of the key top 1 can be press-fitted into the hole 6 of the key rubber spring 4 from outside 9.

According to this configuration, the key tops 1 have a T-shaped cross section and can be expanded in the horizontal direction, so that the key tops can be spaced very close to each other. Therefore, key operability can be improved.

Furthermore, since the key top 1 can be inserted while directly viewing the key symbol from above the upper cabinet 9 after assembly, erroneous insertion of the key top 1 can be prevented and ease of assembly is greatly improved.

Further, since the insertion protrusion 2 is completely fixed by the elasticity of the key rubber spring 4 and the undercut portion 3 for preventing falling off, it is possible to prevent the key top 1 from falling off.

3 and 4 show other embodiments of the present invention,
FIG. 3 is a sectional view of the key input device before the key top is inserted, and FIG. 4 is a sectional view of the key input device after the key top is inserted. In both figures, reference numeral 11 provided in the key rubber spring 4 is a hole for inserting a key top, and reference numeral 12 is a hole 1 for inserting the key top.
This is a stepped portion provided within 1. Further, 13 is a key sheet, 14 is a movable contact provided on the key sheet 13, and the other configurations are the same as those in FIGS. 1 and 2.

This embodiment is constructed so that the undercut part 3 for preventing falling off is fitted onto the step part 12, and with this structure, the effect of preventing the key top 1 from falling off can be further enhanced.

<Effects of the Invention> As described above, the key input device of the present invention has a key top formed into a plate shape, and the key top is provided with a support for insertion into an elastic board, and a drop-off prevention means is provided on the support. By providing a hole in the substrate into which the support column can be inserted, and inserting the support column into the hole, the operability of the key can be greatly improved. In addition, incorrect insertion of the key top can be prevented and ease of assembly can be improved. Furthermore, the key top will not fall off the key rubber spring.

[Brief explanation of the drawing]

1 and 2 are cross-sectional views of a key input device according to the present invention, and FIGS. 3 and 4 are cross-sectional views of other embodiments,
5 and 6 are cross-sectional views of a conventional key input device. 1: Key top, 2: Protrusion on the bottom of the key top,
3: Undercut part to prevent falling off, 4: Key rubber spring, 6: Key top insertion hole, 7: Printed circuit board, 11: Penetrated key top insertion hole,
12: Step part.

Claims (1)

[Claims for Utility Model Registration] A key input device in which an elastic substrate having a movable key contact is installed on a substrate having a fixed key contact, and a separately formed key top is attached from the elastic substrate, the key input device comprising the steps of: What is claimed is: 1. A key input device, characterized in that the key top is formed into a shape, a projection is provided on the lower surface of the key top, and a hole for fitting the projection of the key top is provided in the elastic substrate.