US 4,570,039 AGranted

Keyswitch structure

AssigneeCasio Computer Co., Ltd.

InventorsHiroshi Osawa, Isao Kurashima, Yoshio Kawai

Life of this patent

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Abstract

In a keyswitch structure, a number of recesses are formed in a lower case, and a projection with a flat top surface is formed inside each of the recesses. The recesses communicate with each other by means of grooves formed on the lower case, and fixed contacts are provided on the projections. A pattern is formed on the under surface of a flexible substrate put on the lower case so that movable contacts, included in the pattern, face the fixed contacts. An elastic sheet with a number of buttons is put on the flexible substrate, and the flexible substrate and the elastic sheet are fixedly held between an upper case and the lower case. When any of the buttons of the elastic sheet is pushed, the elastic sheet and the flexible substrate are elastically deformed to bring the movable contacts into contact with the fixed contacts.

Claims10

Dependent claims

A keyswitch structure comprising:

an elastic sheet member having a plurality of operation portions adapted to be pushed by an operator and being capable of elastic deformation responsive to pushing;
a flexible circuit board adjacent to said elastic sheet member, said flexible circuit board having first conductive wiring patterns and first and second movable contacts which are opposite to said elastic sheet member and which are close to each of said operation portions, said flexible circuit board being pushable by said elastic sheet member to be depressed together with said first and second movable contacts thereof when said elastic sheet member is pushed;
a lower case carrying said elastic sheet member and flexible circuit board with said flexible circuit board interposed between said elastic sheet member and said lower case, said lower case having recesses which are respectively opposite to the operation portions of said elastic sheet member;
dot-like fixed contacts each formed on surfaces of said recesses which face said movable contacts and electrically connecting said first and second movable contacts of said flexible circuit board when said operation portions of said elastic sheet member are pushed to depress said flexible circuit board;
and
fixing means for firmly fixing together said elastic sheet member, flexible circuit board, and lower case.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application: 06/633,135Filed 23 Jul 1984
Priority: JP 58-13970730 Jul 1983
Granted: 11 Feb 1986
Term ends: Not estimatedThe source records don’t support an estimate.

Classification27 codes

H01H 13/785
Characterised by the contacts or the contact sites: characterised by the material of the contacts, e.g. conductive polymers
H01H 13/702
Having a plurality of operating members associated with different sets of contacts, e.g. keyboard: with contacts carried by or formed from layers…
H05K 3/061
The conductive material being removed chemically or electrolytically, e.g. by photo-etch process: etching masks
H01H 13/703
With contacts carried by or formed from layers in a multilayer structure, e.g. membrane switches: characterised by spacers between contact…