Keyboard switch

• US 4,501,938 A
• Filed: 04/06/1983
• Issued: 02/26/1985
• Est. Priority Date: 04/09/1982
• Status: Expired due to Fees

• Current Assignee: ALPS Electric Company Limited (Alps Alpine Co., Ltd.)
• Original Assignee: ALPS Electric Company Limited (Alps Alpine Co., Ltd.)
• Inventors: Kawauchi, Masahiko
• Primary Examiner(s): Pellinen, A. D.
• Assistant Examiner(s): Ginsburg, Morris
• Application Number:
  US06/482,579
• Time in Patent Office: 692 Days
• Field of Search: 200/5 A, 200/159 B, 200/292
• US Class Current: 200/5.00A
• CPC Class Codes: H01H 13/702 with contacts carried by or formed from layers in a multilayer structure, e.g. membrane switches
• CPC Class Codes: H01H 2203/016 universal; modular
• CPC Class Codes: H01H 2203/02 Interspersed fingers

Abstract

A keyboard switch includes a lower-electrode insulating sheet provided with an electrode pattern formed by arranging lower electrodes at given distances, each of the lower electrodes being composed of a pair of electrodes having interfitted teeth; and an upper-electrode insulating sheet provided with an electrode pattern formed by arranging a plurality of lines of rectangular upper electrodes so that each of the rectangular upper electrodes crosses the corresponding pair of teeth of the electrodes of the lower electrodes at right angles.

Claims

1. A keyboard switch including an insulating sheet provided with a lower-electrode pattern formed by arranging lower electrodes at given distances, each of said lower electrodes being composed of a pair of electrode portions having interfitted teeth spaced from one another;

and a second insulating sheet provided with an upper-electrode pattern formed by a plurality of lines of upper electrodes each formed by bar-shaped elements spaced from one another with the bar-shaped elements of each line being offset from the bar-shaped elements of the adjacent lines so that said upper electrodes can cross adjacent teeth of said pair of electrode portions of said lower electrodes.

2. A keyboard switch as defined in claim 1, wherein the distance A between said pair of electrode portions, the distance B between the adjacent ones of said lower electrodes, and the length C of each of said upper electrodes are related to each other under a condition of B>

C>

A.

3. In a keyboard switch having a lower electrode formed by a plurality of electrode elements arranged in pairs so that each pair may comprise a respective switch when connected electrically together, an upper electrode lying over said lower electrode and having electrode patterns adapted to electrically interconnect respective pairs of electrode elements when pressed theretowards, and a pattern formed over said upper electrode for indicating portions thereof to be depressed for connecting the respective pairs of electrode elements electrically together, the improvement wherein said electrode patterns of said upper electrode are arranged in a plurality of lines and each consists of a bar-shaped element, the bar-shaped elements of each line thereof being offset from the bar-shaped elements of adjacent lines whereby a common design for the upper electrode can be used for a wide variety of patterns that could be formed over said upper electrode.