The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 02, 1982
Filed:
Mar. 25, 1980
Ryoichi Sado, Saitama, JP;
Koichi Nei, Tokyo, JP;
Shin-Etsu Polymer Co., Ltd., Tokyo, JP;
Abstract
The invention provides a novel key-board switching unit used, for example, in pocketable electronic calculators for producing binary-coded signals corresponding to contacting of movable contact points on the bottom surface of a keyboard covering pad and fixed contact points on the printed circuit board on which the covering pad is mounted when pushed with a finger tip or a pushing means. The printed circuit board in the inventive switching unit has a so fine and complicated circuit pattern that, in the prior art, one or more of jumping circuits crossing over a printed base pattern are indispensable resulting in much increased production costs while, in the inventive switching unit, the circuit pattern on the circuit board per se may be incomplete by the lack of such jumping circuits and, instead, the covering pad is provided with conductive connections corresponding to the lacking jumping circuits on the circuit board to form necessary jumping circuits when the covering pad is mounted on the circuit board.