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:
Apr. 15, 1986
Filed:
Dec. 06, 1983
Tomotaka Saito, Yokohama, JP;
Abstract
A sweep circuit of a key matrix, has an output circuit wherein a series circuit of a pair of transistors with a terminal interposed therebetween is inserted between a power supply and a reference potential, and a timing pulse for selectively turning on one of said pair of transistors is supplied to the gates of the pair of transistors so as to produce a key scanning signal; an input circuit wherein a transistor is inserted between a terminal connecting an output side of the key matrix and the reference potential, the key matrix being connected between the terminals of the output and input circuits; and a transistor which switches to insert a current limiting resistor between the reference potential and the transistor at the reference potential side in each of the input and output circuits in the non-read-in mode.