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:
Sep. 19, 1978
Filed:
Jul. 15, 1977
Akira Mitarai, Yamatokoriyama, JP;
Sigekazu Fujiwara, Nara, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
An FS signal demodulator includes a zero-crossing detector which detects zero-crossings of frequency shift signals (FS), a pulse converter which generates a train of '0' and '1', '0' representative of a time slot from the first detected zero-crossing through a given period of time and '1' representative of a time slot from that period through the next succeeding zero-crossing, a memory means receiving the outputs of the pulse converter and thus containing the train of the pulses with the length corresponding to modulation rate, a counter means counting the number of '1's' or '0's' contained within the memory means in response to clock signals, and a determination circuit which effects frequency discrimination by comparing the counts of the counter means with a given limit.