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:
Mar. 20, 1979
Filed:
Jan. 23, 1978
Kouichi Hasegawa, Tokyo, JP;
Nippon Electric Co., Ltd., Tokyo, JP;
Abstract
A multi-frequency signal receiver for use in tone signalling circuits is disclosed. The receiver includes a plurality of channel band pass filters having mutually independent pass bands, each of which receives the input signal. Threshold detectors are connected to the outputs of the channel bandpass filters as is a variable threshold circuit. The variable threshold circuit includes a peak hold circuit and an attenuator for generating a threshold value for the detectors. A rectifier and integrator circuit rectifies an output which is weighted compared with the output of the peak hold circuit to produce a timing signal. The timing signal is used to gate the output of the detectors.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile