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. 16, 1976
Filed:
Sep. 23, 1974
Applicant:
Inventors:
Assignee:
Sony Corporation, Tokyo, JA;
Primary Examiner:
Int. Cl.
CPC ...
H04B / ;
U.S. Cl.
CPC ...
325364 ; 325 21 ; 325 64 ; 325397 ;
Abstract
Circuits for use with a receiver which notify the operator of a receiving station by means of an audio tone when an opposite station is calling or has ceased transmission. The transition of an opposite station from its transmitting to receiving state or vice versa is detected and a specific change-over sound based upon the detector output is introduced into the principal station's receiver audio amplifier circuits.