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. 03, 1987
Filed:
Oct. 03, 1985
Applicant:
Inventor:
Toshihito Ichikawa, Saitama, JP;
Assignee:
Pioneer Electronic Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04H / ;
U.S. Cl.
CPC ...
381 15 ; 329112 ; 329124 ; 329137 ;
Abstract
An AM stereo demodulator with which the transition from the stereo receiving mode to the monaural receiving mode upon a reduction in the field strength of the received signal is made gradual so as to eliminate an abrupt change in the sound quality. For stereo demodulation, a pair of reference signals are generated which are .pi./2 different in phase for stereo reception. As the field strength of the received signal approaches the level where a phase-locked loop in the demodulator would become unlocked from the carrier of the received signal, the phase difference between the two reference signals is gradually reduced to .pi./4.