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. 04, 1986
Filed:
Mar. 26, 1984
Kazutoshi Hirohashi, Yokohama, JP;
Yukinobu Ishigaki, Tokyo, JP;
Victor Company of Japan, Limited, Yokohama, JP;
Abstract
In a noise reduction circuit for reception of stereophonic FM signals in which the demodulated signal is chopped at twice the pilot frequency for separation between left- and right-channel signals, the demodulated signal is sampled by a first sample-and-hold circuit in response to the output of the noise detector to store that portion of the signal which appeared immediately prior to the occurrence of an impulse noise. The demodulated signal is also sampled by a second sample-and-hold circuit at a frequency twice the pilot frequency to eliminate a noise which might arise due to the chopping of the demodulated signal. A signal is derived from the outputs of the first and second sample-and-hold circuits that indicates the slope ratio of the demodulated signal at the moment that occurred immediately prior to the impulse noise. The slope ratio signal is applied to a linear integrator to generate a compensating voltage which is summed with the signal sampled by the first sample-and-hold circuit at the level which occurred immediately prior to the occurrence of the impulse noise.