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:
Apr. 06, 1993
Filed:
Jan. 30, 1992
Masashi Itoh, Yokohama, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
Disclosed is a pilot signal cancelling system employed in an FM stereo receiver which does not cause deterioration of the S-N ratio. The system includes an input terminal for inputting a composite signal; a level detector for verifying the level of a pilot signal; a low pass filter for smoothing an output of the level detector; a cancelling wave generating circuit fo producing a pilot cancelling signal in response to an output of the low pass filter; a lamp trigger circuit for inputting the output of the low pass filter and outputting a lamp trigger signal; a lamp drive circuit for inputting the lamp trigger signal; a first computing circuit, connected to the level detector, for differentiating between the pilot signal in the composite signal and the pilot cancelling signal produced in the cancelling wave generating circuit; a second computing circuit, connected to an output terminal, for differentiating between the composite signal and the pilot cancelling signal; the output terminal for outputting the result of second computing circuit; and a switching circuit for switching on and off the connection of the pilot cancelling signal to the second computing circuit, by synchronizing the switching with the lamp trigger signal.