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:
Jan. 01, 2002
Filed:
Apr. 14, 1999
Takeshi Misaku, Osaka, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A circuit for automatically discriminating audio intermediate frequencies of a received television signal that has a simple, compact and inexpensive circuit structure and can operate stably. The circuit comprises a high pass filter circuit for eliminating a synchronizing signal from an output of a video intermediate frequency detector; a synchronizing signal separation circuit for separating a synchronizing signal from the output of the video intermediate frequency detector; a waveform shaping circuit for shaping a waveform of an output signal of the high pass filter circuit; a counter for counting predetermined clock pulses; a counter controlling circuit, which, triggered by the separated synchronizing signal, (i) causes the counter to count the number of the clock pulses that are contained during a period of time that is defined based on the output of the waveform shaping circuit, and (ii) causes the counter to output a counted value; and a discrimination signal output circuit for discriminating a range, within which the counted value falls, from a plurality of ranges, and outputting a discrimination signal according to the result of the discrimination. The plurality of ranges are partitioned corresponding to audio intermediate frequencies.