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:
Nov. 21, 1989
Filed:
Jan. 19, 1989
Yoshinobu Takamura, Tokyo, JP;
Norimichi Katsumura, Yamanashi, JP;
Nebuhiko Osawa, Yamanashi, JP;
Kazuo Watanabe, Yamanashi, JP;
Pioneer Electronic Corporation, Tokyo, JP;
Pioneer Video Corporation, Yamanashi, JP;
Abstract
A demodulation clock generator circuit employed in a modulation system such as a bi-phase mark system is improved by including a frequency detector to speed up the initial processing of a data signal to be demodulated. The frequency detector generates a frequency detection signal which corresponds to a signal from an oscillator and a signal from a synchronization signal portion of the signal to be demodulated. The frequency detector includes a memory portion clocked by the oscillator for storing the states of the signal to be demodulated and a signal generating portion for supplying the frequency detection signal when information stored in the memory portion is the same as a synchronizing portion of the signal to be demodulated and has a frequency of less than a predetermined value.