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:
May. 31, 1994
Filed:
Feb. 19, 1992
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
An I-axis phase pulse is allowed to be detected at the sampling point of a chrominance signal with a digitally-implemented circuit. A chrominance signal (sampling frequency f.sub.1) is subsampled by a frequency f.sub.2 (f.sub.1 /N) and subsampling pulses generated in N subsampling pulse generators 10 for N phases, the adjacent ones of the pulses being shifted by one clock (1/f.sub.1) with respect to one another. The subsampled chrominance signal is input to an I-axis determining circuit 17. The I-axis determining circuit operates to detect a maximum value M.sub.1 of a color burst signal (sampling frequency f.sub.1) and the data M.sub.2 after one clock and compare both of the values with each other. Based on the compared result, a selecting signal S.sub.4 is detected for selecting an I-axis phase pulse at the sampling point of the chrominance signal. A selecting circuit 18 selects, as an I-axis phase pulse S.sub.5, a proper one of the N sampling pulse for N phases based on the selecting signal and applies the I-axis phase pulse S.sub.5 to an (N+1)th subsampling circuit 19. The subsampling circuit 19 can provide an I-axis detected output S.sub.3 at the sampling point of the chrominance signal.