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. 19, 1996
Filed:
Oct. 21, 1994
Takahisa Hatano, Sapporo, JP;
Yoshihisa Nishigori, Itami, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A chrominance signal can be separated from a composite color television signal without misdetection in correlation detection even when the chrominance signal level is small by calculating vertical correlation values, comparing them with the threshold value corresponding to the chrominance signal level and judging if there is correlation or not. A chrominance signal separating apparatus includes a cascade connection of delay devices, where each delay device delays an input signal by 1H period. Comb filters separate a luminance signal and a chrominance signal from the composite color television signal by inputting two signals from the input and the output of each delay device which have a 1H period time difference. The output of one of the delay devices is regarded as a reference signal. A correlation detecting circuit calculates correlation values between the reference signal and a signal at the vertical vicinity of the reference signal on the screen. A level detecting circuit detects the level of the composite color television signal. Comparators compare the output of the correlation detecting circuit and the output of the level detecting circuit. A mixing circuit mixes the outputs of the comb filters based on the output of the comparators.