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:
Sep. 20, 1983
Filed:
Jun. 16, 1981
Mitsuru Kudo, Katsuta, JP;
Isao Nakagawa, Katsuta, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A chrominance signal reproducing apparatus is proposed, in which an oscillation frequency of a first voltage-controlled oscillator is controlled by each of the error control voltages produced from APC and AFC circuits and the signal having the frequency component of the 1/4 output frequency of the first VCO and the output frequency signal of a second VCO are added to produce a sum frequency, which is used to frequency-convert a low-frequency converted carrier chrominance signal to a carrier chrominance signal before low-frequency conversion. The AFC circuit operates only when the frequency F'.sub.sc of the carrier chrominance signal before the low-frequency conversion is deviated 1/8 f.sub.H (f.sub.H : horizontal synchronizing frequency) or above with respect to the carrier chrominance frequency f.sub.sc, so as to apply the control voltage to the first VCO thereby to drive the deviation within the range of .+-.1/8 f.sub.H. When the f'.sub.sc is in the range of f.sub.sc -1/8f.sub.H <f'.sub.sc <f.sub.sc +1/8f.sub.H, the APC circuit controls the first VCO so that f'.sub.sc = f.sub.sc.