| 摘要 |
PROBLEM TO BE SOLVED: To obtain a YC separation circuit which can suitably suppress or reduce cross color or dot disturbance in a weak electric field. SOLUTION: A color TV signal received in a weak electric field is passed through a high-pass filter to directly extract a signal for C signal extraction, the extracted signal is amplified up to a predetermined level, A/D converted, and then inputted to 2-line comb filter to thereby obtain a C signal. Meanwhile, the color TV signal received in the weak electric field is A/D converted to a digital composite signal and then applied to a subtractor. In this process, the square value of a color burst amplitude is detected respectively from the signal for C signal extraction and the composite signal, a conversion ratio is calculated to convert the C signal extracting signal to the amplitude level of the C signal in the composite signal, and the conversion ratio is multiplied by the generated C signal and applied to the subtractor to obtain a Y signal. COPYRIGHT: (C)2004,JPO
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