| 摘要 |
PURPOSE:To extract a color signal with high quality, by using a scanning line of adjacent field of a composite color television signal, separating the color signal and reducing a residual color signal to a luminance signal. CONSTITUTION:An NTSC signal inputted to a terminal 1 is inputted to a delay circuit 2 where the signal is delayed by 263H (where H is a horizontal scanning period), and a difference with the signal delayed by 263H is obtained at a subtraction circuit 3. Since the phase of a subcarrier is inverted for a present scanning line and the signal delayed by 263H, the signal having the amplitude double the chrominance carrier signal is obtained as an output of the circuit 3. This is multiplied by 1/2 at a multiplication circuit 4, a band taking the subcarrier frequency as a center is extracted at a BPF 5, then a desired chrominance carrier signal (signal C) is obtained at an output terminal 8. In subtracting this signal from the present signal (NTSC signal) at a subtraction circuit 6, a luminance signal (Y signal) is obtained at an output terminal 7. |
