| 摘要 |
PURPOSE:To correct the deterioration in the vertical resolution due to a rewritten signal by generating a 2nd luminance signal of opposite polarity while its phase is advanced by 1H through a separate signal path from the substantial path, adding the signal to a substantial (1st) luminance signal, extracting the rewritten signal only at the output, using it as a correction signal so as to take a difference from the 1st luminance signal. CONSTITUTION:A video signal A is separated into color difference signals U1, V1 and a luminance signal Y1 and converted into analog signals Y5, U5, V5 by D/A converters 4-6. Since the signal Y1 is delayed by one line at a digital signal demodulation circuit 2 in the signals Y1 and inverse of Y2, the phase of the signal, inverse of Y2 is advanced by 1H. Moreover, a transistor in switching operation by a blanking pulse B generated in a blanking pulse generating circuit 23 extracts only a rewritten signal having a double speed to obtain a correct signal D2. Then the signal D2 is inputted to one input of a differential amplifier 24, the signal Y5 is given to the other input, then they are subject to differentiation, thus the luminance signal Y5 is a signal whose change is suppressed by the luminance change transient state.
|
