| 摘要 |
PURPOSE:To reduce the beat disturbance due to crosstalk by using a dynamic emphasizing circuit for line sequential chrominance signal which has the nonlinear amplitude characteristics and shows the larger emphasis to a small amplitude part of an input signal. CONSTITUTION:The line sequential chrominance signals of two color difference signals R-Y and B-Y are supplied from an input terminal 11. For these chrominance signals, a large emphasis is applied to a small amplitude part by a dynamic emphasizing circuit 12 having the nonlinear amplitude characteristics. A pre- emphasizing circuit 13 applies a larger emphasis to the high band component of an input signal. The input chrominance signal is changed to its original state through de-emphasizing circuits 25 and 26 having opposite characteristics to those of the circuits 12 and 13. When a part of the adjacent track is also reproduced, the angle modulated line sequential signal has an fH (horizontal scan frequency)/2 offset. Therefore the beat due to the crosstalk of a demodulation mode is also set at the fH/2. Thus the beat disturbance due to the crosstalk is reduced with interleaving. |
