| 摘要 |
PURPOSE:To prevent a reproduced video signal from dot interference and to improve S/N by subtracting and removing the secondary higher harmonic of an unnecessary low band-converted chrominance carrier included in a luminance signal by using a higher harmonic generated from a chrominance signal. CONSTITUTION:The output of a reproducing head 1 is supplied to a reproducing preamplifier 3 through a transformer 2. An FM signal is sampled by an HRF4 and applied to a subtrator 9 through an FM demodulator 6, an LPF7 and a de-emphasis circuit 8. On the other hand, a chrominance signal is sampled by an LPF5 and applied to an output circuit 10 through an ACC11, a frequency converting circuit 12 and BPF13. A part of the output of the LPF5 is inputted to a higher harmonic generating circuit 14, which generates the higher harmonic of a low band-converted chrominance signal fs and takes out only a double higher harmonic 2fs to subtract said higher harmonic 2fs by the subtractor 9 and remove the unnecessary higher harmonic of the luminance signal. The output circuit 10 mixes the luminance signal with the chrominance signal to output a reproduced video signal. |
