| 摘要 |
<p>PURPOSE:To reproduce a picture of high quality by removing a noise, generated due to sampling of a composite color television signal at a frequency less twice its band fc, making use of correlation between fields. CONSTITUTION:A composite color television signal of frequency band fc inputted to terminal 1 is sampled at sampling frequency fs (fc<fs<2fc) by A/D converter circuit 2 and then inputted to field memory 4, so that a signal will be outputted which lags the input signal by 262H. The received signal and output signal of field memory 4 are alternated with code ''0'' at a rate of 2fs by change-over circuits 5 and 6 and inputted to LPF 7 and BPF 8 and 9. Higher harmonic components included in output signals of BPF 8 and 9 due to sampling are canceled by addition circuit 10 and a desired composite color television signal is obtained from terminal 13 via D/A converter circuit 12.</p> |
