| 摘要 |
<p>PURPOSE:To improve the performance and to attain costdown by using a single voltage controlled oscillator and a clock obtained derivatively thereby and bringing a signal into a component signal whose time base is compressed at once affer one A/D conversion. CONSTITUTION:A sampling clock when a composite video signal 1 is converted by an A/D converter 3 is supplied by a 4fsc oscillator 11(fsc is a 3.58MHz subcarrier frequency). Only a frequency band including 3.58MHz is passed through be a transversal filter 4, a color signal obtained by a 1H delay circuit 5 and an attenuator 6 and an output of an LPF 2 give a Y signal by a subtractor 7, and a luminance signal 25 is obtained from an LPF 22. A clock (a variable phase difference from a 4fsco Y/C separation clock) obtained from the signal 25 via a D-FF 17 is used to apply an R-Y signal 27 and a B-Y signal 28 to a time base compression circuit 18, then an output 26 of time axis compression color signal is obtained through a D/A converter 19 and an LPF 21 and an inexpensive device with simple constitution is obtained.</p> |
