| 摘要 |
PURPOSE:To derivate a synchronized video signal and to use it generally even when the device to use a different clock in the recording and reproduction is adopted by synchronizing at the time of starting respective component signals at the reproducing side and generating a sampling clock. CONSTITUTION:A VCO30 gives an output having a writing clock frequency N2fH to a phase shifter 35 and a frequency dividing circuit 31, the circuit 31 makes an input into 1/N2 and gives it to a phase comparing circuit 32, compared with a horizontal synchronizing signal H of a frequency fH formed from a reproducing chrominance signal, and in accordance with the phase difference, the VCO30 is controlled. At a shifter 35, a saw-tooch wave signal SAW is generated and given to a comparing circuit 37 based upon the rise of the input signal, and a comparing output with direct current voltage V1 or V2 given through a switch 38 is supplied to an A/D converter and a memory control circuit as a chrominance signal writing clock.
|
