| 摘要 |
<p>A chrominance signal processing apparatus used for such as the color television signal recording and reproducing apparatus (VTR) to record and reproduce a color television signal, comprises means (2,3,26,17,24) for converting a carrier chrominance signal (fsc) to a low-band signal (fc) for recording, and, for reproduction, means (27,16,13) for reconverting the converted low-band signal (fc) to the carrier chrominance signal (fsc) of the original color subcarrier frequency, to thereby record and reproduce the chrominance signal. Means (40, 41, 42, 43) for detecting the burst in the carrier chrominance signal (fsc) necessary for the level adjustment of the chrominance signal or for the control of the conversion frequency or for discrimination of black and white signal under a state of the low-band converted chrominance signal during recording and reproduction, the level detection, phase detection, and synchronous detection in low frequency are made possible. Further, the level detection, phase detection, and synchronous detection are carried out after once demodulating the low-band converted chrominance signal into two color difference signals in the base band to thereby use a part of circuit in common and improve performance. Furthermore, by performing digital sampling demodulation for demodulating the low-band inverted burst into the base band by means of an AID converter and digital circuits, integration of digital LSis, combined used of detection circuits, detection circuits and a part of frequency conversion circuits, realization of any non-linear characteristics and reduction of external parts such as analog filters become possible of the chrominance signal processing apparatus. Accordingly, a small and inexpensive chrominance signal processing apparatus of low consumption power is realized.</p> |
