| 摘要 |
PURPOSE:To attain ease of color demodulation by keeping a prescribed phase with a head data phase of write/read to a field memory with a continuous wave signal and keeping the continuity of a carrier signal phase locked a burst in a video signal after conversion. CONSTITUTION:A video signal Sv obtained from a video detecting circuit 4 is converted into a digital signal at an A/D converter 5 and fed to memories 16a and 16b at each approximate 1V via a switch circuit 16c and the write is conducted. The video signal written at the approximate 1V just before the memories 16a and 16b is read consecutively twice with a period of nearly 1/2 and this is obtained via a switch circuit 16d. The write/read to/from the memories 16a, 16b is controlled by a memory control circuit 17 so that the head data phase of the write/read to the memories 16a, 16b has a prescribed phase with a continuous wave signal locked a color burst signal Ssc (frequency fsc) extracted from the video signal Sv. |
