| 摘要 |
PURPOSE:To improve the S/N and at the same time to suppress the color variance, by giving the synchronizing wave detection to a carrier signal by means of a signal which contains no phase modulation component. CONSTITUTION:An image pickup tube 34 delivers a direct signal obtained by mixing a luminance signal Y with color signals R, G and B, a carrier signal which is decided by the pitch of the thin streak of a color separating stripe filter 11, and a high band signal respectively. An LPF38 extracts three primary color signals SL, and BPFs 39 and 40 extract the high band components respectively. The output signals of BPFs 39 and 40 are supplied to a multiplier 41, and a third higher harmonic signal which receives no phase modulation through a BPF is extracted. This higher harmonic signal is supplied to a frequency divider 44 via an amplifier 43 to be converted into a carrier. Furthermore one side of the higher harmonic signal is supplied to a multiplier 45, and the other side is supplied to a 90 deg. phase shifter 46 respectively. The signals R, G and B are produced from a matrix circuit 50 and via LPFs 48 and 49. |
