| 摘要 |
PURPOSE:To eliminate a ghost signal automatically, by detecting, in view circuit, the polarity and amplitude of an in-phase and an orthogonal components of the waveform of the ghost signal. CONSTITUTION:The 1st synchronizing detection circuit 6, a carrier wave pickup circuit 7, a 90 deg. phase shift circuit 8, and the 2nd synchronizing detection circuit 9 are circuits synchronizingly detect a video intermediate frequency signal and demodulates the signal, and the in-phase component is obtained from the 1st synchronous detector 6 and the orthogonal component is obtained from the 2nd synchronous detector 9. Both the components are respectively added at an addition circuit 12 via amplitude adjusting circuits 10 and 11. This added output is similar to a ghost waveform and applied to an adder 1 via a variable delay circuit 3 and ghost is eliminated. On the other hand, a difference circuit 13, an integration circuit 14, and sampling circuits 15, 16 pick up residual ghost in a video signal from the adder 1, the aplitude and polarity of the in-phase and orthogonal components are respectively detected and applied to adjusting circuits 10, 11 as a control signal. |
