| 摘要 |
PURPOSE:To enable to eliminate a comb line filter and improve vertical resolution of chrominance signals by making BPF output a control signal of a control amplifier. CONSTITUTION:Modulated color signals 15 of BPF output become successively color difference signals 18 in a detector 16 and switched at every 1H period by switching signals 21 and the color difference signals are synchronized successively. The BPF 33 passes frequency of 1/2 horizontal scanning period of synchronized color difference signals G/2-B23, compares with reference potential 35 by a comparator 34 and makes it a control signal of a control AMP 32. Thus, loop gain is set control output of 1HDL 19 by the control AMP 32 to reduce fH/2 component of synchronized color difference signals, that is, to reduce difference of amplitude at every 1H.
|
