| 摘要 |
PURPOSE:To improve the picture quality by giving priority to the improving capacity of a threshold phenomenon or the reproducing capacity of a color signal according to the level of the carrier color signal component. CONSTITUTION:The carrier signal component is extracted from a composite video signal delivered from a frequency discriminator 14 through a BPF22, and this extraction output is smoothed via a wave detector 23 and an LPF24. The gain of a variable attenuator 21 is reduced with the smoothing output level is low and the input level of an IF signal is reduced to an ILO13. While the gain of the attenuator 21 is increased to increase the input level of the IF signal when the smoothing output level is high. Therefore the priority is given to the improving capacity of a threshold phenomenon in the case of a reduced carrier color signal component with which the reproducing capacity of the color signal is not so important. While the priority is given to the reproducing capacity of the color signal with a large amount of carrier color signal component with which said reproducing capacity is important on a screen. |
