| 摘要 |
PURPOSE:To reduce noise by comparing the maximum level of plural color difference signals with plural reference voltages, generating control signals corresponding to plural color difference signals and setting up plural color difference signals, then making each color difference independent. CONSTITUTION:A level detection means is constituted of clamp circuits 21a and 21b, limiter amplifiers 22a and 22b and full-wave shaping circuits 25a and 25b. The level detection means detects levels of plural arriving color difference signals, and the maximum level is selected among the detected signals by a selection circuit 26. comparators 27a and 27b have plural reference voltages corresponding to plural difference signals, compare plural reference voltages with the selected level detection signal, and generate control signals in correspondence to plural color difference signals. These control signals are supplied to analog switches 24a and 24b, which execute the amplitude suppression of corresponding color difference signals in accordance with plural control signals. |
