| 摘要 |
PURPOSE:To eliminate the need of a resistance value adjusting operation by applying the output of an integrating circuit connected to a chrominance component signal transmitting signal line to a switching terminal side used at the time of inserting no chrominance signal of an analog switch. CONSTITUTION:The integrating circuit 5 consisting of a resistor R0 and a capacitor C0 is connected between the signal line 3 and an earth and the output point of this integrating circuit 5, namely, the connecting middle point of the resistor R0 and the capacitor C0 is connected to the switching terminal L of the analog switch 4. During a blanking period, since the chrominance component signal C itself is generally constituted only of a DC component, the DC component is outputted as it is as an integrating signal. Even when the chrominance component is present during such a blanking period, this chrominance component passes through the integrating circuit 5 and integrated, thereby, it is outputted as the DC component of substantially the same level. In such a way, the integrating circuit 5 is only added to the switching terminal L side, thereby, the chrominance component can be effectively removed during the blanking period.
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