| 摘要 |
PURPOSE:To quicken the response time, by connecting each one end of the 1st and the 2nd resistors connected to each emitter of transistors (TRs) to each base of which a vidio signal and a black frame signal are inputted respectively and connecting an output terminal to the connecting point of the resistors. CONSTITUTION:A video signal of negative polarity is applied to a terminal 20, and a black frame inserting signal is applied from a terminal 29. A reference potential Vref is equal to a pedestal level of input signal of negative polarity. Trs 21, 25, resistors 23, 24 and a constant current source 22 constitute an attenuator circuit and Trs 27, 28, 30, 31 resistors 32, 33, 34 and a constant current source 26 constitute a switching circuit. The black frame inserting signal is set to a low level when being inserted and to high level when being not inserted. |
