SIGNAL PROCESSING CIRCUIT

摘要

PURPOSE:To make the change of rise and fall of a color signal sharp and to obtain a picture with its clear contour by controlling the gain of an amplifying circuit which amplifiers the color signal synchronously with the rise and fall of a low frequency liminance signal. CONSTITUTION:The quick rise of an edge pulse PC is synchronous with the leading edge of a low frequency luminance signal YL. Here the voltage level of a control signal DELTAV obtained by an amplifier A drops when a pulse of P1 is supplied. In such a case, a current I2' is suddenly reduced in adverse proportion to the sudden rise of the pulse P1. Therefore the voltage level of an output signal BOUT has a sudden rise although a signal B is applied with the color separation and detection, rises slowly. While a pulse P2 whose negative polarity of the PC falls quickly is supplied, and even the voltage level of the signal DELTAV rises, the current I2' rises sudden. Thus the signal BOUT also has a sudden drop despite a slow fall of the signal B.