| 摘要 |
PURPOSE:To reduce an output error of a control voltage generating circuit and to stabilize the operation, by differentiating an output signal of a delay element and that of a comparison circuit, respectively. CONSTITUTION:Delay elements 11-16 are connected in cascade and input or output video signals are supplied to them. The output of the elements is applied to gain control circuits 21-26 and the gain is controlled variably. An adder 104 sums the output of the gain control circuits and a subtractor 105 subtracts the inputted video signal from the output of the adder 104. A comparator 103 compares the output of a reference signal generator 102 with the output of the subtractor 105. The 1st differentiating devices 810a-810f differentiate the output of the delay elements and the 2nd differentiating device 820 differentiates the output of the comparator 103. The corresponding output out of those of the 1st differentiating devices and the output of the 2nd differentiating device are applied to control voltage generators 101a, 101f, from which a gain control signal of the gain control circuits is generated. |
