| 摘要 |
PURPOSE:To prevent deterioration of pulse signals by eliminating the front edge gradient of the pulse signals when the luminance control voltage is under a certain level, thus making sharp characteristics. CONSTITUTION:When rectangular pulse signals are added to an input terminal S01, they become integral waveform with the gradient accordant to the values of the resistance R1 and capacitor C1. If its size is changed by adding contrast control voltage to a terminal Sc1 and the impedance of a transistor Q1 is changed, thus changing the sum of the parallel resistance of resistances R2 and R3, the capacitor C1 damps. As a result, the contrast control is made pos sible. When a transistor Q2 becomes low luminance control voltage and is cut off, the high resistance R4 is included in seriew with the capacitor C1 and the integral action is not made and the pulse signal becomes rectangular. Therefore, the pulse signal deterioration does not occur.
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