| 摘要 |
An input video processor utilizes the characteristics of a modulator having two differential pairs of transistors with respective gain control terminals, in combination with a switch. The processor performs four distinct functions utilizing the same basic modulator; it provides blanking the video signal from the preamplifier to provide a clean pulse for clamping at a later stage; it clamps the output during black level firmly to ground potential to allow subsequent blanking; it allows the manipulation of the master gain of the three channels in a color television while independently adjusting the gain of the channels, while further maintaining absolute tracking between channels; and it provides an independent gain control input for a white shading control voltage input to perform white shading corrections.
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