| 摘要 |
<p>A video signal is applied to a series circuit consisting of a multiplier stage (2) and a usual device (5) for the black level control. The device (5) is set by a control signal for black value adjustment, and a video signal is collected from the multiplier (2) output. The video signal is the product of the input video signal and a signal proportional to the control signal. The multiplier stage (2) has an input from an addition stage (11). The two inputs of the addition stage are derived from trim potentiometers.</p> |
