| 摘要 |
In a video signal processing system including a clamp for clamping the video signal to a reference level during periodic image blanking intervals of the video signal, and a kinescope for reproducing an image in response to the clamped video signal, apparatus for automatically limiting excessive beam currents drawn by the kinescope. A derived control signal representative of the magnitude of excessive beam currents is applied to the video signal processing path prior to the clamp. The control signal is inhibited during the blanking intervals, and serves to offset the D.C. level of the video signal in the black direction during image trace intervals to reduce the current conduction of the kinescope. |
