VIDEO SIGNAL PROCESSING CIRCUIT

摘要

A video signal processing circuit includes an amplifier with a circuit connected to it to emphasize the amplification of some frequencies relative to others. A non-linear circuit is also connected to the amplifier and comprises a capacitor connected in series with non-linear elements that change the amplification of positive and negative overshoots of the signal relative to the middle amplitude range. The result is non-linear modification of emphasis and can be used to preemphasize video signals before using them to modulate the frequency of a carrier and, in the playback section to deemphasize the signals to minimize FM noise. Use of the capacitor prevents direct current from flowing and thus affecting the threshold levels of the non-linear elements. Component values can be selected to effect temperature compensation.