| 摘要 |
PURPOSE:To eliminate buzz sound by applying a differentiation value of a video signal in opposite phase to a sound signal input side while taking a notice that an unnecessary sound component corresponds to a rate of change of the amplitude of the video signal (differentiation value of the video signal). CONSTITUTION:A sound multiplex signal is fed to a sound signal transmission system 5 through resistors R2, R3 and a coupling capacitor C2, and a composite video signal from an input terminal 1 is fed to the sound signal transmission system 5 through a capacitor C1, the resistor R3 and the capacitor C2. The said video signal is differentiated by the capacitor C1 and a combined resistor R comprising resistors R1-R4. Signals from a video signal modulator 3 and a sound signal modulator 4 are synthesized by an adder circuit 6 so as to eliminate buzz sound specific to a sound multiplex receiver generated in synchronizing with the horizontal synchronizing signal and the result is outputted from an output terminal 7. |
