VIDEO DISC APPARATUS FOR CLEARING FOREIGN MATTER FROM THE SIGNAL PICKUP STYLUS DURING PLAYBACK

摘要

Accmulated foreign material on the signal pickup stylus of a video disc player tends to degrade the quality of the recovered information signal. The recovered information signal is detected and the nominal ampitude of the recovered signal is compared against a reference amplitude. The occurrence of a decrease in recovered signal amplitude below the level of the reference cause a comparator to generate a control or trigger pulse. The control pulse activates a pulse generator to produce a predetermined pulse sequence which is applied to a stylus deflection transducer to move the sylus fore and aft radially across the disc and thereby dislodge the foreign material from the picku stylus.