Scanning head for video disc with spiral track - has V=shaped electromechanical transducer controlling force with which pick=up rests on disc

摘要

The scanning head has a support piece (6) and a pick-up (7) attached separately to the pick-up arm. The pick-up can be displaced perpendicular and/or parallel to the surface of the video disc (1) so that its position relative to the support piece can be changed. The pick-ups positional movement is controlled by a volt. applied to electromechanical transducers (9, 10). The two transducers consist of plates joined to form a V-shape whose pointed ridge is attached to the pick-up. The V-shaped transducer is enclosed in a casing filled with a damping liq. (11). The force with which the pick-up rests on the video disc is controlled by d.c. volts. applied to the transducers.