Abstract: In a video disc player, a stylus arm, carrying a track-following stylus at one end thereof, has its other end secured to an arm cage by a compliant member. The arm cage is translated along a path disposed radially of the disc record during playback. Pickup circuits are employed for sensing the variations in a signal representative capacitance formed between an electrode incorporated in the pickup stylus and conductive material disposed in the record to recover prerecorded information from a spiral track disposed on the record. A stylus position indicative capacitance, established between a first electrode secured to the stylus arm and coupled to the pickup circuits and a second electrode mounted to the carriage in the vicinity of the first electrode, is modulated at a given frequency rate. Circuitry is provided for sensing signals at a given frequency appearing at the output of the pickup circuits to generate a signal indicative of the position of the pickup stylus relative to the arm cage.

Abstract: A reproducing stylus traces a track of a recording medium, in which track an information signal is recorded as variations of geometrical shape, and reproduces as variations in capacitance the information signal thus recorded. The reproducing stylus comprises a reproducing stylus main structure having a tip part with a flat sliding contact face for slidingly contacting a plurality of track of the recording medium at a time, and an electrode secured to the reproducing stylus main structre at the tip part thereof and adapted to trace one track and reproduce the information signal as the variations in capacitance in accordance with the variations in geometrical shape. The electrode has over a specific distance over the tip part of the stylus main structure from the extreme tip thereof, a constant width in the width direction of the track which is less than the width of the track. The extreme tip of the electrode has a flat or linear tip end contacting the track.

Abstract: In a video disc player, a carriage is subject to translatory motion in correlation with radial motion of a playback stylus relative to a disc record. A stylus arm carrying the stylus at one end thereof has the other end pivotally secured to the carriage. A permanent magnet is mounted on the stylus arm near its free end. A pair of spaced coils having non-magnetic cores are disposed on the carriage such that the stylus arm-mounted magnet is interposed therebetween. The coils are selectively energized to change the radial location of the stylus relative to the record.

Abstract: The feeding device feeds a reproducing transducer in an apparatus for reproducing signals from a rotary recording medium having an information signal recording track formed thereon in a spiral path or concentric circular form and having reference signals recorded thereon interrelatedly with the information signal track. The reproducing transducer has a reproducing element for reproducing the information signal and the reference signals recorded on the rotary recording medium and tracking control mechanism for accomplishing tracking control so that the reproducing element traces the information signal track.