Signal pickup device for reproducing an information signal recorded on a track of a rotary recording medium

A signal pickup device for use in an apparatus for reproducing an information signal recorded in a track on a horizontal surface of a grooveless rotary recording medium, said signal pickup device comprising:

• a reproducing stylus means for tracing the track on the rotary recording medium, thereby reproducing an information signal recorded in the track;
• means including a cantilever arm supported by damper means so as to be rotatable about substantially the proximal end and movable in an axial direction, and having said reproducing stylus at a free distal end thereof;
• means comprising a permanent magnet fixed to the proximal end of said cantilever arm and having magnetic poles on the opposite lateral faces thereof, said poles extending in the axial direction of said cantilever arm means, movement of said magnet causing said cantilever to move said reproducing stylus;
• a tracking control coil means secured to a support structure of said pickup device with a pair of winding surface portions extending in substantially a vertical direction to confront the poles of said permanent magnet;
• and
• means for generating a tracking control signal current in response to a tracking error, said signal current being supplied to said tracking control coil means,
• the tracking control signal current fed to said tracking coil means flowing through said pair of vertical winding surface portions in opposite directions with respect to each other, the electromagnetic field resulting from the energization of said coil causing said permanent magnet to rotate about a vertical axis for rotating said cantilever arm means, due to a mutual reaction between the electromagnetic field and the tracking control signal current, whereby the reproducing stylus is displaced so as to trace a track with the tracking error controlled.