Reduced height magnetic bias apparatus for a magnetooptical disk drive including a coil means having a central axis perpendicular to the rotating axis of a rotatable magnet

A magnetic biasing apparatus for use in a magnetooptical disk drive apparatus, said magnetic biasing apparatus being positioned adjacent to a magnetooptical disk generally opposite an optical head means, and

• said magnetic biasing apparatus comprising:
• a permanent magnet being rotatable about a rotating axis extended along the length of said permanent magnet, said permanent magnet having north and south poles extended in the direction perpendicular to the rotating axis;
• rotating means for rotating said permanent magnet, said rotating means consisting of only a single coil displaced adjacent to said permanent magnet so that said permanent magnet is positioned outside said coil, and said rotating means is oriented such that the central axis of said coil is perpendicular to a line connecting said north and south poles of said permanent magnet, the central axis of said coil is parallel to said magnetooptical disc;
• and
• drive means for controllably driving said rotating means to produce a magnetic field.