PURPOSE: To realize a high-speed access, by separating a recording or erasing magnetic field applying part from an optical head, and applying an even magnetic field to a magnetic thin film in the radius direction of a rotary disk from the magnetic field applying part.
CONSTITUTION: A permanent magnet 4 and an optical head 3 are set at the opposite sides each other centering on a magnetic thin film 2 of a photomagnetic disk 1. The magnet 4 is rotatable as shown by the arrow A so that it can reverse a magnetic field to the film 2 at both a recording time and an erasing time. An effective magnetic field always acts on an irradiated part of the light beam in both recording and erasing times respectively. When the head 3 crosses each track and a desired track is addressed, the magnet 4 is fixed and still. This ensures a high-speed access.
MUTOU AKIRA
ORUKAWA MASAHIRO
| JPS5740761A | 1982-03-06 | |||
| JPS57176505A | 1982-10-29 |