External magnetic field inverting apparatus for magneto-optical disc apparatus
AssigneeSony Corporation
InventorsTakashi Naito, Susumu Tosaka
Life of this patent
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Abstract
The present invention relates to an external magnetic field inverting apparatus for magneto-optical disc apparatus in which a permanent magnet (15) is used as external magnetic field generating means and a winding (25) is located so as to surround the permanent magnet (15), and the permanent magnet (15) can be half-rotated in a desired direction by a rotation force generated by a repulsive force by an external magnetic field Hm generated by this permanent magnet (15) and a magnetic field Hc resulting from supplying a current to the winding (25), whereby the apparatus of the invention can be reduced in cost, increased in reliability and miniaturized in size.
Claims7
An external magnetic field inverting apparatus for magneto-optical disc apparatus comprising a rotatable permanent magnet located a predetermined distance from a magneto-optical disc surface in opposing relation thereto and for generating an external magnetic field passing through said disc surface perpendicularly and a winding means located so as to surround said permanent magnet, and further means for supplying current to said winding means to create a second magnetic field different from the magnetic field of said permanent magnet, permanent magnet is half-rotated by a rotation force generated on the basis of a force occurring between both of said magnetic fields and applied to said permanent magnet whereby to invert the direction of the external magnetic field generated by said permanent magnet.
Dependencies are inferred from the claim text.