| 摘要 |
An apparatus for driving an optical system has an objective lens for converging a light beam for recording or reproducing information to a recording medium composed of a vertically magnetized thin film having magnetooptic characteristics, and a driving device for electromagnetically moving the objective lens in the direction of an optical axis thereof or in a direction perpendicular to the optical axis. The driving device has at least two magnetic circuits composed of yokes and permanent magnets and has coils passing through magnetic clearances of the magnetic circuits. The magnetic circuits are approximately arranged symmetrically with respect to the optical axis of the objective lens. Magnetizing directions of the permanent magnets constituting the magnetic circuits are asymmetrically set with respect to the optical axis of the objective lens.
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