| 摘要 |
PURPOSE:To drive stably an objective lens extending over a long period of time by supporting pivotally a holder for holding the objective lens by an intermediate member so as to be slidable on a plane being orthogonal to an optical axis of the objective lens, and supporting this intermediate member so as to be variable in the optical axis direction of the objective lens. CONSTITUTION:When a current having amplitude and polarity corresponding to a size and a direction of a focusing error is made to flow to a focusing coil 9, a holder 2 and an intermediate member 4 are displaced as one body in the optical axis direction of an objective lens 1 by an electromagnetic action to a magnetic circuit having a permanent magnet 13, by which a focusing control of a light spot to a disk can be executed. Also, when a current having amplitude and polarity corresponding to a size and a direction of a tracking error is made to flow to a tracking coil 10, the holder 2 turns on a place being orthogonal to the optical axis of the objective lens 1 against the intermediate member 4 centering around a shaft 3 by an electromagnetic action to the magnetic circuit having the permanent magnet 13, by which a tracking control of the light spot to the disk can be executed.
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