| 摘要 |
PROBLEM TO BE SOLVED: To clamp a disk by a minimum necessary clamping force when attaching/detaching a disk, and by a large clamping force when rotating the disk, since simultaneous achievement of the high-speed rotation of the disk and the easy unclamping of the disk is difficult when disk clamping performed by the magnetic attraction force of a permanent magnet acting between a chucking pulley and a turntable for holding the disk therebetween. SOLUTION: This device is provided with a first clamper 21 moved into a turntable 12 in a radial direction by a centrifugal force generated during disk rotation to clamp a disk 10 from its one surface, and a second clamper 22 for clamping the inner periphery of a disk center hole 10a, and the magnetic force of the permanent magnet 5 of the turntable 12 is weaker than conventionally. During a high-speed disk rotation, the disk is strongly clamped by a magnetic force and the clampers 21 and 22, and during unclamping, the clamping is released by weak power countering the clamping force corresponding to a weak magnetic force. Thus, both are simultaneously achieved.
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