| 摘要 |
PURPOSE:To reduce the surface deflection of a disk due to a deformation of the disk, the external vibration, etc., by turning the disk with two viscoelastic rollers which hold the outer circumference part of the disk between them. CONSTITUTION:A disk 5 is put on a turntable 4, and the 1st viscoelastic roller 10 is turned by a motor 12 with no up-down movement. The downward force is applied to the 2nd viscoelastic roller 11 attached to a cover body 2 and by means of a spring, etc. When the cover 2 is closed, the disk 5 is held by a disk clamper 6 and the 2nd roller 11 and turned with a control given so that the surface deflection of the disk is minimum on a straight line connecting the table 4 and the 1st roller 10. An optical pickup 7 which shifts right and left on the lower surface of the disk 5 works at the area where the surface deflection is minimum. In such a way, the surface deflection is reduced by holding the outer circumference part of the disk with rollers. |
