DISK DRIVING DEVICE AND ROTARY DISK TYPE RECORDING/ REPRODUCING DEVICE

摘要

PROBLEM TO BE SOLVED: To prevent the plastic deformation or destruction of a rotary disk by reducing stress developed in a boundary between the disk part and the cylindrical part of the rotary disk when a large impact load is applied in a rotational center axial direction. SOLUTION: A rotor yoke 109 is fixed to a rotary disk 5 at a point closer to a rotational center axis 1 than the centroid position of an integrated article constituted of rotary magnet 110 and the rotor yoke 109 supporting the magnet 10 in a radial direction. By bringing the working point of a force from the integrated article constituted of the rotor yoke 109 and the rotary magnet 110 closer to the rotational center axis 1 when an impact load is applied, moment generated at the rotary disk 5 is reduced, stress developed in a boundary between the disk part 3 and the cylindrical part 4 of the rotary disk 5 is reduced, and thus the plastic deformation or destruction of the rotary disk 5 is prevented.