Disk drive unit having a turntable with a projection to assure proper

Abstract

A disk drive unit has a turntable in which a central pin projecting from the center of a disk mounting surface, a drive pin projecting from an eccentric position spaced away from the position of the central pin, and a magnet for making the disk attract to the disk mounting surface are provided. The central pin and the drive pin are fitted in respective insertion holes provided in the core of the disk, while the core is fixed to the disk mounting surface due to attractive force of the magnet, so that the disk may be rotated by the turntable. Further, an arc-like projection having a predetermined height a little smaller than that of the disk mounting surface is so provided on the turntable as to extend outside the disk mounting surface and that along the outer edge of the turntable. The arc-like projection and the drive pin are disposed on opposite sides of the central pin. Thus, the core of the disk is prevented from being mounted on the disk mounting surface in a slanted state when information is to be recorded on reproduced from the disk.