Patent ID: 6505001
Filing Date: 2003-01-07
Classification: G11B

Abstract:
A rotor structure for a spindle motor of an optical disc apparatus, comprising:a turntable, formed to support an optical disk; a chucking magnet positioned in a center of an upper side of the turntable, that is insert molded from a plastic material including magnetic particles; a shaft, molded with the turntable; a rotor yoke molded with the turntable and made from a soft magnetic metallic material, forming a cup-like shape which has a circular opening on a center of an underside of the rotor yoke and a portion turned up to form a back yoke in the center of the turntable; and a rotor magnet on an inner surface of the rotor yoke such that the shaft passes through the circular opening on the center of the underside of the rotor yoke, a part of the turntable is extended as far as an inner side of the rotor yoke, beyond an internal margin of a circular opening in the rotor yoke, to make contact with the rotor yoke, and the shaft, the chucking magnet and the rotor yoke form a single integrated piece.