Patent ID: 6155134
Filing Date: 2000-12-05
Classification: F16F,Y10T

Abstract:
A rotation control device, comprising:a rotation unit rotated by driving means; andat least one balancer member mounted on a portion of said rotation unit and adapted for being moved in an area spaced a distance less than a pre-set distance from the center of rotation of said rotation unit;said balancer member being moved relative to the rotation unit, upon rotation of said rotation unit, so that the synthesized center of gravity of said balancer member and said rotation unit will coincide with said center of rotationwherein said driving means is a spindle motor comprising:a spindle shaft; a cylindrical rotor; a bearing attached to a chassis which rotatably supports said spindle shaft; a coil located around the outer periphery of said bearing; and a magnet mounted on the inner surface of said cylindrical rotor, andsaid rotation unit includes a disc-shaped recording medium.