Ball-type imbalance compensator for axial motor of optical disc drive, has roll restricting unit for retaining magnetic ball after detachment from magnet

摘要

The compensator includes a magnet (16) within a main body (12). At least one magnetic ball (14) is arranged in side the main body, outside the magnet. The magnetic ball can be attracted to the outer circumference of the magnet. A roll restricting unit (18) is arranged around the magnetic ball for retaining the magnetic ball after the magnetic ball has detached itself from the magnet.