Patent ID: 6212019
Filing Date: 2001-04-03
Classification: G11B

Abstract:
An objective lens driving system in an optical pick-up comprising:a lens holder which has a shaft hole and holds an objective lens;a fixed member which has a journal inserted into said shaft hole;a magnet and a driving coil which are arranged opposite each other so as to generate a magnetic force for driving said lens holder along said journal; anda magnetic piece which is arranged opposite said magnet to hold said lens holder at a neutral position using said magnetic force generated between said magnet and said driving coil while said driving coil is not excited, said magnetic piece being magnetized until it is saturated by emf from the magnetic field generated by said magnet;each of said magnet and magnetic piece having an associated magnetic flux density and wherein the magnetic flux density generated by said magnet is larger than the saturation flux density around said magnetic piece.