Patent ID: 6532118
Filing Date: 2003-03-11
Classification: G11B

Abstract:
An objective lens actuating device comprising:a holder holding an objective lens; a supporting part movably supporting said holder at least in a focusing direction; a focusing coil being cylindrically wound in an axis parallel with an optical axis of said objective lens and fixed on said holder; an inner yoke located inside said focusing coil and having a flat surface extending in said focusing direction and a direction perpendicularly crossing said focusing direction; an outer yoke arranged so as to partially sandwich said focusing coil and face said inner yoke; a connecting member connecting said inner yoke and said outer yoke; a magnetic field generating part generating a magnetic field with said focusing coil in a gap formed by said inner yoke and said outer yoke; and an auxiliary magnetic field generating part generating an opposite magnetic field in respect to said magnetic field which is generated in said gap towards said focusing coil, at both ends of said inner yoke vertical to said focusing direction.