JPS647342A - Device for driving objective lens - Google Patents

Abstract

PURPOSE:To reduce the access time by moving a movable part along the axial direction of a supporting shaft at focus control and driving the moving part around the supporting shaft at tracking control so as to prevent an objective lens from being tilted at the focus control. CONSTITUTION:In forming the image of a laser beam onto a disk face for the write/read to an optical disk, the objective lens driving device is moved by a linear motor 66 to apply coarse access based on a slot on the disk and a scale 70. When out of focus of a beam spot or the positional deviation of a track due to a warp of the optical disk or its deflection is detected, the objective lens driving mechanism makes access accurately to the objective lens to compensate the deviation. The out of focus is corrected by energizing a focus coil 24 to move the movable part 12 with a coil 24 wound thereto in the axial direction through the action of the magnetic field of a magnet 45. Moreover, the positional deviation of the track is corrected by energizing a track coil 26 so as to drive the movable part 12 around a shaft 28 against the elastic force of regulating members 54, 56.