US Patent 7921435 Optical disk drive

An optical disk drive according to the present invention includes: an optical pickup 6 including a light source 23 that radiates a light beam 21 to irradiate an optical disk 100, at least one objective lens 22 for converging the beam 21, and an actuator that can move the lens 22 perpendicularly to the disk 100; a transport stage 11 for displacing the pickup 6 in a disk radial direction; a rim detecting section 30 for sensing if the irradiated position of the beam 21 has passed an outer edge of the disk 100 while the pickup 6 is being displaced from an inner area of the disk toward the outer edge thereof to conduct a seek operation; and a control section 40 for getting the lens 22 retracted away from the disk 100 by the actuator and getting the pickup 6 displaced toward the inner area of the disk by the transport stage 11 if the irradiated position of the light beam 21 has been sensed to have passed the outer edge of the disk 100.