OPTICAL DISK DEVICE, METHOD FOR ACTIVATING OPTICAL DISK DEVICE, AND CONTROL CIRCUIT

摘要

PROBLEM TO BE SOLVED: To provide an optical disk device capable of suppressing coma aberration, while controlling a distance between a solid immersion lens and an optical disk to be constant.

SOLUTION: The optical disk device includes: a light source 120; a condensing system including the solid immersion lens 102; a gap control circuit 134 for controlling the distance between the solid immersion lens 102 and the optical disk 101 to be constant; a CPU 200 for adjusting the condensing position of emission light from the solid immersion lens 102 with respect to the information recording/reproducing surface 101b of the optical disk 101 by moving a concave lens 110 in the direction of an optical axis; and a focus control circuit 133 for holding the condensing position on the information recording/reproducing surface 101b, while following plane displacement of the information recording/reproducing surface 101b, using a focus error signal 128. The CPU 200 corrects coma aberration caused when adjusting focus position by moving the concave lens 110 in a direction LV perpendicularly intersecting the optical disk axis LA.

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