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

摘要

An optical disc device includes: a light source; a condensing system including a solid immersion lens for emitting light from the light source onto an optical disc; a gap control circuit for setting a distance between the solid immersion lens and the optical disc to a constant value; a CPU for adjusting a condensing position of emission light from the solid immersion lens with respect to an information recording/reproducing surface of the optical disc by moving a concave lens in a direction of an optical axis; and a focus control circuit for setting the condensing position on the information recording/reproducing surface, while following plane displacement of the information recording/reproducing surface, using a focus error signal. The CPU is operable to correct coma aberration in focus position adjustment by moving the concave lens in a direction perpendicularly intersecting with the optical axis.