Patent ID: 7948835

Claim:
An optical disc device comprising: a light source; a condensing system including a solid immersion lens for emitting light from the light source onto an optical disc; a gap controller for performing gap control of setting a distance between the solid immersion lens and the optical disc to a constant value; a focus position adjuster for performing focus position adjustment of adjusting a condensing position of light to be emitted from the solid immersion lens with respect to an information recording/reproducing surface of the optical disc; a focus error signal generator for generating a focus error signal based on light from the information recording/reproducing surface; a focus controller for performing focus control of setting the condensing position on the information recording/reproducing surface, while following plane displacement of the information recording/reproducing surface, using the focus error signal; and a coma aberration corrector for performing coma aberration correction of correcting coma aberration in the focus position adjustment by moving at least one of lenses to be used in the focus position adjustment in a direction perpendicularly intersecting with an optical axis.