Patent ID: 7602690

Claim:
An optical pickup that includes an aberration adjustment device for adjusting an aberration related to light emitted from a light source, and records or reproduces data in an optical information recording medium having a guiding groove by using the light adjusted by the aberration adjustment device, wherein the aberration adjustment device includes: an aberration generation element configured to generate a correction aberration on the light emitted from the light source; a control signal generator configured to extract a reproduction signal from light reflected from the optical information recording medium, and configured to extract a signal corresponding to a shape of the guiding groove from light reflected from the optical information recording medium, the signal corresponding to the shape of the guiding groove being separate from the reproduction signal and the signals being detected at predetermined addresses of the optical information recording medium; and wherein the aberration adjustment device is configured to adjust the correction aberration generated by the aberration generation element based on the reproduction signal and the signal corresponding to the shape of the guiding groove, to thereby adjust for astigmatism in the optical pickup.