Coma aberration correcting apparatus and coma aberration correcting method

Coma aberration correcting method of the present invention is a recording and reproducing apparatus pickup coma correction in the method of recording or reproducing data on the optical disc by the pickup, irradiating a light beam to an optical disc including a plurality of recording layers comprising a first coma aberration correcting step of correcting the coma aberration of the optical system itself including the objective lens, and a second coma aberration correcting step of correcting the coma aberration due to the relative inclination of the optical disk and the optical system, the.