| 摘要 |
Provided is an optical pickup apparatus which has a function for correcting spherical aberration caused by a thickness error of a transparent substrate (15) and which is sufficiently compact, wherein a collimator lens (13) used in the apparatus is composed of two lens groups (11,12), an interval between the two lens groups is changeable, and therefore spherical aberration caused by the thickness error of the transparent substrate is corrected. |
