| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical information recording and reproducing head system that can be downsized, simplified and cost-reduced by performing excellent reading from / writing to an optical disk without the need for controlling an output of a semiconductor laser. <P>SOLUTION: The optical information recording and reproducing head system for leading a luminous flux emitted from a light source onto an optical disk by an objective lens to record/reproduce/erase optical information, includes an aberration correction optical system placed between the light source and the objective lens to correct spherical aberration caused on the optical disk by changing the divergence of light, and the aberration correction optical system has at least two lens groups: a first lens group placed at the side of the objective lens and a second lens group placed at the side of the light source, and the objective lens is placed so that the principal point of the objective lens is located in the vicinity of the focus of the first lens group at the side of the objective lens. <P>COPYRIGHT: (C)2004,JPO |
