| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical pickup system by which spherical aberration and coma aberration are detected precisely. <P>SOLUTION: The system is provided with a split and photodetection means for splitting light returned from an optical recording medium into a plurality of partial beams and photodetecting them, and a detection means for detecting aberration from a photodetection signal corresponding to the photodetected partial beams. A mode of splitting the return light into the partial beams is a mode of splitting the return light in its cross section into three in a tangential direction 400 corresponding to the direction of an information record line on the optical recording medium, and splitting the partial beams at the center of them into four in a radial direction 401. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
