| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical recording/reproducing system capable of precisely detecting spherical aberration suitable to the 3-dimensional optical recording/reproducing of a recording layer thicker than a conventional optical disk and employing not only an astigmatism method using a cylindrical lens in a focal point sensing method used for conventional optical pickup but also the other focus error detecting method. <P>SOLUTION: A pattern 15a reflectivity different from a reference pattern 13 is formed on a recording medium. The diameter of a light spot S is estimated from the pattern 15a having the same reflected light amount as measured light reflected on the reference pattern 13. Then, the focusing point is detected and the spherical aberration is corrected by controlling the aberration. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
