| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical pickup device which can correct a spherical aberration due to error in thickness of a covering layer of an optical recording medium having a thin cover layer, such as a Blu-ray disk and so on, and be miniaturized. <P>SOLUTION: The optical pickup device 42 includes a first lens 43 and a second lens 44, the focal lengths of which are variable and on which light emitted from a light source is incident. The optical pickup device 42 can correct a spherical aberration by changing the beam diameter of light by changing the focal lengths of the first and second lens 43 and 44 by means of a focal length changing means 45, a light detection means 15 and a control means 46. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
