| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical pickup device that can record and/or reproduce information appropriately to three types of different optical disks and can be miniaturized, and to provided a drive device in an optical disk, an objective lens system used for the drive device, and a wavelength selection element. <P>SOLUTION: In the wavelength selection element for limiting an opening corresponding to the NA of a CD used for the optical pickup device compatible with a high-density optical disk, a DVD, and a CD, a phase structure for correcting spherical aberration caused by the difference in a protective layer thickness is formed at a first region including an optical axis, and a light-shielding structure for limiting the opening corresponding to the NA of the CD is formed outside the first region, thus recording and/or reproducing information appropriately to different types of optical disks. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
