| 摘要 |
<P>PROBLEM TO BE SOLVED: To symmetrize a correctable range of aberration with respect to the reference thickness of an optical disk, even if a light source with a wavelength different from a reference wavelength is used. <P>SOLUTION: The optical pickup device is equipped with a semiconductor laser 11 that emits a laser beam with a wavelength of 450 mm or below, a single objective lens 16 with an NA 0.7 or less that converges the light beam from the semiconductor laser 11 to emit it to the signal recording face of an optical disk 100, and an aberration correcting mechanism 14 that controls parallelism of the laser beam entering the objective lens 16 to correct spherical aberration. The objective lens 16 is shaped so that the aberration correcting range in which the spherical aberration corrected by the correcting mechanism 14 becomes a prescribed value or below is symmetrized with respect to the reference thickness of the optical disk 100. <P>COPYRIGHT: (C)2003,JPO |
