| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical pickup in which change of power of a laser beam emitted through an objective lens can be suppressed even when a collimator lens is moved to correct spherical aberration during reproduction of a multi-layer disk. <P>SOLUTION: An optical pickup 1 is arranged at a reference position so that optical distance D1 between a collimator lens 13 and an objective lens 11a for BD becomes focal distance Fcol 1 or less of the collimator lens 13 during incidence of a laser beam with a short wavelength, and optical distance D2 between the collimator lens 13 and an objective lens 11b for CD/DVD becomes focal distance Fcol 2 or more of the collimator lens 13 during incidence of the laser beam with a long wavelength. <P>COPYRIGHT: (C)2009,JPO&INPIT |
