| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical pickup capable of properly setting a light branching state and a numerical aperture, and an optical disk playback device. <P>SOLUTION: The optical pickup is provided with a polarizing direction switching element for switching the polarizing direction of a laser beam between first and second directions to emit a light, a diffraction adjusting element for adjusting the diffracted state of the laser beam according to the first or second polarizing direction, and a numerical aperture adjusting element for adjusting a numerical aperture according to the first or second polarizing direction. The polarizing direction is switched between the first and second directions by the polarizing direction switching element, thereby adjusting the diffracted state (light branching state) by the diffraction adjusting element and adjusting the numerical aperture by the numerical aperture adjusting element. Thus, the playback conditions of the optical disk are properly set. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
