| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical pickup device capable of obtaining a stable servo signal. <P>SOLUTION: First to fourth separating sections 71 to 74 for tracking are formed in first to fourth divided regions 71a to 74a of a light separating means 45 respectively so as to deviate from the diffracted light passing region where the diffracted light reflected and diffracted by a recording layer 41b on the side deeper than the recording layer 41a on the light source side viewed from the light source 4 when the light beam is condensed to the recording layer 41a on the light source side. In first to fourth detection sections 91 to 94 for tracking, the light diffracted and separated by the first to fourth separating sections 71 to 74 for tracking is detected. A tracking error signal is obtained by a phase difference between a change in the addition value of light intensity detected by the first and fourth detection sections 91 and 94 for tracking and a change in the addition value of light intensity detected by the second and third detection sections 92 and 93 for tracking. <P>COPYRIGHT: (C)2008,JPO&INPIT |
