| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a low cost optical pickup device capable of generating a stable servo signal and when recording and reproducing an optical disk having a plurality of information recording layers and being downsized, and to provide an optical disk drive having the same. <P>SOLUTION: A diffraction element has first, second, and third division regions; the third division region includes the center of the diffraction element; the first division region is on a straight line extending in a direction substantially parallel to a track of an optical disk passing through an approximate center of the diffraction element; the second division region is on a straight line extending in a direction substantially perpendicular to the track of the optical disk passing through the approximate center of the diffraction element; and the diffraction element is divided at least into four parts. Zero-order diffraction light of the first division region, the second division region, and the third division region is detected at least by four-division light receiving parts, and at least two light receiving parts detecting light beams diffracted in the first division region with a first or higher diffraction order are arranged in a direction substantially perpendicular to the track of the optical disk. <P>COPYRIGHT: (C)2013,JPO&INPIT |
