| 摘要 |
<P>PROBLEM TO BE SOLVED: To make it possible to adjust with ease and high accuracy a relative position between a light spot of a luminous flux reflected from an optical disk and a photo-detector for receiving this light spot. <P>SOLUTION: The photo-detector 11 for receiving the luminous flux reflected from the optical disk D is provided with at least two position detecting segments 118, 119 for receiving ± primary diffracted light beams passing through a hologram element 10, and these position detecting segments 118, 119 have an area of almost the same diameter as the spot diameters of ± primary diffracted light beams, and perform position adjustment of the photo-detector 11 based on photo-detection outputs from these position detecting segments 118, 119. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
