| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical pickup device that reduces a signal offset caused by variation in spectral ratio of a diffraction grating while preventing an unnecessary luminous flux reflected by an unintended recording layer from entering a light receiving surface when recording and reproducing a multilayered optical disk, to obtain a stable tracking error signal, and to provide an optical disk device equipped with the optical pickup device. <P>SOLUTION: The optical pickup includes a laser light source, an objective lens for condensing luminous flux on an information recording surface of an optical disk, a diffraction grating for dividing the luminous flux reflected on the information recording surface into a plurality of regions, and a light detector having a plurality of light receiving surfaces for receiving the luminous flux divided into a plurality of regions by the diffraction grating. A plurality of grating regions are formed in the diffraction grating so that they are line-symmetric with respect to the center line in the direction corresponding to the track direction of the optical disk, or point-symmetric with respect to the center position. The grating pitches of the grating regions which are line-symmetric with respect to the center line or point-symmetric with respect to the center position are substantially the same. <P>COPYRIGHT: (C)2011,JPO&INPIT |
