| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical pickup device capable of reducing costs and manufacturing steps by constituting an objective lens of an infinite system objective lens and driving an optical unit including a light source-photodetector in an optical axis direction to correct a spherical aberration caused by the cover layer thickness error of an optical disk, and an optical disk device. <P>SOLUTION: A control unit 21 corrects the spherical aberration of a laser beam 50 by instructing a unit driving part 25 to displace an irradiation detection unit 3 in an optical axis direction M1. For example, the irradiation detection unit 3 is brought close to a wavelength plate 14 to shorten an optical path between an LD 11 and the infinite system objective lens 16. Thus, the spherical aberration of the laser beam 50 is roughly corrected with respect to the cover layer thickness of a second layer 120. This spherical aberration is fine-adjusted by displacing the irradiation detection unit 3 in the optical axis direction M1 to find the length of the optical path where a RF signal detected by a PDIC 18 is maximum. Lastly, the control unit 21 starts reading of the second layer 120. <P>COPYRIGHT: (C)2010,JPO&INPIT |
