| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical pickup which is excellent in transmittance and light resistance for the short wavelength laser beam of approximately 400 nm used for recording/reproducing of high density optical disks, and correct the spherical aberration due to humidity changes, and provide an optical information recording and reproducing device having the optical pickup. <P>SOLUTION: The optical pickup detects humidity using a polymer film humidity sensor HUM. When humidity change is detected, the radiation angle of the light flux incident on the objective lens is changed by using a single axis actuator AC 1 to move the collimator lens CL by an appropriate distance in the optical axial direction, thereby correcting the spherical aberration caused by the humidity change. The radiation angle of the light flux incident on the objective lens is changed by using a single axis actuator AC 1 to move the collimator lens CL by an appropriate distance in the optical axial direction, thereby correcting not only the spherical aberration caused by the humidity change but also the spherical aberration caused by the thickness variations of the protection plate to the information recording surfaces in the BDs having a number of information recording planes in the thickness direction. <P>COPYRIGHT: (C)2010,JPO&INPIT |
