| 摘要 |
PROBLEM TO BE SOLVED: To enable aberration compensations at the time of reading out information from plural kinds of recording medium whose thickness of optically transparent layers are different by moving operate a compensating element for compensating the spherical surface of an objective lens to be provided at an entrance pupil side with respect to the objective lens over the inside and the outside of an optical path with a linearly driving mechanism. SOLUTION: A linearly driving coil 12 is provided in a slide mechanism to generate a driving force in a linear direction by being combined with a magnetic flux to be generated from a linearly driving magnet and moves a corrected lens holder provided with a corrected lens 14. The corrected lens 14 is supported in a lens holder and is a lens compensating the aberration due to the kind of an optical recording medium 101 and is moved in the linear direction with the slide mechanism as necessary to be inserted into an optical path being directly under and objective lens 38. The lens holder is of the flate rectangular parallelepiped plate shape integrally formed in the slide mechanism part and is provided with the corrected lens 14 and the center of the principal plane. |
