| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical pickup device having a laser diode for radiating three laser beams having different wavelengths and one object lense, which reads out signals recorded on optical disks having different standards.SOLUTION: An optical pickup device which reads out signals with an object lens 7 having a first numerical aperture, a second numerical aperture smaller than the first numerical aperture, and a third numerical aperture smaller than the second numerical aperture includes a collimator lens 5 which allows incident laser beams to be converted into parallel beams and a numerical aperture setting component 10 for setting the numerical aperture of the object lens irradiated with the laser beams. The numerical number set by the numerical aperture setting component 10 is smaller than the first numerical aperture. |
