OPTICAL PICKUP DEVICE AND OPTICAL DISK DEVICE

摘要

PROBLEM TO BE SOLVED: To provide an optical pickup device, when an optical disk having a plurality of recording layers is recorded/reproduced, capable of suppressing variation of a tracking error signal by stray light and attaining a reduction in size.SOLUTION: An optical pickup device includes: a semiconductor laser 50 for emitting a laser beam having a wavelength of approximately 405 nm; an objective lens 2 having a numerical aperture of approximately 0.85 which irradiates an optical disk with the light beam emitted from the semiconductor laser; and a photodetector 10 having a light receiving part for receiving the light beam reflected by the optical disk. An optical magnification from the optical disk to the photodetector 10 is made in the range of approximately 10 to 15 times.