Patent ID: 8165002
Filing Date: 2012-04-24
Classification: G02B,G11B

Abstract:
1. An optical pickup apparatus comprising: a laser diode; an objective lens made of synthetic resin material having a refractive index greater than or equal to 1.61 with respect to laser light having a wavelength of 405 nm, the objective lens arranged in an optical path of laser light between the laser diode and an optical disc so that the laser light from the laser diode is focused onto a signal recording layer through a protection layer of the optical disc; and a collimating lens interposed in an optical path of the laser light between the laser diode and the objective lens, the collimating lens configured to be operated so as to correct spherical aberration caused by moisture-absorption characteristics of the objective lens, the spherical aberration being corrected by moving the collimating lens in an optical axis direction of the laser light to a position selected from a position at which a jitter value contained in a reproduced signal is minimized and a position at which an RF signal level is maximized.