Patent ID: 8023386
Filing Date: 2011-09-20
Classification: G11B

Abstract:
1. An optical pickup apparatus for applying through an objective lens a beam from a semiconductor laser to an optical disk having two recording layers, introducing reflected light from the optical disk to a focus-error-signal-detecting light receiving device and a track-error-signal-detecting light receiving device through the objective lens and a beam splitting part, and reproducing information from the optical disk, wherein: when the beam from the semiconductor laser is focused on one of the two recording layers through the objective lens, the beam splitting part splits the beam in such a manner as to apply the reflected light from the recording layer of the two recording layers, on which the beam is focused, to the focus-error-signal-detecting light receiving device and the track-error-signal-detecting light receiving device, and also, to prevent the reflected light from the recording layer of the two recording layers, on which the beam is not focused, from being applied to at least one of the focus-error-signal-detecting light receiving device and the track-error-signal-detecting light receiving device, and the light splitting part has its area separated by a separating line which is larger than a diameter of an area to which the reflected light from the recording layer of the two recording layers on which the beam is not focused is applied to the light beam splitting part, such that the separating line is located outside of the area to which the reflected light from the recording layer of the two recording layers on which the beam is not focused is applied to the light beam splitting part.