Optical pickup apparatus and optical disk drive apparatus
AssigneeRicoh Company, Ltd.
InventorsMasahiko Nakayama, Hiroshi Akiyama
Life of this patent
Estimating the term…
Abstract
An optical pickup apparatus for reproducing information from an optical disk, includes: a semiconductor laser applying a beam to an optical disk having two recording layers through an objective lens; and a light receiving device to which light reflected from the optical disk is directed through the objective lens and a beam splitting device, wherein: the beam splitting device has two first light receiving areas for detecting a push-pull signal and a second light receiving area for detecting a focus error signal, and a configuration is provided such that the center of the optical axis of the reflected light in the beam splitting device is made to lie within the second light receiving area for detecting the focus error signal.
Claims6
-14. (canceled)
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.
Dependencies are inferred from the claim text.