Patent ID: 6785209
Filing Date: 2004-08-31
Classification: G11B

Abstract:
An optical pickup used with an optical disk, comprising:a light source emitting a light beam; light splitting means for splitting the light beam into at least two light beams including a first beam and a second beam; optical path changing means for changing a traveling path of the first and second beams reflected from the optical disk; an objective lens focusing the first and second beams to form a main light spot and an auxiliary light spot, respectively, on the optical disk; a photodetector having first and second light receiving portions receiving the first and second beams reflected from the optical disk and passed through the optical path changing means, respectively, and performing photoelectric conversion on the received first and second beams to produce electrical signals; and a signal processor correcting aberration caused by tilting of the optical disk, using the electrical signals, wherein: the light splitting means comprises a polarization beam splitter causing a predetermined amount of coma aberration only to the second beam, not to the first beam, such that the first beam has a polarization component without aberration, and the second beam has the other polarization component including coma aberration; and the optical path changing means comprises: a beam splitter changing the traveling path of the first and second beams by transmitting or reflecting the first and second beams each in a predetermined ratio based on an amount of light, and a polarization beam splitter disposed along an optical path between the beam splitter and the photodetector, transmitting or reflecting the first and second beams reflected from the optical disk and passed through the beam splitter according to polarization; wherein the first and second light receiving portions of the photodetector are arranged separated from each other to receive the first and second beams passed through the polarization beam splitter, respectively.