| 摘要 |
An optical pickup apparatus, including a light source to emit light, an objective lens to form a light spot on an optical recording medium by focusing the light emitted from the light source, an optical division unit, disposed between the light source and the objective lens, to divide the light emitted from the light source into a main beam and two subbeams to form one main spot and two subspots on the optical recording medium, the optical division unit having a first area and a second area surrounding the first area, a detector to detect the amount of light of the main beam and the amount of light of the respective subbeams reflected from the optical recording medium, a beam splitter disposed between the light source and the objective lens to allow the light reflected from the optical recording medium to be directed to the detector, signal generating circuits to generate a tracking error signal (TES), a focusing error signal (FES), and a spherical aberration signal (SAS), respectively, in response to the output of the detector, and a spherical aberration compensation unit, disposed between the objective lens and the beam splitter, to compensate for spherical aberration using the SAS generated by the signal generating circuits.
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