| 摘要 |
An optical pickup device for recording/reproducing an optical disc having at least two data storing layers on one side thereof generates a first and second laser beams of same polarization (S-polarized beams) from a first and second laser beam sources. The laser beams are incident on a prism of a cubic type in which a dielectric coating layer for selectively total reflecting or total transmitting depending to a polarizing state of an incident beam is formed at a diagonal surface (45 DEG ) of the prism. Instead of the prism of the cubic type, only a dielectric coating plate may be positioned at the diagonal surface of the prism. The first S-polarized beams is total reflected by the dielectric coating layer for reading out information recorded on a first layer of the optical disc. The second S-polarized beams is total reflected toward a polarization converting plate, and thus the beam is converted into P-polarized light to return to the prism. The P-polarized beams is total transmitted through the dielectric coating layer for reading out information recorded on a second layer of the optical disc.
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