| 摘要 |
<p>An optical pickup device capable of recording/reproducing information signals on/from first and second optical disks with different recording capacities, comprising an objective lens for condensing first and second light beams with different wavelengths onto the signal recording layer of a first or second optical disk with different substrate thicknesses, a beam splitter having the same transmittance to the first and second light beams and separating the first light beam from the second light beam respectively emitted from a first or second light source and received via the first or second light beam objective lens, and a hologram element disposed between the objective lens and the beam splitter, restricting the aperture of one of the first and second light beams and correcting spherical aberration caused by the difference between thicknesses of the substrates of the first and second optical disks, whereby enabling a shared use of optical components such as an objective lens and a beam splitter.</p> |
