| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical pickup device with compact structure capable of interchanging and reproducing plural kinds of optical recording media. SOLUTION: An optical pickup device 10 is equipped with a first semiconductor laser 1, a second semiconductor laser 11, collimetor lenses 2, 22, polarized beam splitters 3, 33, quarter wavelength plates 4, 44, a lens 5, condensing lenses 6, 66, and optical detectors 7, 77. The lens 5 comprises three nonspherical surfaces 51, 52, 53, and an optical surface 54; a 635 nm wavelength laser beam emitted from the first semiconductor laser 1 is condensed and projected to a signal recording suraface 9a of an optical recording medium 9 with a 0.6 mm thickness substrate by a first objective lense composed of the nonspherical surface 52, the optical surface 54, and the nonspherical surface 51; a 780 nm wavelength laser beam emitted from the second semiconductor laser 11 is condensed and projected to a signal recording surface 90a of an optical recording medium 90 with a 1.2 mm thickness substrate by a second objective lens, composed of the nonspherical surface 53, the optical surface 54, and the nonspherical surface 51; then these signals are subjected to recording and/or reproducing on optical recording media with different thickness substrates. |
