Patent ID: 7898922
Filing Date: 2011-03-01
Classification: G11B

Abstract:
1. An optical pickup apparatus comprising: a first objective lens having a low numerical aperture (NA) suitable for a low-density recording medium; a second objective lens having a high NA suitable for a high-density recording medium; a first light source to generate a short-wavelength optical signal to use the first and second objective lenses; a plurality of first photo-detectors to receive the optical signal, which is generated from the first light source, the optical signal being focused on a recording medium by the first and second objective lenses and reflected from the recording medium; a beam splitter to perform a division of the optical signal generated from the first light source, to direct some parts of the divided optical signal to the first objective lens, and to direct the other parts of the divided optical signal to the second objective lens; a plurality of collimating lenses disposed in optical paths between the beam splitter and the first and second objective lenses to correct spherical aberrations of the objective lenses; a holder to hold the plurality of collimating lenses so that the holder can simultaneously drive the plurality of collimating lenses; and a drive connected to the holder to move the holder.