Patent ID: 8111603
Filing Date: 2012-02-07
Classification: G11B

Abstract:
1. An optical disk apparatus which reproduces first and second optical disks, comprising: a laser to emit a laser beam having a predetermined wavelength; a first objective lens to focus the laser beam having the predetermined wavelength emitted from the laser on the first optical disk and having a first numerical aperture; a second objective lens to focus the laser beam having the predetermined wavelength emitted from the laser on the second optical disk and having a second numerical aperture; an optical disk discrimination circuit to discriminate a kind of the optical disk mounted; and a laser driver to supply a laser driving current on which a first high-frequency current having a first amplitude and a first frequency is superposed to the laser when the first optical disk is mounted and to supply a laser driving current on which a second high-frequency current having a second amplitude and a second frequency is superposed to the laser when the second optical disk is mounted, wherein the laser driver supplies a laser driving current on which no high-frequency current is superposed to the laser when the optical disk discrimination circuit discriminates the kind of the optical disk before the optical disk apparatus reproduces information on the optical disk, and supplies a laser driving current on which the first or second high-frequency current is superposed to the laser after the optical disk discrimination circuit discriminates the kind of the optical disk.