Optical Disk Device and Optical Disk Discriminating Method
AssigneeHitachi, Ltd.
InventorsTakeyoshi Kataoka, Motoyuki Suzuki
Life of this patent
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Abstract
An optical disk discriminating method and an optical disk device which can detect reflected rays for making discrimination among kinds of optical disks with high accuracies. By switching a plurality of lasers and moving a spherical aberration corrector while moving an objective lens to cause it to approach or keep away from an optical disk, rays reflected light from the optical disk can be detected with high accuracies. Discrimination among the kinds of a plurality of optical disks can be made on the basis of signals generated from the detected reflected rays. This ensures that the kind of an optical disk can be determined through one operation of sweeping.
Claims1
An optical disk device comprising:
- an optical pickup including a plurality of semiconductor laser having different wavelengths, an objective lens, an actuator for moving said objective lens to cause it t to approach or keep away from a recording surface of an optical disk, a spherical aberration corrector for correcting spherical aberrations of laser beams and photodetectors for detecting reflected rays from said optical disk;
- a drive circuit for actuating said semiconductor lasers and drive circuits for moving said actuator and said spherical aberration corrector, respectively;
- a signal processing circuit for generating signals from the reflected rays detected by said photodetectors;
- and
- a system controller for outputting a control signal to said drive circuit adapted to move said actuator so as to move aid objective lens in relation to said optical disk, outputting controls signals for activating said plurality of lasers of different wavelengths to said drive circuit and a control signal for controlling said spherical aberration corrector to said drive circuit and discriminating the kind of said optical disk from signals generated from said signal processing circuit,
- said spherical aberration corrector being operative to correct spherical aberrations in correspondence with respective ones of said plurality of semiconductor lasers.
Dependencies are inferred from the claim text.