Optical disc apparatus and optical disc discriminating method
AssigneesHitachi-LG Data Storage, Inc., Hitachi Consumer Electronics Co., Ltd.
InventorTakeyoshi KATAOKA
Life of this patent
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Abstract
In an optical disk having multiple layers for which a correction of spherical aberration is required, a spherical aberration correcting element is set to a predetermined spherical aberration correction amount; a laser light source is turned ON; an objective lens is swept; when it is discriminated that the optical disk has two or more layers, or has more than two information recording planes, the spherical aberration correction amount is changed into a spherical aberration correction amount suitable for information recording planes of three, or more layers; and the objective lens is again swept so as to discriminate a total layer number thereof.
Claims10
An optical disk apparatus for reproducing information from an optical disk, or recording information on the optical disk by using laser light, comprising:
- an objective lens which collects the laser light;
- an actuator which drives the objective lens;
- a detector which detects reflection light from the optical disk;
- a focusing error signal producing means which produces a focusing error signal (FES) from the reflection light detected by the detector;
- a spherical aberration correcting element which corrects spherical aberration occurred in the laser light;
- a control means which produces and outputs a focusing drive signal for controlling the actuator and a spherical aberration correcting element drive signal for controlling the spherical aberration correcting element;
- an actuator driving means which amplifies the focusing drive signal to supply electric power to the actuator;
- and
- a spherical aberration correcting element driving means which receives the spherical aberration correcting element drive signal to change a spherical aberration correction amount of the spherical aberration correcting element;
- wherein, in the case that the control means discriminates the optical disk having information recording planes, a total layer number of which is equal to or larger than a predetermined layer number, the control means performs a sweep process for moving the objective lens along a focusing direction a plurality of times while the spherical aberration correction amount of the spherical aberration correcting element is changed.
An optical disk discriminating method in an optical disk apparatus which reproduces information from an optical disk, or records information on the optical disk by using laser light, the optical disk apparatus comprising:
- an objective lens which collects the laser light;
- an actuator which drives the objective lens;
- a detector which detects reflection light from the optical disk;
- a focusing error signal producing means which produces a focusing error signal (FES) from the reflection light detected by the detector;
- a spherical aberration correcting element which corrects spherical aberration occurred in the laser light;
- a control means which produces and outputs a focusing drive signal for controlling the actuator and a spherical aberration correcting element drive signal for controlling the spherical aberration correcting element;
- an actuator driving means which amplifies the focusing drive signal to supply electric power to the actuator;
- and
- a spherical aberration correcting element driving means which receives the spherical aberration correcting element drive signal to change a spherical aberration correction amount of the spherical aberration correcting element;
- characterized in that, in the case that the control means discriminates the optical disk provided with information recording planes having the total layer number of the planes equal to or larger than a predetermined layer number, the control means performs sweep process of moving the objective lens along a focusing direction a plurality of times while the spherical aberration correction amount of the spherical aberration correcting element is changed each time.
Dependencies are inferred from the claim text.