Apparatus and method for calibrating laser power in an optical disk apparatus
AssigneesHitachi, Ltd., Hitachi-LG Data Storage, Inc.
InventorsKenji Akahoshi, Atsushi Saito, Makoto Nihei, Junichi Ishii
Life of this patent
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Abstract
Laser light irradiation can be performed on a recordable surface in a defocused state with a high-power laser beam with safety without incurring data destruction due to erroneous data recording or overwrite recording even in the recording on an eccentric disk or regardless of occurrence of wobbling of the disk surface. Laser irradiation is performed after moving an objective lens radially inwardly beyond a PCA located at an inner peripheral portion of the disk (or radially outwardly beyond the PCA located at an outer peripheral portion of the disk) by using a tracking coil.
Claims9
An optical disk apparatus for recording data on a recordable optical disk having a power calibration area and a recording management area both located on an inner periphery thereof, and an area located radially inwardly of the power calibration area and the recording management area, the optical disk apparatus comprising:
- a laser diode for emitting a laser beam;
- a laser diode driver module for driving the laser diode;
- an objective lens for constricting the laser beam;
- objective lens driving means for driving the objective lens in a radial direction of the recordable optical disk;
- a front monitor for detecting a portion of the laser beam emitted from the laser diode to monitor a laser power of the laser beam;
- and
- control means for controlling the laser diode driver module and the objective lens driving means,
- wherein said control means controls the objective lens driving means such that the laser beam is irradiated on the area in a defocused state, but is not irradiated on the power calibration area or the recording management area, while controlling the laser diode driver module for emitting the laser beam to observe an optical amount of the irradiation using the front monitor for the purpose of adjusting the laser power,
- wherein light returned from the area of the recordable optical disk is not substantially detected.
An optical disk apparatus for recording data on a recordable optical disk having a power calibration area located on an outer periphery thereof, and an area located radially outwardly of the power calibration area, the optical disk apparatus comprising:
- a laser diode for emitting a laser beam;
- a laser diode driver module for driving the laser diode;
- an objective lens for constricting the laser beam;
- objective lens driving means for driving the objective lens in a radial direction of the recordable optical disk;
- a front monitor for detecting a portion of the laser beam emitted from the laser diode to monitor a laser power of the laser beam;
- and
- a control circuit for controlling the laser diode driver module and the objective lens driving means,
- wherein the control circuit controls the objective lens driving means such that the laser beam is irradiated on the area in a defocused state, but is not irradiated on the power calibration area, while controlling the laser diode driver module for emitting the laser beam to observe an optical amount of the irradiation using the front monitor for the purpose of adjusting the laser power,
- wherein light returned from the area of the recordable optical disk is not substantially detected.
Dependencies are inferred from the claim text.