| US 7,583,572 B2 | ||
| Apparatus and method for calibrating laser power in an optical disk apparatus | ||
| Kenji Akahoshi, Yokohama (Japan); Atsushi Saito, Hino (Japan); Makoto Nihei, Tokyo (Japan); and Junichi Ishii, Narashino (Japan) | ||
| Assigned to Hitachi, Ltd., Tokyo (Japan); and Hitachi-LG Data Storage, Inc., Tokyo (Japan) | ||
| Filed on Mar. 24, 2004, as Appl. No. 10/808,922. | ||
| Claims priority of application No. 2003-355801 (JP), filed on Oct. 16, 2003. | ||
| Prior Publication US 2005/0083802 A1, Apr. 21, 2005 | ||
| Int. Cl. G11B 7/00 (2006.01) | ||
| U.S. Cl. 369—47.51 [369/53.26] | 9 Claims |
| 1. 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.
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