| 摘要 |
PROBLEM TO BE SOLVED: To provide the power adjusting method of a laser beam reducing an error rate. SOLUTION: A CPU 1 calculates an asymmetry from the reproduced signal of data written with respect a WORM(write once read many) disk 12 by controlling a laser beam source 4 and a first photodetecting part 7 and calculates an optimum power by hitting the table of the value of this asymmetry with a second-order function. A laser power control part 3 makes the laser beam source 4 emit a light by the optimum power to perform a write with respect to the WORM disk 12. |
