| 摘要 |
PROBLEM TO BE SOLVED: To accurately perform compensation of intensity of a laser beam at the time of recording information. SOLUTION: Reflected light from a pit part of an optical disk 1 in recording information is received by a photo-detector 21b, the maximum value of intensity of reflected light of the pit part and intensity of reflected light after the reference time width elapses from the tip of the pit part are detected through a peak detecting circuit 25 and a sample-and-hold circuit 26, the maximum value of intensity of reflected light of plural pit parts and sample intensity of reflected light are detected over several frames in an actual recording region at the time of start of recording information in an optical disk. Based on this detected result, the maximum value of intensity of reflected light being the reference value and sample intensity of reflected light are obtained, after the time of start of recording information, the maximum value of intensity of reflected light from the pit part and sample intensity of reflected light are detected, this detected result is compared with the reference value, and running OPC (Optimum Power Control) for compensating intensity of a laser beam is performed based on the compared result. |
