| 摘要 |
PROBLEM TO BE SOLVED: To always make a data recording condition of an optical disk optimum and stable by controlling the intensity of recording laser beams, which irradiate a direct-read-after-write type optical disk during a data recording, so that the intensity follows up stain such as a fingerprint stuck on a recording surface and does not follow up the camming of the surface. SOLUTION: The device has a semiconductor laser diode 101 which emits first and second laser beams, a servo/RF photodiode 104 which receives the reflected light beams from a direct-read-after-write type optical disk and outputs electric signals representing the intensity of the beams, a B value detecting circuit 105 which detects the B value of the reflected light beams, a DRC detecting circuit 106 which detects DRC signals, a fingerprint detecting circuit 107 which detects stain such as a fingerprint based on the DRC signals, and an ROPC loop filter circuit 108 which selects a control speed and a control frequency band of ROPC based on the B value and the output of the circuit 107 and outputs a gain. |
