| 摘要 |
PROBLEM TO BE SOLVED: To obtain a device capable of sufficiently coping with the speeding up and the contriving of the high density of an information recording by correctly recording recording bits, regardless of the variation of recording powers. SOLUTION: A prescribed signal is recorded by changing recording powers on a magneto-optical disk 1 and the power level PHth immediately before the high temp. level state of the disk 1 starts is detected, based on reproducing signal amplitudes detected in an amplitude detecting circuit 17 by reproducing the disk 1. Next, the value of a power level PL forming a low temp. level state is determined by a CPU 18 from the obtained PHth . Then, signals having different lengths are recorded on the disk 1 by changing recording powers. Next, the difference between intermediate values of peak values and the bottom values of reproducing signals having different lengths is detected by an asynmmetrical circuit 19 and a power level which forms a high temp. state in the disk 1 is determined by the CPU 18. Then, a signal is recorded by changing recording powers and the signal detected in a differentiation circuit 21 and a differential signal amplitude detecting circuit 22 is also outputted to the CPU 18 to be used for adjusting multi-valued power levels of a laser 5. |
