| 摘要 |
PROBLEM TO BE SOLVED: To perform highly reliable recording/reproducing by an inexpensive binary circuit by changing recording power by a CPU or the like for controlling an entire circuitry according to the number of times of rewriting data and controlling the change of a recording characteristic. SOLUTION: The phase change type optical disk 1 performs data recording/ reproducing by a laser light flux LB from an optical pickup 2 and a CPU 51 controls the entire operation of a circuit system 5. Semiconductor laser control and driving circuits 52 and 53 turns on a semiconductor laser 3 by recording power for recording and by reproducing power for reproducing based on the command of the CPU. The circuit system 5 reproduces the data of a block to be recorded, confirms the number (n) of rewriting times and records this by recording power obtained by multiplying the optimal recording power by a specified function according to the number (n). Thus, the change of a recording characteristic is controlled by the number (n), the asymmetric and stepped changes of the reproducing signal are prevented and recording enabling highly reliable reproducing is performed even by an inexpensive binary circuit 56. |
