| 摘要 |
PURPOSE:To execute recording without increasing the output of a recording laser power and to execute reproducing with a high laser power so as to lower the error rate of reproduced information by adding a pair of electrode layers and a heater layer to the optical disk medium. CONSTITUTION:Since a recording layer 2 is low in sensitivity at the time of executing recording, a voltage is impressed to the electrode layers 3, 3' and the layer 2 is irradiated with the recording laser power while the layer is kept heated by the heater layer 4. The recording is possible with the laser power lower by as much as the layer 2 is heated by the layer 4 at this time. The optical medium disk is irradiated with the laser power for reproduction without applying the voltage to the layers 3, 3 at the time of executing reproduction. Since the layer 2 is low in sensitivity, the reproduction is executable with the high laser power. The recording is executed without increasing the output of the recording laser power and the reproduction is executed with the high laser power in this way, by which the error rate of the reproduced information is lowered. |
