| 摘要 |
PURPOSE: To determine optimum laser beam intensity and to prevent the erasing defect of overwrite recording by changing the laser beam intensity ratio of a low level and high level according to an ambient temp., and executing test recording. CONSTITUTION: A magneto-optical disk is set at a recording and reproducing layer and the information on recording laser beam intensity is read into the layer from a prescribed region. Simultaneously, the ambient temp. is measured and the laser beam intensity ratio of the low level and the high level is set from these values. Test recording is executed by stepwise changing the laser beam intensity of the low level and the high level without changing the intensity ratio in accordance with the patterns for test recording to alternately repeat continuous short marks and continuous long marks. Next, the difference between the amplitude center of the reproduced signals of the continuous short marks and the amplitude center of the reproduced signals of the continuously long marks is measured. The intensity of the laser beam at which the value is made zero is determined. The intensity of the laser beam of the low level and the high level is then determined. |
