| 摘要 |
PURPOSE:To expand an erasing power margin, and to record a signal at a high quality on a recording film by irradiating an optical disk by means of laser power >=1.5 times of the laser power, which is obtained when the optical disk is irradiated with a light beam and an amorphous phase emerges. CONSTITUTION:The laser power is assumed as P0 which makes amorphous phase emerge when the optical disk is irradiated with the laser power directly and continuously, the optical disk is irradiated with the power P1>=1.5XP0. In such a way, erasing can be made to correspond to the intermediate state between a crystal state and an amorphous state. Thus an erasing characteristic can be improved, the erasing power margin is expanded, and a phase changing medium can be recorded and erased at a high quality and at high efficiency. |
