| 摘要 |
PURPOSE:To erase old data without fail by setting a reproducing beam with preceding to an erasing beam and narrowing-down diaphragm with a same objective lens. CONSTITUTION:A laser 8 for reproducing is set preceding a laser 9 for erasing and both the beams are narrowed down by a same objective lens 10 and irradiat ed on a recording medium 11 an interval between the laser beam 8 and 9 is constant. When the old data are detected by the preceding reproducing beam 8 and an erasing pulse is generated with specified time difference, an irradiating pulse hits the center of a domain. Thus, the old domain can be erased without fail. |
