| 摘要 |
<P>PROBLEM TO BE SOLVED: To enable erasing information efficiently in a multi-layered optical recording medium having four or more phase change-type recording layers. <P>SOLUTION: By using a recording and reproducing optical system 100 for recording and reproducing information by irradiating a single track with a first beam 170 of a first wavelength and an erasing optical system 200 for erasing information by irradiating a plurality of tracks with a second beam 270 of a second wavelength longer than the first wavelength in a straddling manner, the first beam of the recording and reproducing optical system 100 is irradiated to a recording layer 14 to pull a focus signal and the second beam 270 of the erasing optical system 200 is focused on the recording layer 14 to be erased using the focus signal, thereby simultaneously erasing information of the plurality of tracks by the second beam 270. <P>COPYRIGHT: (C)2012,JPO&INPIT |
