| 摘要 |
PURPOSE:To allow the execution of not only reversible recording but also unerasable recording without inconveniences even if a rigid surface protective layer exists by laminating a recording layer, a metallic layer having the m.p. higher than the m.p. of the recording layer and further the protective layer having the m.p. higher than the m.p. of the metallic layer. CONSTITUTION:The recording layer 3 is formed of a metal and the metallic layer 4 having the m.p. between the m.p. respectively possessed by the recording layer 3 and the protective layer 5 is provided between the recording layer 3 and the protective layer 5. The recording or erasing is executed by selecting the intensity of a laser beam. The intensity of the laser beam is so selected as to attain the temp. higher than the m.p. of the recording layer 3 and lower than the m.p. of the 2nd metallic layer 4 and the recording layer is irradiated with such laser beam at the time of executing the ordinary reversible recording. The intensity of the laser beam is so selected that the recording layer 3 attains the temp. higher than the temp. of the 2nd metallic layer 4 and the temp. lower than the m.p. of the protective layer 5 at the time of executing the irreversible recording, and the recording layer is irradiated with such laser beam. The reproducing of the record is executed by irradiating the recording layer 3 with the laser beam of such intensity at which the recording layer attains the temp. below the m.p. thereof. |
