| 摘要 |
PURPOSE:To obtain a rewritable optical disk by making a recording medium of metal or alloy which has at least two kinds of crystal structures in a solid state and holds the crystal structure in one temperature range even in the other temperature range and/or have mutually different volumetric variation in a crystal state. CONSTITUTION:The 1st layer which has a heat absorbing or accumulating function is provided on a plastic plate which has a reinforcing function, the 2nd layer which has a color tone recording function is provided thereupon, and the 3rd layer which protects it is formed. In this case, the recording medium is made of the metal or alloy which has at least two kinds of crystal structures in the solid state and holds the crystal structure in one temperature range even in the other temperature range and/or mutually different volumetric variation in the crystal state. Consequently, an erasure type photorecording disk is manufactured by using Ag-Zn alloy which causes no harm to living creatures and the effective utilization of write power and reduction in write temperature are attained. |
