| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical recording medium of high sensitivity wherein reflectivity after recording of both recording layers satisfies a specification and recording sensitivity of both recording layers are improved in the two layer type optical recording medium capable of corresponding to high speed recording. <P>SOLUTION: In the write-once type optical recording medium wherein a first substrate formed by layering a first recording layer comprising an organic dyestuff and a first translucent reflection layer and having a guide groove and a second substrate formed by sequentially layering at least a second reflection layer, an inorganic film layer, a second recording layer comprising an organic dyestuff and an inorganic film layer are provided via a transparent intermediate layer so that both substrates are located on the outer sides, the reflectance of the second recording layer after recording of the first recording layer is increased as compared with that before recording, difference between the reflectivity (R1) of the first recording layer and the reflectivity (R2) of the second recording layer after recording of the first recording layer is within 0.03 and possible recording linear speed is 31 m/s or more. The reflectivity after recording means the reflectivity of an upper end of a signal amplitude after recording and difference between reflectivity is shown by ¾R1-R2¾/(R1+R2). <P>COPYRIGHT: (C)2007,JPO&INPIT |
