| 摘要 |
PURPOSE:To obtain a medium having high absorptivity for light of a dye layer and high reflectance be providing a dye layer having specified properties on a resin substrate and providing a reflecting layer and a protective layer thereon. CONSTITUTION:The medium consists of a resin substrate 2, dye layer 3, reflecting layer 4 and protective layer 5 successively deposited. The dye layer 3 has refractive index (n) of 1.8 - 3.2 and extinction factor (k) of 0.04 - 0.12 for 700 - 850 wavelength, and 100 - 1,500 Angstrom thickness in the area for light irradiation. When the medium is irradiated with light for recording, a mixture part 85 comprising the substrate material and decomposed dye is formed. At the same time, a part 8 having low refractive index and containing the decomposed dye from the mixture part 85 is formed. When the medium is irradiated with light for reproducing from the substrate side 2, reflectance from nonrecorded area is >60%, while reflectance from recorded area is as smaller as <40% of the reflectance from nonrecorded area. By this method, the low refractive index part 8 and the mixture part 85 are formed between the sub strate 2 and the dye layer 3 by irradiation of recording light and this area irradiated with light gives significantly decreased reflectance. Thereby, preferable optical record ing can be realized with reproducing performance according to CD standards. |
