| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical recording medium which attains a high multi- speed recording and a high speed CAV recording and has high shelf reliability. SOLUTION: The optical recording medium having a lower protective layer, an optical recording layer, an upper protective layer and an optical reflection layer on a substrate is characterized in that the optical reflection layer consists of silver having film thickness D (Ag) and >=99 wt.% purity and has the relation with the thickness D (TL) of the upper protective layer expressed by the formula: 5×D (TL)<=D (Ag)<=15×D(TL), that when the composition formula of alloy to be a principal component of the optical recording layer is expressed by (Ag and/or Ge)α(In and/or Ge and/or Bi)βSbγTeδ, α, β, γ and δ (atom.%) satisfy the following relational formulae; 0.001<=α/(α+β+γ+δ)<=0.05; 0.01<=β/(α+β+γ+δ)<=0.10; 0.65<=γ/(α+β+γ+δ)<=0.85; 0.10<=δ/(α+β+γ+δ)<=0.27 and β/α>=1 (or 1.5) and that the optical recording layer has 7-12 m/s (or 14-21 m/s) upper limit linear speed of re-crystallization. |
