| 摘要 |
PURPOSE:To reduce a secular change of the reflectance of a reflecting film and to stably reproduced information over a long period by using a binary Al-Ti alloy or a ternary Al-Ti-Ag alloy to form the reflecting film on one side of a substrate. CONSTITUTION:One side of a substrate 1 has many pits 2, 2... corresponding to information to be recorded in a spiral line around the central axis. A reflecting film 3 of a binary Al-Ti alloy or a ternary Al-Ti-Ag alloy is formed on the substrate 1 so as to cover at least all the pits 2, 2.... The Ti in the film 3 inhibits the oxidation of the Al and suppresses the reduction of the reflectance of the film 3 due to oxidation. When the resulting optical disk is used, information can be stably reproduced over a long period without causing a bit error or nonreproducing. |
