| 摘要 |
PURPOSE:To improve recording and reproducing characteristics, long-period reliability and quality by in a multi-layered structure including a reflection film forming the reflection film of a metal or metalloid such as titanium having low heat conductivity. CONSTITUTION:The 1st transparent dielectric film 2 consisting of transparent aluminum nitride, a thin rare earth transition metallic alloy film 3, the 2nd transparent dielectric film 4 and the reflection film 5 consisting of titanium are successively laminated and formed on a transparent substrate 1 and are made into multi-layered structure. The heat conductivity of the film 5 is made lower by using the titanium as compared to the case of using metal such as Al, Cu or Ag, by which the escape of the heat is decreased at the time of making recording by irradiating a laser to the recording medium and the recording and reproducing characteristics is improved. The long-period stability is made higher by the thermal stability and since the reflectivity is high as well, the reflection film having the substantial quantity of reflected light is obtd. to the regenerating system. The recording and reproducing characteristics are improved and the long-period reliability and quality are improved by forming the reflection film of the metal or metalloid having the low heat conductivity in the above-mentioned manner.
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