| 摘要 |
PURPOSE:To decrease disk noises and signals which remain without being erased at the time of rewriting of information and to stabilize tracking by specifying the heat conductivity of inorg. protective layers formed on a recording film and at least one side of the recording film. CONSTITUTION:The inorg. protective layers are so formed that the heat conductivity thereof is >=2J/m.s.k at 273K. The heat conductivity of at least one of the protective layers is specified within this range in the case of providing said layers on both faces of the recording film. The inorg. protective layers may be of one-layered structure or the structure in which >=2 layers are combined; however, the escape of the heat applied by laser light increases too much and the greatly deteriorated recording sensitivity is caused if the heat conductivity is excessively large. The heat conductivity of the inorg. protective layers is, therefore, <=200J/m.s.k at 273K. The accumulation of the heat of the recording medium by laser projection is thereby suppressed and the disk noises and the signals remaining without being erased at the time of recording and rewriting of information are decreased. |
