| 摘要 |
PURPOSE:To improve the corrosion resistance of a recording medium without spoiling its characteristics by forming a boron nitride film on one or both sides of an optical recording layer. CONSTITUTION:A boron nitride film 7 is formed on a write-side substrate 1a, and a recording layer 3, boron nitride film 8, and reflecting film 5 are provided and stuck on an external substrate 1b through an adhesive layer 6. The write- side substrate and external substrate may use any materials such as glass and plastic, and when a plastic substrate is used, this invention is effective because moisture hardly enters it. The boron nitride film is provided preferably to both sides of the recording layer, but may be formed only on one side. The fil thickness of the boron nitride film is preferably 500-3,000Angstrom ; dump resistance effect is insufficient below 500Angstrom and evil influence is exerted upon the magnetic characteristics of the recording layer above 3,000Angstrom . |
