COMPOSITE OPTICAL DISK STRUCTURAL BODY

摘要

PURPOSE: To obtain a composite optical disk structural body having little warpage and deformation which is suitable for high-density recording. CONSTITUTION: A single-face optical disk is produced by forming an aluminum reflecting film 4 in a data recording area 3 formed on one surface of a plastic disk 1 having a center hole and then forming a protective layer 6 on the aluminum reflecting film 4. A pair of these single-face optical disks are laminated to make one body with the protective films 6 facing each other. The laminating face of the single-face optical disk consists of the surface 6a of the protective film 6 and the surface 1c of the light-transmitting disk substrate between the protective film 6 and the center hole. A step D having step depth d is formed on each single-face optical disk of the pair so that the step D makes the transparent disk substrate surface 1c in the same plane as the protective film surface 6a.