| 摘要 |
PURPOSE: To prevent production of irregular film thickness of a protective layer and to improve productivity of an optical disk by forming a multilayered structure in such a manner that the small circle of the center hole of a (n+1)-th protective layer is larger than the small circle of the center hole of a n-th protective layer. CONSTITUTION: This optical recording medium consists of an optically transparent disk type substrate 2 having a center hole 3, a recording layer 4 which is annular and concentric with the substrate 2, and protective layers 5, 6 which are annular and concentric with the substrate 2 and is formed on the recording layer 4. The diameter of the center aperture of the protective layers 5, 6 is made larger than the diameter of the center hole 3 of the substrate. Moreover, the aperture 7 of the protective layer 6 which is the third (n=2) counted from the recording layer 4 is formed to have larger diameter than the aperture of the second layer (n=1) counted from the recording layer 4. Thereby, in the production process of the magneto-optical recording medium, the position for coating a resin to form the multilayered protective film can be easily controlled, production of irregular film thickness of the protective layer is prevented, and productivity of the optical disk is improved. |
