| 摘要 |
PURPOSE:To permit an easy assembling operation and to improve the productiv ity of an optical disk by functioning a cylindrical part of a hub body fixed to a disk substrate as a guide for positioning in the stage of incorporating a counter plate disposed to face the substrate to the substrate. CONSTITUTION:A recording region consisting of a recording surface 1a by concentrical or spiral grooves and pit 2a by an Se-Te recording film 2b is formed to a transparent disk-shaped disk substrate 1 of the optical disk and a hub 4 is inserted to the central through-hole 3 of the substrate 1. The hub 4 is fixed by an adhesive agent 6 to the substrate 1. The hub 4 is constituted of a flange part 4a fixed by the adhesive agent 6 onto the substrate 1 and a cylindrical part 4b inserted into the central through-hole 3 to project down ward of the substrate 1. A center hole 5 is provided to the center of such cylin drical part 4b so as to project therefrom and a central insertion hole 8 is inserted onto the cylindrical part 4b of the hub 4 and is adhered. A protective plate (counter plate) 7 is disposed to the recording surface 1a of the substrate 1 via a gap 9. The assembling operation of the optical disk is thus made easy. |
