| 摘要 |
PURPOSE:To obtain an optical disk that is a proper circle, and having a center hole with small eccentricity, by molding a substrate and a metal laminated disk member separately, joining both members over entire main planes, and fixing them tentatively while a first bonding agent is hardened. CONSTITUTION:A guide groove spiral 18 is formed concentrically for a large circular center hole on one main plane of a transparent circular substrate 7 having a large circular center hole 8, and the metal laminated disk member 1 having a small center hole 3, the inside diameter of which is smaller than that of the large circular center hole 8, and having an outside diameter larger than the inside diameter of the large circular center hole 8, is formed. Next, the small center hole 4 of the metal laminated disk member 1 is positioned concentrically for the circular substrate 7, and the metal laminated disk member 1 is placed on one main plane of the circular substrate 7 through a first bonding agent 9. Next, after a second bonding agent 10 is arranged in the neighborhood of the surface of the circular substrate 7 positioned at the edge side plane of the metal laminated disk member 1, the second bonding agent 10 is hardened before the hardening of the first bonding agent 9, and thereby, the metal laminated disk member 1 and the circular substrate 7 are fixed tentatively. In this way, it is possible to form the optical disk having the center hole formed in an accurate proper circular shape, and with small eccentricity. |
