| 摘要 |
PROBLEM TO BE SOLVED: To prevent an adhesive flowing out due to sticking of substrates from arriving at a central hole of a disk by providing a concentric circular shape projection part with a height smaller than this plate thickness on an inner peripheral part in the vicinity of at least one side central hole of an optical information member to be stuck to each other and providing a recessed part according to this projection part on the other side of this optical information member. SOLUTION: The concentric circular shape projection part with the height smaller than substrate thickness is provided on the inner peripheral part in the vicinity of the central hole of the substrate b, and the recessed part according to this projection part is provided on the substrate a. In an area of A, the projection part and the recessed part are respectively provided so that a space considering the thickness of the adhesive when the substrates a, b are pushed against each other is formed. In the area of B, the projection part and the recessed part are respectively formed so that the space narrower than the space formed in the area A is formed. Thus, since this disk is constituted so that the adhesive 3 flows into the area B after it is filled up into the area A, the outflow of the adhesive 3 is stopped on the circumference of the area A or B. |
