Patents Represented by Attorney, Agent or Law Firm Dick, Bronstein, Roberts & Cushman/Edwards&Angell LLP
  • Patent number: 6507559
    Abstract: An optical recording medium is an optical disk formed by bonding a substrate to a light transparent cover layer smaller in thickness than the substrate, and the optical disk includes one or more recording layer between the substrate and the light transparent cover layer. The light transparent cover layer is smaller in diameter than the substrate. Further, it is desirable that an outer edge of the substrate be higher than a between-edge part of the substrate. With this arrangement, a bonding surface of the substrate and the light transparent cover layer is not exposed out of an outer curved surface. Accordingly, it is possible to protect the bonding surface between the outer edge and the inner edge so as to increase strength against exfoliation of the light transparent cover layer.
    Type: Grant
    Filed: May 11, 2000
    Date of Patent: January 14, 2003
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Tetsuo Iwaki