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AssigneeImation Corp.
InventorsChad R. Sandstrom, Douglas R. Plourde, Dean E. Sitz, Donald J. Kerfeld, John R. Johnson
Estimating the term…
An optical disk exhibiting no detrimental thickness increase (edge wedge effect) that arises at the outer diameter of an optical disk substrate during an injection molding manufacturing process, and an apparatus and method for making such a disk. The optical disk of the present invention is designed for use with an optical disk player, especially where the data on the optical disk is stored air incident. This optical disk includes a disk substrate made from a molded polymeric material. The disk substrate has a first major surface, a second major surface, and an outer edge. The first major surface of the optical disk includes a data region having an intermediate portion and an outer portion. The outer portion extends to the outer edge of the optical disk. The disk substrate has a thickness defined by the distance between the first major surface and the second major surface. The optical disk also includes an information layer covering the data region. In the present invention, the thickness of the intermediate portion of the data region is substantially equal to the thickness of the outer portion of the data region such that the outer portion of the data region is capable of being used by the optical disk player.
A disk molding apparatus for forming an optical disk in a disk molding process, wherein the apparatus reduces the edge wedge effect in the molded optical disk, the disk molding apparatus comprising:
A stamper for use in a disk molding apparatus that creates optical disks, the stamper comprising an information surface and a back surface, wherein the information surface of the stamper forms the first major surface of the disk substrate cavity, and the information surface produces a formatted surface relief pattern in the disk substrate during the molding process, and wherein the stamper includes a lip formed on an outer perimeter of the back surface of the stamper which causes flexing during the molding process to counter the molding edge wedge effect.
Dependencies are inferred from the claim text.