Patent ID: 7401347
Filing Date: 2008-07-15
Classification: B29C,B29D,B29L,G11B

Abstract:
1. An optical disc with a center hole having a 15 mm diameter, the optical disc comprising: a signal substrate; a signal recording layer for storing data; a transparent protective layer having a 10 μm to 200 μm thickness disposed over said signal recording layer; and a protrusion projecting from a surface of said transparent protective layer, wherein a signal area of the optical disc is located over said signal recording layer, a clamping area of the optical disc is located between the signal area and the center hole, said transparent protective layer is located over the signal area, the clamping area, and an area inner than the clamping area, said protrusion is disposed at an area between a 17.5 mm inside diameter and 22.0 mm outside diameter of the optical disc, the area being located between the center hole and the clamping area, and said protrusion is formed on the area by bonding thereto a part made of a material, which is different from said signal substrate, in the shape of said protrusion.