Optical data recording disc with protrusion between clamping area and center hole
AssigneePanasonic Corporation
InventorsKazuhiro Hayashi, Eiji Ohno, Masanari Mohri
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Abstract
A disc-shaped optical data recording medium has a signal recording layer for reading and/or writing data using light, and a 10 μm to 200 μm thick transparent protective layer disposed over the signal recording layer. The optical data recording medium includes a protrusion projecting from a surface of the transparent protective layer on a light-incidence surface side to which light is emitted to the signal recording layer. The protrusion is disposed in an area between a center hole and a clamping area where the optical data recording medium is held when reading and/or writing data in the signal recording layer.
Claims3
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 thickness of 10 μm to 200 μm disposed over said signal recording layer;
- and
- a protrusion projecting from a surface of said transparent protective layer, wherein
- the optical disc has a clamping area adapted to be held when reading and/or writing data in the signal recording layer, the clamping area being located between a 22 mm diameter and a 33 mm diameter, and
- said protrusion is disposed at an area of the optical disc between the center hole and the clamping area, the area being between a 17.5 mm inside diameter and 21.0 mm outside diameter.
Dependencies are inferred from the claim text.