Optical data recording disc with protrusion between clamping area and center hole

• US 20080016523A1
• Filed: 09/12/2007
• Published: 01/17/2008
• Est. Priority Date: 09/05/2002
• Status: Active Grant

• Current Assignee: Eiji Ohno, Kazuhiro Hayashi, Masanari Mohri
• Original Assignee: Eiji Ohno, Kazuhiro Hayashi, Masanari Mohri
• Inventors: Ohno, Eiji, Hayashi, Kazuhiro, Mohri, Masanari
• Granted Patent: US 7,409,699 B2
• Time in Patent Office: Days
• US Class Current: 720/718
• CPC Class Codes: B29C 2045/2661 The thickness of the mould cavity being changeable in radial direction B29C2045/2667 takes precedence
• CPC Class Codes: B29C 2045/2667 Particular inner or outer peripheral portions of the substrate
• CPC Class Codes: B29C 45/263 with mould wall parts provided with fine grooves or impressions, e.g. for record discs
• CPC Class Codes: B29D 17/005 Producing optically read record carriers, e.g. optical discs
• CPC Class Codes: B29L 2017/005 CD''s, DVD''s
• CPC Class Codes: G11B 17/0284 by clampers
• CPC Class Codes: G11B 23/0035 means incorporated in the disc, e.g. hub, to enable its guiding, loading or driving means for driving the head G11B21/06; guiding the disc for centering or locking G11B17/022; turntables or spindles for driving G11B19/2009
• CPC Class Codes: G11B 7/121 Protecting the head, e.g. against dust or impact with the record carrier
• CPC Class Codes: G11B 7/24003 Shapes of record carriers other than disc shape
• CPC Class Codes: G11B 7/24097 Structures for detection, control, recording operation or replay operation; Special shapes or structures for centering or eccentricity prevention within laminated discs G11B7/24021; Arrangements for testing, inspecting or evaluating; Containers, cartridges or cassettes
• CPC Class Codes: G11B 7/263 Preparing and using a stamper, e.g. pressing or injection molding substrates production of optical record carriers, e.g. optical discs B29D17/005

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.

Claims

1. An optical disc with a center hole, the optical disc comprising:

a signal substrate;

a signal recording layer for storing data;

a transparent protective layer 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, and

said protrusion is disposed at an area of the optical disc between the center hole and the clamping area,

wherein the signal substrate has a 1.1 mm thickness, and

the transparent protective layer has a 100 μ

m thickness.

2. An optical disc according to claim 1, wherein the height of the protrusion from a surface of the clamping area is 0.20 mm or less.

3. A playback device for playback of the information from the optical disc according to claim 1, wherein the optical disc is clamped on the clamping area, and the optical disc is rotated during playback,

wherein the data transfer rate during playback is higher than the Digital Versatile Discs media.

4. A recording device for recording the information onto the optical disc according to claim 1, wherein the optical disc is clamped on the clamping area, and the optical disc is rotated during recording,

wherein the data transfer rate during recording is higher than the Digital Versatile Discs media.