US 6,962,668 B2Granted

Double-sided digital optical disk and method and apparatus for making

AssigneeDPHI Acquisitions, Inc.

InventorsBrian S. Medower, Michael F. Braitberg, David H. Davies

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Abstract

A digital optical information disk contains content and/or non-content information on both sides of a single substrate produced by a process that embosses the surfaces of both sides substantially simultaneously. Simultaneous molding substantially eliminates the need for lamination when two or more data layers are to be provided. Preferably, the disk is relatively small, such as less than 50 mm in diameter and can replicate marks or features with a z-dimension magnitude of about 80 mm or more. The disk remains within a specified opto-mechanical range of an optical transducer and has little, if any, non-planarity (warp) or other distortion. The disk can be used for reading pre-written or mastered content, e.g., in a user's device, and/or can include information or features that permits or supports utility functions, allowing the user to record data thereon such as tracking, sector, location, timing, synchronization features or combinations thereof. Preferably, the disk is formed by an injection-only technique, although it is possible to provide suitable disks by an injection-compression technique as well.

Claims18

Dependent claims

A method for producing a digital optical disk which has first and second sides, the method comprising:

positioning first and second stampers, said first and second stampers defining first and second stamper planes, said positioning resulting in said first and second stamper planes being a first distance apart, said first stamper having first stamper marks at least partially out of said first stamper plane, said second stamper having second stamper marks at least partially out of said second stamper plane;
injecting an initially fluid molding material between said first and second stampers, wherein said molding material substantially fills at least a region having a first diameter;
wherein said molding material at least partially hardens to provide a first disk with a first side embossed with at least first disk marks corresponding to said first stamper marks and a second side embossed with at least second disk marks corresponding to said second stamper marks, said first and second embossed sides being produced substantially simultaneously;
positioning said first and second stamper such that said first and second stamper planes are a second distance apart, greater than said first distance;
removing said first disk from between said first and second stampers;
determining a concentricity of said first and second sides of said first disk;
based on said determination, re-positioning said first and second stampers;
re-injecting an initially fluid molding material between said re-positioned first and second stampers, wherein said molding material substantially fills at least the region having a first diameter;
wherein said re-injected molding material at least partially hardens to provide a second disk with a first side embossed with at least first disk marks corresponding to said first stamper marks and a second side embossed with at least second disk marks corresponding to said second stamper marks, said first and second embossed sides of said second disk being produced substantially simultaneously and having reduced concentricity compared to said first disk;
and
wherein said first disk marks are readable by providing light to said first side without said light first passing through said second side and wherein said second disk marks are readable by providing light to said second side without said light first passing through said first side.

8 more elements

A method for producing a digital optical disk which has first and second sides, the method comprising:

positioning first and second stampers, said first and second stampers defining first and second stamper planes, said positioning resulting in said first and second stamper planes being a first distance apart, said first stamper having first stamper marks at least partially out of said first stamper plane, said second stamper having second stamper marks at least partially out of said second stamper plane;
injecting an initially fluid molding material between said first and second stampers, wherein said molding material substantially fills at least a region having a first diameter;
wherein said molding material is least partially hardens to provide a first disk with a first side embossed with at least first disk marks corresponding to said first stamper marks and a second side embossed with at least second disk marks corresponding to said second stamper marks, said first and second embossed sides being produced substantially simultaneously;
positioning said first and second stamper such that said first and second stamper planes are a second distance apart, greater than said first distance;
removing said first disk from between said first and second stampers;
wherein said first disk marks are readable by providing light to said first side without said light first passing through said second side and wherein said second disk marks are readable by providing light to said second side without said light first passing through said first side;
adjusting a lateral position of said first stamper with respect to said second stamper, said adjusting including comparing concentricity of said first and second sides and moving at least a first of said stampers;
and
re-injecting an initially fluid molding material between said adjusted first and second stampers, wherein said molding material substantially fills at least the region having a first diameter;
wherein said re-injected molding material at least partially hardens to provide a second disk with a first side embossed with at least first disk marks corresponding to said first stamper marks and a second side embossed with at least second disk marks corresponding to said second stamper marks, said first and second embossed sides being produced substantially simultaneously.

7 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/290,116Filed 6 Nov 2002 · continuation
Priority: 31 Aug 2000
Published: US 2003/0152018 A114 Aug 2003
Granted: 8 Nov 2005
Term ends: Not estimatedThe source records don’t support an estimate.

Classification3 codes

B29C 45/263
Moulds: with mould wall parts provided with fine grooves or impressions, e.g. for record discs
B29C 2045/2653
With mould wall parts provided with fine grooves or impressions, e.g. for record discs: using two stampers
B29C
Shaping or joining of plastics