Optical disk substrate with land planes of uniform height
US5582891A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 15, 1993 |
| Grant date | Dec 10, 1996 |
| Priority date | — |
| Expiry date | Jun 15, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/21
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method of making a stamper uses a photoresist disk cut by the application of a laser beam on the land planes thereof, or a stamper which is different in depth between the land plane on the internal peripheral side with respect to the prepit portion and the land plane on the external peripheral side. A method of making an optical disk substrate includes the steps of using a stamper, and molding a transparent plastic material with an injection molding method. A stamper capable of sufficiently transferring the prepits and guide grooves on the optical disk substrate with the correction of right and left inequality of the prepits, and the method of making it, and a superior optical disk substrate and a method of making it can be realized.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.