Method and apparatus for copying holographic disks
US4790612A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 15, 1986 |
| Grant date | Dec 13, 1988 |
| Priority date | — |
| Expiry date | Sep 15, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/1362
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A multi-faceted holographic disk can be copied in a one-step process by using a source disk, actually a sandwich of two thin film layers of photosensitive material. The first thin film layer is capable of producing multiple reference beams simultaneously. The second thin film layers is a "master" copy of the disk to be copied. Both layers are produced using known off-axis holographic techniques. A target disk, having an unexposed film of photosensitive material is located ajacent the second thin film layer. The source disk is illuminated with coherent light, preferably in the form of a conical beam with an apparent point of origin on an axis through the common centers of the source and target disks. Several optical elements capable of producing the conical beam are illustrated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.