Holographic disk scanner
US4235504A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 9, 1977 |
| Grant date | Nov 25, 1980 |
| Priority date | — |
| Expiry date | Dec 9, 1997 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S359/90
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A light scanning apparatus comprises a disk having a plurality of holograms, and a laser beam source for radiating and directing a laser beam (which functions as a reproduction wave) onto the holograms in a sequential order, wherein each of the holograms converges the laser beam toward a corresponding focal point. While the disk and the laser beam are moved relative to each other, the focal point scans an object to be scanned in a particular scanning direction. The laser beam acting as a reproduction wave is preferably a spherical wave laser beam. The holograms are constructed by a process in which both a spherical wave laser, acting as a reference wave, and a plane wave laser are applied to a photosensitive layer which is to be constructed as the hologram, in which process the plane wave laser beam is applied onto the photosensitive layer at a predetermined gradient forming an offset angle between the direction in which the plane wave laser is oriented and the direction in which the photosensitive layer extends.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.