Holographic systems having reference beam coded holograms
US4018503A · kind A · utility
Inventors
Key dates
| Filing date | Jan 14, 1977 |
| Grant date | Apr 19, 1977 |
| Priority date | — |
| Expiry date | Jan 14, 1997 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S359/90
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
This invention is concerned with methods and apparatus for recording multiple exposure holograms on a film record and displaying reconstructed images of the separately recorded subjects. Means are provided, by the use of simultaneous application of multiple different reference beams, to reconstruct a plurality of images, each of which can be separately controlled in intensity or other random parameter. Also, the recording of the separate subjects can be controlled in a predetermined timed sequence, and the corresponding reconstruction of the plurality of images can be controlled in the same or different timing sequence. Means are provided for recording the separate subjects by keeping the subject and reference beam in fixed directions and rotating the plane of the recording film sheet or strip. Encoding of the hologram record is accomplished by means of a beam scrambler which introduces random parameters, e.g. intensity variations or random path length differences, in either the reference or object beam during the formation of the hologram. The same or identical random parameter means is used during reconstruction of the hologram to decode the identifying indicia.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.