System and technique for making holographic projection screens
US5151799A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 11, 1991 |
| Grant date | Sep 29, 1992 |
| Priority date | — |
| Expiry date | Feb 11, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B5/32
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A fast, accurate system for manufacturing holographic projection screens. The invention (10) includes a mechanism (28) for moving holographic film (26) along a longitudinal axis thereof in a first direction. A mechanism (12) is provided for directing and maintaining an input beam (22) onto the film (26) as the film (26) is moved. The application of a reference beam (23) is then effective to create an interference pattern on the film (26) with the input beam (22). The mechanism (12) for maintaining the input image at a fixed location on the film includes a polygon shaped mirror mounted to rotate at a rate determined in accordance with the rate of movement of the film. An image stabilization system (40) is also provided which includes a detector (58) for monitoring an interference pattern created by the signal beam and the reference beam. Circuitry (60) is included for providing control signals in response to the detector (58) outputs. A phase shifter (44) induces a phase shift in the reference beam. A phase shifter positioning mechanism (46) adjusts the phase shifter (44) in response to the control signals so that the image is stabilized on the film (26) despite the movement thereof…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.