Projection screen and system for large-surface images
US6462869B1 · kind B1 · utility
Inventor
Key dates
| Filing date | Nov 30, 2000 |
| Grant date | Oct 8, 2002 |
| Priority date | — |
| Expiry date | Nov 30, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B21/62
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A projection screen (30) for representation of images by back-projection comprises a plurality of holographic-optical elements (10) arranged in one plane. The holographic-optical elements are illuminated by a projector (14) comprising three projection devices (22,24,26). Each projection device (22,24,26) generates a light bundle (16,18,20) respectively including the chromatic components of an image to be projected. Each holographic-optical element (10) comprises at least one lens and one diffraction grating which are diffracted in such a manner by the different light bundles (16,18,20) that the holographic-optical element (10) will emit an exiting light bundle (28) with an identical exit angle (&bgr;) in the direction of the viewer (12). Such a projection screen will scatter the light only to a small extent so that the projection screen can be used also at daylight and for large-surface image projection.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.