Full-color zero-order suppressed diffraction optics diffusing screen/louver filter laminate
US5016950A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 5, 1988 |
| Grant date | May 21, 1991 |
| Priority date | — |
| Expiry date | Jul 5, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03H1/0465
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A full-color holographic screen laminate is disclosed, having a well-defined exit pupil, off-axis viewing capabilities, high and uniform gain, and low backscatter, and in addition the capabilities of blocking the zero-order beam and allowing full-color viewing. The laminate in one preferred form includes several layers, including a plano-convex focusing lens, a directional diffraction optics diffusing screen, and a thin plane-parallel laminate consisting of a plano-concave cylindrical lens, a slanted louver filter, and a plano-convex cylindrical lens. The lenses can be made out of contrast enhancement material. The louver filter is curved so that the louvers are oriented parallel to the line of sight across the entire louver surface. The plano-convex lens focuses the light, the diffusion screen bends and diffuses the light, the louver filter passes the diffracted light but blocks the zero-order light from entering the ambient, and the contrast enhancement lens increases the overall contrast of the screen.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.