Rear projection screen with spatial varying diffusing angle
US7423808B2 · kind B2 · utility
4Cited by
3References
7Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Mar 12, 2007 |
| Grant date | Sep 9, 2008 |
| Priority date | — |
| Expiry date | Mar 12, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B21/625
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A Fresnel lens of the prior art is split into two Fresnel lenses to allow easier control of the horizontal and vertical viewing angles. In a second embodiment, the Fresnel lens is entirely eliminated. Instead, the diffuser contains elliptical microstructures so that the diffusing cones in orthogonal directions are different, eliminating the need for a Fresnel lens to perform this function. To compensate for the absence of the light collimation provided by the Fresnel lens, a diffuser with spatially varying diffusing angles is used.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.