Illumination device and method for laser projector
US6870650B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 4, 2003 |
| Grant date | Mar 22, 2005 |
| Priority date | — |
| Expiry date | Jun 4, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B5/32
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Systems and methods for providing illumination suitable for imaging devices such as laser projection systems. In one embodiment, a highly collimated (e.g., laser light) beam is passed through a holographic diffuser to create a well defined cone angle for the light emanating from each point on the diffuser. This light is focused into an illumination image that is controlled by the prescription of the diffuser. In one embodiment, the image is a uniformly intense rectangle having a 4:3 aspect ratio to match an imager for a projection display. The diffuser prescription and resulting illumination image can be selected to match any desired imager. The present systems and methods may provide the advantages of high level of light efficiency, reduction or elimination of speckle and “worminess” and reduction or elimination of cosine4 and gaussian intensity falloff, all of which are common in prior art designs.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.