LED illumination system with polarization recycling
US8075140B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 2, 2007 |
| Grant date | Dec 13, 2011 |
| Priority date | — |
| Expiry date | Jan 13, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10H20/855
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A light engine has a light source front surface that emits non-collimated light. A collection lens collects the non-collimated light and provides incompletely collimated light. A collimating lens receives the incompletely collimated light and provides a collimated image. A non-orthogonal polarizing filter receives the collimated image and passes a polarized portion of the collimated image as a direct component of the polarized light engine image. The non-orthogonal polarizing filter reflects a recycled image back to the front surface. The non-orthogonal shape of the polarizing filter is selected according to the pattern of light on the light source front surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.