Light recovery for projection displays
US7232228B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 24, 2004 |
| Grant date | Jun 19, 2007 |
| Priority date | — |
| Expiry date | Dec 13, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/315
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A light recovery system for a projection display with a reflector having a first and a second focal points. A source of electro-magnetic radiation is disposed proximate to the first focal point of the reflector to emit rays of radiation that reflect from the reflector and converge substantially at the second focal point. A retro-reflector reflects at least a portion of the electromagnetic radiation that does not impinge directly on the reflector toward the reflector through the first focal point of the reflector to increase the flux intensity of the converging rays. A light pipe wit an input surface and an output surface is disposed with the input surface proximate to the second focal point to collect and transmit substantially all of the radiation. A PBS is disposed proximate to the output surface to collect and polarize substantially all of the radiation into a radiation of a first polarization and a second polarization. Radiation of the first polarization is transmitted, while radiation of the second polarization is reflected toward the output surface. A wave plate is disposed in a path of the radiation of the second polarization.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.