Light recovery for projection displays
US6840623B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Apr 24, 2002 |
| Grant date | Jan 11, 2005 |
| Priority date | — |
| Expiry date | Apr 24, 2022 |
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 includes a reflector having a first and a second focal points. A source of electro-magnetic radiation at the first focal point emits rays of radiation that reflect from the reflector and converge substantially at the second focal point. A retro-reflector reflects radiation that does not impinge directly on the relector toward the reflector. An input surfacre of a light pipe is disposed proximate to the second focal point to collect and transmit sustantially all of the radiation. A first reflector is disposed proximate to an output surface of the light pipe to transmit a first band of radiation while reflecting a second and third bands of radiation. A second reflector transmits the second band of tadiationn while reflecting the first and third bands of radiation. A third reflector transmits the tird band of radiation while reflecting the first and second bands of radiation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.