Illuminators using reflective optics with recycling and color mixing
US7234820B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 11, 2005 |
| Grant date | Jun 26, 2007 |
| Priority date | — |
| Expiry date | Nov 29, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/0068
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Various optical techniques are described for obtaining a specified light output from an LED source. One technique uses a parabolic reflector surrounding an LED or LED array to create a collimated beam, and the light exit opening of the parabolic reflector is defined by a reflective disc with an opening of the desired size. Any generated light that is outside of the opening is reflected back into the parabolic reflector and re-reflected until the light exits the opening. For mixing different light colors from different LEDs or energized phosphors, a mixing tunnel is used. The mixing tunnel includes angled dichroic mirrors or angled polarizer mirrors that selectively reflect and pass selected colors or polarizations of light to a single output port of the mixing tunnel. Efficient and compact ways to energize phosphors are also described. Other optical techniques are also described.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.