Light recycling illumination systems utilizing light emitting diodes
US7352124B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 28, 2004 |
| Grant date | Apr 1, 2008 |
| Priority date | — |
| Expiry date | Nov 19, 2025 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S362/80
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
This invention is an illumination system that incorporates a light emitting diode and a partially reflecting optical element. The light emitting diode emits internally generated light and reflects incident light with high reflectivity. The partially reflecting optical element transmits a first portion of the internally generated light and reflects a second portion of the internally generated light back to the light emitting diode, where the second portion is reflected by the light emitting diode. The partially reflecting optical element can be a non-absorbing reflecting polarizer or a wavelength conversion layer. Utilizing a partially reflecting optical element and light recycling can increase the effective brightness and the output efficiency of the illumination system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.