Method and apparatus for solid state illumination
US8740406B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 24, 2012 |
| Grant date | Jun 3, 2014 |
| Priority date | — |
| Expiry date | Sep 28, 2032 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B21/204
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A light source includes two excitation light sources generating two respective excitation lights, a filter, and a wavelength conversion material. The second excitation light has a peak wavelength shorter than that of the first excitation light. The transmittance curves of the filter are dependent on the input angle. The first and second excitation lights are inputted to the filter at angles smaller than a first threshold angle, and angles between the first and a third threshold angle, respectively. Both excitation lights pass through the filter to excite the wavelength conversion material, which generates a converted light but reflects some of the excitation lights. Part of the reflected first excitation light reaches the filter at input angles greater than a second threshold angle and is reflected by the filter back to the wavelength conversion material for recycling. The third and second threshold angles are greater than the first threshold angle.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.