Phosphor converted light source having an additional LED to provide long wavelength light
US8395312B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Apr 19, 2010 |
| Grant date | Mar 12, 2013 |
| Priority date | — |
| Expiry date | Aug 2, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10H20/851
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A light source having first and second LEDs and a phosphor layer that converts light generated by the first LED is disclosed. The first LED emits light at a first wavelength. The layer of phosphor is illuminated by the first LED, the phosphor being excited by light of the first wavelength to convert light of the first wavelength to a band of wavelengths having wavelengths between the first wavelength and a second wavelength. The second LED emits light at a third wavelength that is greater than the first wavelength. The phosphor is not substantially excited by light of the third wavelength. The combined light from the phosphor, and first and second LEDs is perceived as being white by a human observer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.