UV reflectors and UV-based light sources having reduced UV radiation leakage incorporating the same
US6686676B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 30, 2001 |
| Grant date | Feb 3, 2004 |
| Priority date | — |
| Expiry date | Apr 30, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10H20/882
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
UV reflectors incorporated in UV LED-based light sources reduce the amount of UV radiation emission into the surroundings and increase the efficiency of such light sources. UV reflectors are made of nanometer-sized particles having a mean particle diameter less than about one-tenth of the wavelength of the UV light emitted by the UV LED, dispersed in a molding or casting material surrounding the LED. Other UV reflectors are series of layers of materials having alternating high and low refractive indices; each layer has a physical thickness of one quarter of the wavelength divided by the refractive index of the material. Nanometer-sized textures formed on a surface of the multilayered reflector further reduce the emission of UV radiation into the surroundings. UV LED-based light sources include such a multilayered reflector disposed on an encapsulating structure of a transparent material around a UV LED, particles of a UV-excitable phosphor dispersed in the transparent material. Alternatively, the transparent material also includes nanometer-sized particles of a UV-radiation scattering material.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.