Layered photochromic composition and device
US9310541B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 13, 2013 |
| Grant date | Apr 12, 2016 |
| Priority date | — |
| Expiry date | Jul 9, 2033 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B5/22
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An optical power-limiting passive (self-adaptive) device and method for limiting optical power transmission in lenses and windows, using layers of different photochromic compositions that exploit the full solar ultraviolet (UV) and short visible light spectrum. While a typical single photochromic material is activated by a UV band of wavelengths, e.g. 340 to 380 nm, adding a layer of photochromic material that is activated by an additional band of wavelengths, e.g., 380 to 420 nm, allows the efficient use of a wider band of solar UV and short visible light, e.g., 340 to 420 nm, thus enhancing the photochromic response to solar light.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.