Thermally switched optical filter incorporating a refractive optical structure
US8643795B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 13, 2010 |
| Grant date | Feb 4, 2014 |
| Priority date | — |
| Expiry date | Apr 28, 2031 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F1/19
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A thermochromic, thermotropic, or thermoreflective filter relies on a mismatch between the index of refraction of a thermotropic material (e.g., a liquid crystal) and a substrate material that includes refractive or diffractive features. At colder operating temperatures, the refraction mismatches are eliminated or minimized such that the filter becomes transparent, whereas at high operating temperatures the refraction mismatches are increased such that for light at appropriate incidence angles, the structure becomes highly reflective. This filter has particular but not exclusive application as a temperature-controlled “smart mirror” for use in windows, walls, roofing, and other building materials.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.