Infra red filter
US6252702A · kind A · utility
4Cited by
15References
17Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 8, 1998 |
| Grant date | Jun 26, 2001 |
| Priority date | — |
| Expiry date | Dec 8, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B5/22
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A phosphate glass doped with copper in an amount of less than 2% by weight is formed to produce a lens for use on external aircraft lights. The glass attenuates infra red radiation to a degree where it does not pose a danger of temporarily blinding a pilot wearing night vision goggles yet remains visible. The glass has little appreciable effect on light transmission in the visible spectrum. Conveniently, the glass can be formed by slumping at a softening temperature against a mold to produce intricate lens shapes. In addition, the glass is able to withstand conventional toughening processes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.