Method and system for multi-spectral imaging in the visible and infrared spectrums
US5781336A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 28, 1995 |
| Grant date | Jul 14, 1998 |
| Priority date | — |
| Expiry date | Nov 28, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B13/146
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Multi-spectral images are detected using a refractive objective lens system. Magnesium oxide (MgO) and calcium fluoride (CaF.sub.2) lenses are used to image scenes in both the visible and infra-red (IR) spectrums. The inventors have discovered that the combination of magnesium oxide, only recently made available in a pure crystal form, and calcium fluoride can be used to fabricate an objective lens for imaging objects in both the visible and infra-red spectrums. Moreover, the combination of magnesium oxide and calcium fluoride results in a super-achromatic condition across visible and infra-red spectrums. This chromatically-corrected spectral range includes wavelengths between 0.4 and 5.9 microns which covers medium-wave IR (MWIR), short-wave IR (SWIR), and the near-IR/visible windows. Combinations of MgO and CaF.sub.2 lenses are used in different compound objective lens designs including doublet, Petzval, inverted telephoto, and telephoto arrangements. Visible and/or IR applications for the multi-spectral objective lens system include telescopes, reconnaissance planes, satellites, forward-looking IR (FLIR) and staring sensor systems, night-vision goggles, and other optic and/or el…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.