Numerical aperture limiter
US6624956B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Oct 13, 2000 |
| Grant date | Sep 23, 2003 |
| Priority date | — |
| Expiry date | Oct 13, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J2005/0077
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The invention provides a numerical aperture limiter for an optical thermal imaging system, comprising at least one pair of wedge-like prisms made of a transparent material having a known index of refraction, the prisms of the pair being disposed in close mutual proximity and in opposite orientation with the narrow end of one prism adjacent to the wide end of the other prism, the prism surfaces facing one another of the pair of prisms being spaced apart from one another by a distance at least equal to the wavelength of the light used by the imaging system, with the vertex angle of each one of the prisms being a function of the desired numerical aperture and the index of refraction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.