Patent · US Expired

Thermal imagers

US4808823A · kind A · utility

9Cited by
1References
15Claims
0Family size

Assignee

Inventors

Key dates

Filing dateAug 11, 1987
Grant dateFeb 28, 1989
Priority date
Expiry dateAug 11, 2007

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG02B13/10
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

An anamorphic optical system for use in a thermal imager with a sprite detector includes two or more optical elements, preferably prisms, which are shaped and positioned so that change in their refractive index with temperature and/or wavelength results in a lateral shifting of the output energy substantially without any change in direction. The energy passes through a focussing lens to the detector. As a result, the lateral shifting of the energy output by the anamorphic system does not affect the position of the image on the detector. This compensates for the effect of variations in refractive index of the materials of which the prisms are made, as a function of wavelength and/or temperature.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.