Dual liquid-crystal cell-based visible-to-infrared dynamic image converter
US4679910A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 20, 1985 |
| Grant date | Jul 14, 1987 |
| Priority date | — |
| Expiry date | Mar 20, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F1/133536
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A visible to infrared dynamic image converter light valve includes two liquid crystal layers disposed on opposite sides of a photoconductive substrate. The two liquid crystal layers spatially modulate an incident infrared beam by polarization rotation. A voltage is applied across the two liquid crystal layers, with the layers being responsive to the applied voltage, to vary the polarization rotation. The photoconductive layer receives and absorbs a visible wavelength image and spatially modulates the voltage across the two liquid crystal layers responsively to image intensity spatially to vary the polarization rotation. A mirror reflects the incident infrared beam back through the first and second layers such that the beam passes through the liquid crystal layers twice and is polarization rotated in proportion to the visible wavelength image. A wire grid polarizer converts the polarization rotation of the infrared beam to output intensity modulation to produce an infrared image.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.