Liquid-crystal image converter device
US4368386A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 3, 1981 |
| Grant date | Jan 11, 1983 |
| Priority date | — |
| Expiry date | Feb 3, 2001 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F1/135
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The invention provides an image converter device which utilizes a liquid crystal cell in which a layer of a nematic material or a nematic-cholesteric mixture is enclosed between a first plate of a photoconductive material, provided with an external electrode, and a second transparent plate, provided with an internal electrode. The photoconductive material may be bismuth oxide, or a mixture of the latter with germanium or silicon oxide. A direct or alternative voltage is applied between the electrodes. An X-rays image, or an image displayed on the screen of a C.R. tube is projected onto the photoconductive plate whose conductivity, thus spatially modulated, causes a spatially variable voltage to be applied in the liquid crystal layer. Various electro-optical effects, such as dynamic scattering, controlled birofringence or controlled rotatory polarization in a twisted structure, can be used to make the projected image to appear in the liquid crystal layer illuminated by a visible light read-out beam and be directly observed or enlarged by projection onto a screen.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.