Patent · US Expired

Display device for displaying light images on a dark background

US4405210A · kind A · utility

6Cited by

9References

4Claims

0Family size

Assignee

Siemens Aktiengesellschaft · DE

Inventors

Guenter Baur · Glückstadt, DE
Waldemar Greubel · Munich, DE
Hans Krueger · Munich, DE
Alois Schauer · Kleinmachnow, DE

Key dates

Filing date	May 19, 1980
Grant date	Sep 20, 1983
Priority date	—
Expiry date	May 19, 2000

Classification

Technology area (CPC G)Physics
CPC primaryG02F1/13725
WIPO fieldOptics
WIPO sectorInstruments

Abstract

A display device for displaying bright images on a dark background, which device includes a liquid crystal cell having a liquid crystal layer with switchable zones between at least two optical states, a light trap in the form of a body exhibiting fluorescent particles and having light emergent windows disposed behind each of the switchable zones in the direction of observation, characterized with the liquid crystal layer containing at least one pleochroic dye. The dye in the liquid crystal layer acting by itself or in conjunction with a polarizer can block passage of the fluorescent light during one optical state of the layer and enable passage of the light during the other state.

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