Backlighting for electro-optical passive displays and transflective layer useful therewith
US4832459A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 27, 1987 |
| Grant date | May 23, 1989 |
| Priority date | — |
| Expiry date | May 27, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B33/28
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
In an electroluminescent lamp having a phosphor layer disposed between corresponding lamp electrodes adapted to apply an excitation potential to cause the phosphor layer to emit light, a front lamp electrode which, in addition to being light transmissive to radiation from the phosphor layer, consists of a thin layer of light-transmissive binder containing a distribution of discrete particles that are characteristically light-reflective and electrically conductive. The electrode particles provide aggregate diffuse outward reflectance sufficient to serve as a reflector behind an LCD display for ambient light that falls upon the LCD display to illuminate the display under light ambient conditions. Furthermore, the particles in the electrode layer are adapted to contribute to electrical continuity through the layer sufficient to apply excitation to the phosphor layer, and the electrode layer particles have sufficient spaces between them to provide escape-paths for light from the excited phosphor layer to back-illuminate the LCD display under dark ambient conditions. A method of forming the improved electrode, e.g. by shear transfer techniques, is also described. Certain aspects of the …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.