Scanning back illuminating light source for liquid crystal and other displays
US5387921A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 26, 1993 |
| Grant date | Feb 7, 1995 |
| Priority date | — |
| Expiry date | Apr 26, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F1/133622
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A scanning flat back light source for use with light valve devices such as liquid crystal displays. It is formed by an array of parallel fluorescent tubes with fluorescent layers therein. One end of each tube is provided with an electrode and the other end connected together through a transverse chamber to form a single vacuum unit. When electrical potential is applied across electrodes in two different chambers, the two chambers and the portion of the transverse chamber connecting the two chambers form a fluorescent lamp where gas discharge produces ultraviolet light that causes a fluorescent layer on the inside walls of the tubes to produce single-color or multi-color light. During successive time intervals in the scanning operation, at least one of the tubes which are caused to emit light during one time interval is also causes to emit light during a subsequent time interval so that the charged particles present in such overlapping tube accelerate the gas discharge process during the subsequent time interval. This device is particularly suitable for portable devices such as portable computers and has high brightness and efficiency without excessive power consumption.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.