Fluorescent lamp providing uniform backlight illumination for displays
US6979101B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 7, 2004 |
| Grant date | Dec 27, 2005 |
| Priority date | — |
| Expiry date | Jul 7, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J61/307
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A bent fluorescent lamp for backlighting a display providing uniform illumination. A fluorescent lamp is made from a tubular glass envelope having right angles formed therein. The right angles provide improved illumination of a plane surface for backlighting a liquid crystal display. The right angles eliminate dark regions in the illuminated surface. A right-angled bend is also formed at the ends of the fluorescent lamp. An electrode is positioned sufficiently far from a central portion of the lamp so that any dark spaces in the gas discharge of the fluorescent lamp, such as the Faraday dark space associated with a cathode of a lamp are not formed within the central portion. As a result, the central portion of the fluorescent lamp has a uniform brightness or intensity providing improved illumination for backlighting a liquid crystal display. The resulting more uniform illumination with less dark regions results in a more legible display and more accurate information being displayed. A method of forming a right-angled bend in a glass tube is also disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.