Spread illuminating apparatus
US6631998B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 31, 2001 |
| Grant date | Oct 14, 2003 |
| Priority date | — |
| Expiry date | Aug 31, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/0068
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A spread illuminating apparatus provides a uniform illuminance, an accurate illumination, an improved visibility, and an expanded screen size. Light sources (5a, 5b) comprising bar-like light conductive members (3a, 3b) and spot-like light sources (4a, 4b), respectively, are disposed close to end surfaces (8a, 8b) of a transparent substrate (2). A light reflection pattern (29) is formed on a surface of the transparent substrate (2) along the length of the light conductive members (3a, 3b). The light reflection pattern (29) comprises grooves (27) and flat portions (28) adjacent to the grooves. The grooves (27) are shaped trapezoidal in section, and the depth thereof increases in proportion to the increase in distance from the light sources (5a, 5b) and measures maximum at the center of the transparent substrate (2).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.