Spread illuminating apparatus without light conductive bar
US6761461B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 15, 2002 |
| Grant date | Jul 13, 2004 |
| Priority date | — |
| Expiry date | Jan 21, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/0068
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A spread illuminating apparatus includes a light conductive plate provided with a light entry face at its corner, having a spot-like light source disposed close to or in contact with the light entry face, and having a light reflection pattern formed on its major surface. The light reflection pattern comprises a plurality of arced grooves and is configured such that the grooves have their depths increasing with an increase in the distance from the light source, and that each of the grooves has its depth increasing with an increase in the light emission angle made by a line of a light emission direction with respect to a diagonal line from the light source. Thus, the light reflection pattern is adapted to reflect more light at an area farther from the light source and the diagonal line as well, thereby further improving uniformity in brightness all over the light conductive plate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.