Surface light source device of side light type
US6406158B1 · kind B1 · utility
Assignees
Inventor
Key dates
| Filing date | Aug 10, 1998 |
| Grant date | Jun 18, 2002 |
| Priority date | — |
| Expiry date | Aug 10, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/0061
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Illuminating light, supplied from a primary light source of a surface light source device of side light type, passes through an incidence surface (12A) and enters a wedge-shaped scattering guide plate (12). Inside the guide plate (12), the illuminating light propagates toward the end while being repeatedly reflected between a back face (12B) and an emission surface (12C). During this process, the illuminating light receives scattering action of particles or the like in the guide plate (12). The emission surface (12C) provides a prism surface. The back face (12B) comprises a plurality of projections in a belt region (AR1) along an edge (EL). The projections run generally parallel to the edge (EL) and each has a pair of slopes (12G and 12H). The height of the projections (that is, depth of the troughs) or the inclination of the slopes (12G and 12H) preferably decrease according to distance from the edge (EL). The projections diffuse light propagation direction, thereby preventing generation of bright lines around the edge (EU) of the emission surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.