Surface light source device and liquid crystal display
US6309080A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Mar 27, 1996 |
| Grant date | Oct 30, 2001 |
| Priority date | — |
| Expiry date | Mar 27, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F1/133615
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A surface light source device has a narrowed visual field and increased brightness. The surface light source device can be applied to a liquid crystal display. The back side of a fluorescent lamp is covered with silver foil. Light emitted from the lamp enters a wedge-shaped light guide plate through its incident surface. The light guide plate is designed so that directional light exits from the guide plate. When the light is guided toward a thin-walled end surface through the light guide plate, the light is scattered, reflected, and undergoes other action. Collimated light flux gradually exits from the exiting surface. The light flux passes through two prism sheets successively. As a result, the direction of propagation of the light is restricted in two dimensions. The light flux of increased brightness is directed to the liquid crystal panel. V-shaped channels formed in the prism faces of the two prism sheets PS1, PS2 are arrayed in two mutually perpendicular directions while facing outward. The prismatic vertical angles of the two sheets PS1, PS2 have various desirable combinations of values. For example, where the first sheet PS1 is disposed vertical to the lamp, the vertical an…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.