Light control plate, surface light source device and transmissive image display device
US7753544B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 26, 2008 |
| Grant date | Jul 13, 2010 |
| Priority date | — |
| Expiry date | Jan 9, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B27/0961
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A light control plate 30A of the present invention is disposed in front of a surface light source 20 that emits, in a predetermined direction, parallel light Fi having a substantially uniform luminance distribution. The light control plate 30A has a light incidence surface 30a, at which there are provided optical path control sections 31A of concave and/or convex cross-sectional shape, and a planar light exit surface 30b. The surface of the optical path control sections 31A comprises first to M-th planar portions 32A1 to 32AM. The inclination angles α1 to αM and pitch ratios L1 to LM of each planer portion are specified in such a manner that the parallel light Fi can be spread within an exit angle range −θmax to θmax relative to the predetermined direction, to exit as light having a substantially uniform luminance angular distribution within the exit angle range. Thereby, parallel light having a uniform luminance distribution can be spread within a predetermined angle range, to exit as light having a substantially uniform luminance angular distribution within the angle range.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.