Surface light source device of side-light type
US6049649A · kind A · utility
Assignees
Inventor
Key dates
| Filing date | Mar 25, 1997 |
| Grant date | Apr 11, 2000 |
| Priority date | — |
| Expiry date | Mar 25, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/0055
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A surface light source device of side-light type enables concentrated output of illumination light to a frontal direction. A flux having clear directivity is outputted from window portions 1w on an emitting surface 5 of a light guide plate 1 with emitting directivity. This flux is represented by a beam C01 outputted in a direction at an angle of 70.degree.. A flux C02 incident on reflection portions 1r is returned to the light guide plate 1 and is given an opportunity of output from the window portions 1w again. The flux C01 having escaped from the window portions 1w to an air layer AR is obliquely incident on flat regions 14g of a propagation direction characteristics modifier 14, and a degree of parallelization of the flux in a propagation direction is improved. The flux is blocked by the reflection portions 1r from being incident on a notch portion (uneffective area) between the flat regions 14g. After total reflection by a total reflection surface 14b of each projection element 14c, the flux is outputted from a flat outside surface 14h to a frontal direction without degrading the improved degree of parallelization. The projection elements 14c may be two-dimensionally arrayed. A…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.