Patent · US Expired

Surface light source device

US5961197A · kind A · utility

20Cited by
7References
3Claims
0Family size

Assignees

Inventors

Key dates

Filing dateDec 9, 1996
Grant dateOct 5, 1999
Priority date
Expiry dateDec 9, 2016

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG02B6/0061
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

A wedge-shaped light scattering guide plate 10 employed in a surface light source device of side-light type has a width equal to the length of a primary light source element. An incidence end surface 11 is formed as a matte surface (rough surface) by a matting process. The incidence end surface 11 is provided with roughness which is uniform or increases toward end portions. The roughened incidence end surface 11 produces scattered light in the vicinity of the incidence end surface, especially at both side end portions. The scattered light contributes to elimination of variation in luminance which tends to occur in the vicinity of the incidence end surface 11. A light diffusing plate may be interposed between the primary light source element and the light scattering guide plate.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.