Patent · US Expired

Surface light source device, diffusion plate and liquid crystal display device

US7121709B2 · kind B2 · utility

30Cited by
0References
4Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJan 10, 2003
Grant dateOct 17, 2006
Priority date
Expiry dateMay 15, 2023

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG02F1/133615
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

A point-light-source type light emitting portion faces a light incident face located at a corner portion of a light guide plate. A light diffusion pattern for emitting the light in the light guide plate from a light emission face is on the lower surface of the light guide plate. A diffusion prism sheet is on the light emission face. A prism sheet including prisms each having a concentric shape with the light emitting portion at the center is on the lower surface of the diffusion prism sheet, and an uneven diffusion plate is on the upper surface of the diffusion prism sheet. Light emitted from the light emission face of the light guide plate along the light emission face is deflected in the direction perpendicular to the light guide plate by the prism sheet, and the angle of beam spread of the light is spread by the uneven diffusion plate.

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