Patent · US Expired

Guide plate, surface light source device of side light type and liquid crystal display

US6568819B1 · kind B1 · utility

38Cited by
2References
27Claims
0Family size

Assignees

Inventors

Key dates

Filing dateJul 16, 1999
Grant dateMay 27, 2003
Priority date
Expiry dateJul 16, 2019

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG02B6/0053
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

A guide plate having an emission face for light-output, a back face and an incidence end face for light-input is improved. The emission face is provided with a plurality of projections each of which includes a blunt top portion. The projections have shapes such as like domes or like ridges. Each dome-like projection has a diameter ranging, for example, from 50 &mgr;m to 200 &mgr;m and has a height ranging, for example, from 0.1 &mgr;m to 50 &mgr;m. The dome-like projections distribute with density such that one or more projections are allocated, for example, per box of 0.5 mm×0.5 mm. Ridge-like projections run so as to have a crossing angle, for example, 60 degrees or more with respect to the incidence end face. Ratio of repetition pitch of the ridge-like projections to their height falls within a range, for example, from 5000:1 to 1:1. Height of each ridge-like projection may fall within a range from 1 &mgr;m to 100 &mgr;m. The emission face may be further provided with light scattering pattern consisting of a plurality of scattering elements to scatter illumination light. The improved guide plate is employed in a surface light source device of side light type. The surface l…

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