Patent · US Expired

LCD system having improved contrast ratio

US5124818A · kind A · utility

78Cited by
12References
19Claims
0Family size

Assignee

Inventors

Key dates

Filing dateAug 24, 1990
Grant dateJun 23, 1992
Priority date
Expiry dateAug 24, 2010

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06F2200/1612
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

An LCD display system is formed by stacking two or more independently operated LCD elements. By exploiting the birefringent effect of STN nematic liquid crystals a full range of colors may be displayed. Display rows in the stacked panels are preferably interlaced to achieve high display resolution. Optics are desirably included to collimate light, illuminating the stacked elements, to reduce parallax effects and to disperse light exiting the stacked elements to permit wide angle viewing. The contrast between a pixel in the dark state and in the white state of the high resolution display system may be increased by modifying the .DELTA.nd product of the liquid crystal in the passive regions to compensate for the natural birefringence of the liquid crystal in optically aligned active regions.

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