Patent · US Expired

Polymer dispersed liquid crystal color projection display apparatus

US5245449A · kind A · utility

37Cited by
20References
15Claims
0Family size

Assignee

Inventors

Key dates

Filing dateAug 30, 1990
Grant dateSep 14, 1993
Priority date
Expiry dateAug 30, 2010

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04N9/3105
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

A liquid crystal color projection display apparatus having a projection light source, a plurality of liquid crystal display elements for separately modulating lights of a plurality of colors from the projection light source and an optical projection system for projecting light to a projection screen, wherein a liquid crystal and polymer composite put between a pair of substrates each equipped with an electrode is used as the liquid crystal display element, in which a liquid crystal material is dispersed and held in a polymer matrix and the refractive index of the polymer matrix substantially agrees with the ordinary light refractive index (n.sub.o) of the liquid crystal material used, a dichroic mirror is used for color splitting or color synthesis and the dependence of dichroic mirror's spectral characteristics upon the state of polarization is decreased. Clear color images of high purity and excellent hue can be obtained. Size and the cost of the liquid crystal display apparatus can be reduced.

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