Patent · US Expired

Bidirectional dichroic circular polarizer and reflection/transmission type liquid-crystal display device

US6147734A · kind A · utility

26Cited by
4References
19Claims
0Family size

Assignee

Inventor

Key dates

Filing dateDec 16, 1999
Grant dateNov 14, 2000
Priority date
Expiry dateDec 16, 2019

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG02F2203/02
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

In a combination reflective/transmissive liquid-crystal display device, when the liquid-crystal display device is in the transmissive mode, unpolarized light from a light source passes through a circular polarization separating layer, a half-wavelength layer in the off condition, and a first bidirectional dichroic circular polarizing layer and then strikes a liquid-crystal cell, the retardation value of which, as a result of an electrical field applied thereto, changes so as to shift light 0 to .pi., thereby modulating incident circularly polarized light, which is caused to strike a second bidirectional dichroic circular polarizing layer, the transmitted component in which serves as the display light. In the reflective mode, external light passes through the second bidirectional dichroic circular polarizing layer, the liquid-crystal cell, the half-wavelength layer which has been turned on, and the first bidirectional dichroic circular polarizing layer, and is then reflected by the circular polarization separating layer so as to become circularly polarized light that also serves as the display light.

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