Patent · US Expired

Liquid crystal display device with a phase plate for shadow compensation

US5119220A · kind A · utility

126Cited by
16References
16Claims
0Family size

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Key dates

Filing dateJun 26, 1989
Grant dateJun 2, 1992
Priority date
Expiry dateJun 26, 2009

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG02F2413/01
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

A field effect type liquid crytal display device suitable for use in a high level multiplexing drive, has liquid crystal molecules twisted with an angle from 180.degree. to 350.degree. which are held between two polarizers. The liquid crystal display device generates an interference color due to a birefringent effect of liquid crystal. The occurrence the of this interference color can be prevented by laminating color compensation plates but if the thickness of the optical system increases, a deviation in a display position or a change in the contrast occurs dependent on the observing direction. A phase compensation for the color interference of the liquid crystal is achieved by setting the retardation of the liquid crystal cells having a large twist angle of the liquid crystal molecules and by laminating thin phase plates. Thus, the display quality is improved and the optical axis of an achromatic display can be easily adjusted.

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