Patent · US Expired

Electro-optic display devices and methods

US4009934A · kind A · utility

62Cited by
2References
11Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJun 28, 1974
Grant dateMar 1, 1977
Priority date
Expiry dateJun 28, 1994

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG02F1/1392
  • WIPO fieldBasic materials chemistry
  • WIPO sectorChemistry

Abstract

An electro-optic display is provided which uses a liquid crystalline composition (a) having a positive, zero frequency dielectric anisotropy and (b) exhibiting a dielectric anisotropy inversion with increasing frequency of an applied field. Such a composition is subjected to an electric field of a first audio frequency and then subjected to a field of a second audio frequency of a magnitude sufficient to produce a dielectric anisotropy inversion in said composition. The resultant anisotropy changes allow the molecular orientation of the composition to be altered by the applied field thereby changing the optical properties of the composition.

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