Patent · US Expired

Flexoelectric liquid crystal device

US4917475A · kind A · utility

20Cited by
5References
9Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 6, 1987
Grant dateApr 17, 1990
Priority date
Expiry dateMar 6, 2007

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG02F1/1393
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

A liquid crystal device includes a liquid crystal material (30) in which the molecules (15) form a helix having its axis essentially parallel to the plates (13, 20) of the device. A suitable electric field (E), applied essentially perpendicular to the plates, causes planes of the directors (n) to rotate about the field direction to an acute angle .phi. with respect to the helix axis, thereby inducing alternating bands of splay and bend in the material. Such configurations, which have polar symmetry, give rise to the flexoelectric effect in which the polarization (P) of the molecules tends to be parallel to the applied field, and the magnitude of the field is linearly related to tan .phi.. The ability to rotate the directors means that the optical properties of the material can be changed.

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