The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 23, 1996
Filed:
Feb. 07, 1992
Michael D Wand, Boulder, CO (US);
Claus Escher, Muehltal, DE;
Mark A Handschy, Boulder, CO (US);
Rohini T Vohra, Boulder, CO (US);
Displaytech, Inc., Boulder, CO (US);
Hoechst Aktiengesellschaft, Frankfurt, DE;
Abstract
Fast response, high contrast Ferroelectric Liquid Crystal (FLC) electro-optic devices in which the FLC retains a helical director structure stable to unwinding are provided. In particular, high contrast distorted helix FLC electro-optic devices including half-wave plates in the visible wavelength region are provided. The FLC cells of this invention incorporate chiral FLCs which exhibit a ferroelectric phase and a chiral nematic phase at temperatures above the ferroelectric phase. The natural helix pitch of the FLC in the ferroelectric phase is sufficiently tighter than the thickness of the FLC layer such that it is not surface-stabilized. The chiral nematic phase has a natural helix pitch sufficiently greater than the cell thickness to facilitate alignment of the FLC in the device to achieve high contrast.