Liquid crystal switching elements having a parallel electric field and .beta..sub.o which is not 0.degree. or 90.degree.

US5576867A · kind A · utility

Assignee

• Merck Patent GmbH · DE

Inventors

• Gunter Baur · Glückstadt, DE
• Waltraud Fehrenbach · Hersbruck, DE
• Barbara Weber nee Staudacher · Goldbach, DE
• Friedrich Windscheid · Schallstadt, DE
• Rudolf Kiefer · Denzlingen, DE

Key dates

• Filing date: Jun 6, 1995
• Grant date: Nov 19, 1996
• Expiry date: Jun 6, 2015

Classification

• Technology area (CPC G): Physics
• CPC primary: G02F2201/124
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

An electro-optical display device comprising a liquid crystal layer achieves switching using an electric field component which is predominantly parallel to the surface of the liquid crystal layer. Low dependence of image contrast on viewing angle is achieved by selection of parameters including orientation angle .beta..sub.o and pretilt angle .alpha..sub.o of the liquid crystal molecules in the layer. For example, good results are achieved when 0.degree.<.beta..sub.o .ltoreq.20.degree. for liquid crystal molecules having negative dielectric anisotropy and 70.degree..ltoreq..beta..sub.o <90.degree. for molecules having positive dielectric anisotropy. Preferably, 0.degree..ltoreq..alpha..sub.o <30.degree..