Supertwist liquid crystal display

US5178790A · kind A · utility

Assignee

• MERCK PATENT GESELLSCHAFT MIT BESHRANK TER HAFTUNG · DE

Inventors

• Georg Weber · Langen (Hessen), DE
• Herbert Plach · Darmstadt, DE
• Volker Reiffenrath · Roßdorf, DE
• Reinhard Hittich · Seeheim-Jugenheim, DE

Key dates

• Filing date: May 15, 1989
• Grant date: Jan 12, 1993
• Expiry date: May 15, 2009

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C09K19/44
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

Supertwist liquid crystal display elements with excellent steepness of the characteristic are obtained, if the nematic liquid crystal mixture satisfies the following conditions: PA1 a nematic phase range of at least 60.degree. C., PA1 a viscosity of 30 mPa.s or lower, and PA1 .DELTA..epsilon./.epsilon..perp.<2.0, where .DELTA..epsilon. is the dielectric anisotropy and .epsilon..perp. is the dielectric constant in the direction of the short axis of the liquid crystal molecules.