Electrical addressing of ferroelectric liquid-crystal displays

US5859680A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Dietmar Jungbauer · Weiterstadt, DE
• Heinz Rieger · Hofheim, DE
• Claus Escher · Mühltal, DE
• Gerhard Illian · Frankfurt am Main, DE
• Kazuya Nagao · Saitama, JP
• Mikio Murakami · Kakegawa, JP
• Tsuyoshi Uemura · Osaka, JP
• Hiroyuki Ohnishi · Saitama, JP
• Shozo Fujiwara · Ibaraki, JP

Key dates

• Filing date: May 1, 1995
• Grant date: Jan 12, 1999
• Expiry date: May 1, 2015

Classification

• Technology area (CPC G): Physics
• CPC primary: G09G2320/041
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A process for the stabilization of the spatial alignment of the smectic layers in an FLC switching and/or display element, in which the original position of the smectic layers has been modified by electrical field treatment, which comprises alternately switching the elements during non-operation and/or when a certain temperature is exceeded which is above a predetermined temperature range which includes the operating temperature region and/or when the temperature falls below a certain temperature which is below a predetermined temperature range which includes the operating temperature region. Use of the process according to the invention ensures long-term functioning of the switching and display device, even in the case of repeated regeneration of the quasi-bookshelf geometry, and prevents worsening in the contrast and brightness and the occurrence of ghost images.