Hoechst Aktiengesellschaft

Hoechst Research & Technology Deutschland Gmbh & Co. Kg

Aventis Research & Technology Deutschland Gmbh & Co.kg

Hoescht Research & Technology Deutchland Gmbh & Co.

Ayako Takeichi

Rainer Wingen

Barbara Hornung

Toshiaki Nonaka

Gerhard Illian

Kazuya Nagao

Wolfgang Schmidt

Javier Manero

Hidemasa Yamaguchi

Thoshiaki Nonaka

Ingrid Muller

Hubert Schlosser

Hans-Rolf D&uuml;bal

Ji Li

Li Ji

Hidenori Fujiwara

Kei Li

Ferroelectric liquid-crystal display having a broad operating temperature range. A ferroelectric liquid-crystal display containing a ferroelectric liquid-crystal mixture which is addressed with voltage pulses&gE;0.9 ms. The display according to the invention is particularly suitable for applications in which the length of the response time is not critical. Such displays can be operated with the same voltage over a broad temperature range; adjustment of the voltage as a function of temperature is not necessary. Examples of preferred applications are displays in chip cards, electronic price and display signs (shelf labels), PDAs (personal digital assistants) and pagers.

Ferroelectric liquid-crystal display with wide range of working temperatures

A ferroelectric liquid crystal mixture having a negative value of &Dgr;e and allowing a high speed response and a low voltage driving, as well as a liquid crystal display devise using the crystal mixture of the invention. The ferroelectric liquid crystal mixture according to the invention comprises two or more compounds from at least two different of the following classes of compounds: A. thiadiazoles, B. phenanthrenes, C. 2-fluoropyridines, D. difluorobenzenes, E. meta-substituted aromatic compounds.

Ferroelectric liquid crystal mixture

Difluorophenyl pyrimidyl pyridine derivatives and the use thereof in

An improved method for achieving a defect-free and uniform liquid crystal alignment in a process for the production of a ferroelectric liquid crystal display device. A process for producing a ferroelectric liquid crystal display device containing a ferroelectric liquid crystal showing at least an N* phase and an SmC* phase and an organic polymer film or an oblique vapor-deposition film of an inorganic substance serving as an alignment layer is provided by aligning the liquid crystal by cooling the liquid crystal once to a temperature region of a phase which resides in the lower temperature region than the N* phase, and then heating it to a temperature region of an N* phase, or by aligning the liquid crystal by applying an electric field in the N* phase.

Process for producing ferroelectric liquid crystal device

Compounds for use in liquid-crystal composition

Disclosed and claimed is a liquid crystal mixture, a liquid crystal device and a display device using the liquid crystal mixture. The liquid crystal display device according to the present invention has improved contrast due to the specific temperature of the liquid crystal mixture. More specifically, the liquid crystal mixture has a temperature range generating a chiral smectic C phase and a temperature range generating a smectic A phase, and having a difference between the cone angle at (T.sub.C/A -10).degree. C. and the cone angle at (T.sub.C/A -40).degree. C. in the temperature range generating the chiral smectic C phase of from zero (0) degree to ten (10) degrees.

Liquid crystal mixture

A ferroelectric liquid crystal mixture which does not lower the conventional transition temperature to the ferroelectric phase (60.degree. C. or above), which maintains the Sa phase within a suitable temperature range, and which is useful for reducing the cone angle is disclosed. The ferroelectric liquid crystal mixture contains at least one of the compounds represented by the following general formulae 1 to 3, and exhibits a Sa/Sc phase transition temperature of 60.degree. C. or more and a cone angle of 47 degree or less atsome temperature between 15.degree. C. and 35.degree. C.: ##STR1##

A ferroelectric liquid crystal mixture which does not lower the conventional transition temperature to the ferroelectric phase (60.degree. C. or above), which maintains the Sa phase within a suitable temperature range, and which is useful for reducing the cone angle is disclosed. The ferroelectric liquid crystal mixture contains at least one of the compounds represented by the following general formula 1 to 3, and exhibits a Sa/Sc phase transition temperature of 60.degree. C. or more and a cone angle of 47 degree or less atsome temperature between 15.degree. C. and 35.degree. C.: ##STR1##

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Tokorozawa, Japan

Ayako Takeichi