Abstract: The present invention provides a liquid crystal light modulation device which has a cell comprising a pair of substrates at least one of which is transparent and which have electrodes and are opposed through a spacer, a ferroelectric liquid crystal layer which is enclosed in said cell and which has a phase series where a nematic phase (N*phase) or an isotropic phase (I phase) is shown on a just higher temperature side of a ferroelectric phase (smectic C* phase, Sc* phase) and two polarizing plates which sandwich the cell therebetween, liquid crystal molecules at one interface between the liquid crystal layer and the substrate being fixed to the substrate more weakly than liquid crystal molecules at the other interface between the liquid crystal and the substrate wherein the liquid crystal molecule weakly fixed is fixed to such an extent that inversion of spontaneous polarization of the liquid crystal molecule occurs upon application of an electrical field to the liquid crystal layer through the electrodes, or

Abstract: A ferroelectric liquid crystal device which comprises at least one pair of counterposed substrates, a ferroelectric liquid crystal material provided between the substrates, means for applying an electric field to the liquid crystal material and provided at the substrates, an alignment-controlling layer provided on the surface on the liquid crystal material side of each of the substrates, and a sealing member at the peripheral edges of the substrates, the alignment-controlling layer being a film of an organic polymer whose .beta. dispersion temperature is higher than the curing temperature of a sealant for the sealing member, preferably at least 200.degree. C., has a good alignment state of ferroelectric liquid crystal molecules achieved by cooling alone without any application of an electric field and has good display qualities such as a high contrast.

Abstract: A liquid crystal display element comprising a pair of substrates, a pair of electrodes provided on the respective substrates, at least one of which is transparent and a liquid crystal layer disposed between said substrates, the liquid crystal layer comprising a nematic liquid crystal, which exhibits a positive dielectric constant anisotropy and contains an optically active substance, the liquid crystal moleccule orientation direction in the liquid crystal layer is twisted in the range of 200.degree. to 250.degree. from the one substrate surface toward the other substrate surface so as to form a helical structure therein. A polyimide orientation film is provided between the electrodes and the liquid crystal layer. The polyimide orientation film is one made of a polyimide prepared by reacting a diamine compound having a long-chain hydrocarbon group or a diamine compound having a trifluoromethyl group with a tetracarboxylic dianhydride and causes a pretilt angle of at least 3.degree.

Abstract: The element comprises a pair of transparent substrates, a pair of light-transmitting electrodes each provided on the respective substrates, a ferroelectric liquid crystal layer disposed between the pair of substrates and orientation control films for the molecules of the ferroelectric liquid crystal provided between the electrodes and the ferroelectric liquid crystal layer. The orientation control film controls a tile angle of a biphenyle series nematic liquid crystal having biphenyl ring system below 1.5.degree. and causes a uniform molecule orientation characteristic and a memory property for the ferroelectric liquid crystal element of smectic C* liquid crystal and having a liquid crystal layer thickness of even more than 4 .mu.m.

Abstract: In a liquid crystal display device produced by forming an orientation controlling film on each surface of upper and lower substrates having an electrode, placing a liquid crystal composition between said substrates, and then sealing the periphery of the substrate, the response times, particularly those at low temperatures can be reduced by using, as the aforesaid liquid crystal composition, a liquid crystal composition which is obtained by adding a material having a glass transition temperature (T.sub.g) of -90.degree. C. or lower to a liquid crystal material base and has a T.sub.g of -82.degree. C. or lower.

Abstract: A colorless liquid crystalline compound having at least one 6-membered ring and non-cyclic end groups in the molecular skeleton, said 6-membered ring containing two or more carbon atoms, at least one of which is directly bonded to a methylene group of a non-cyclic group having an alkoxy group at another end has a wide mesomorphic range. When said colorless liquid crystalline compound is mixed with a liquid crystal composition, the resulting mixture also has an enlarged mesomorphic range and in almost all cases has a reduced viscosity.

Abstract: A liquid crystal compound of the formula: R.sub.2 --X.sub.1 --Y.sub.1 --C(O)S--Y.sub.2 --Z, wherein R.sub.2 is preferably C.sub.7-14 alkyl; X.sub.1 is --COO-- or --OCO; ##STR1## and Z is --NO.sub.2 or --CN, shows a smectic phase, is large in positive delectric anisotropy and can give a liquid crystal composition suitable for use in a thermal address display device.

Abstract: The present liquid crystal compounds are novel ester-type compounds showing a smectic liquid crystal phase and being capable of increasing a dielectric constant anisotropy, represented by the following general formula: R--X.sub.1 --Y.sub.1 --X.sub.2 --Y.sub.2 --NO.sub.2, wherein R is an alkyl group; X.sub.1 and X.sub.2 are the same or different from each other and are group --COO-- and --OOC--, and when X.sub.1 is group --COO--, ##STR1## The present liquid composition contains the novel compound, and the present liquid crystal display device uses the liquid crystal composition for utilizing the characteristics of the novel compound. Particularly, the present liquid crystal display device is a thermally addressed display device.

Abstract: The liquid crystal compound of this invention is characterized by having the general formula.

Abstract: The present invention is characterized by a smectic liquid crystal compound represented by the following formula: ##STR1## wherein R is selected from alkyl and alkoxy groups; X from ##STR2## m and n are natural numbers; and R* is an optically active group containing an asymmetric carbon atom, and a liquid crystal composition containing said compound as a component. This compound is excellent in optical stability and high-speed response.

Abstract: A colorless liquid crystalline compound having at least one 6-membered ring and non-cyclic end groups in the molecular skelton, said 6-membered containing two or more carbon atoms, at least one of which is directly bonded to a methylene group of a non-cyclic group having an alkoxy group at another end has a wide mesomorphic range. When said colorless liquid crystalline compound is mixed with a liquid crystal composition, the resulting mixture also has an enlarge mesomorphic range and in almost all cases has a reduced viscosity.

Abstract: Phthalonitrile derivatives represented by the formula (I): ##STR1## (wherein X and Y each represents an alkyl group having 1 to 9 carbon atoms, an alkoxy group havng 1 to 9 carbon atoms, ##STR2## (wherein R.sup.1 represents a hydrogen atom, --C.sub.m H.sub.2m+1, --O--(CH.sub.2 CH.sub.2 O).sub.n --C.sub.m H.sub.2m+1, ##STR3## or a halogen atom, wherein m represents an integer of 1 to 9 and n represents 0, 1 or 2), but at least one of X and Y does not represent a methyl group, and Y does not not represent an alkyl group having 1 to 9 carbon atoms or an alkoxy group having 1 to 9 carbon atoms in the case that X represents R.sup.1 H and R.sup.1 represents an alkyl group having 1 to 9 carbon atoms).

Abstract: A liquid crystal display element which may have a multi-layer structure comprising substrates having electrodes and liquid crystal orientation controlling films on the sides thereof facing a liquid crystal layer and one or more liquid crystal layers interposed between said substrates, characterized in that the liquid crystal orientation controlling film is made from a copolymer produced by reacting a dibasic acid dihydrazide, a diamine and a tetracarboxylic acid dianhydride, followed by ring closure and dehydration with heating, is excellent in transparency and the electrode (partially reflected) pattern is hardly observable.