Abstract: A liquid crystal device, comprising: a pair of substrates, and a ferroelectric liquid crystal disposed between the substrates, each of the substrates having thereon an electrode for applying a voltage to the liquid crystal and a uniaxial alignment film provided with a uniaxial alignment axis, the alignment films on the pair of substrates being substantially parallel with each other and having an identical axis direction; wherein the ferroelectric liquid crystal is disposed in such an alignment state that the liquid crystal shows a pretilt angle .alpha., a cone angle H, an inclination angle .delta. of SmC* layer, and an apparent tilt angle .theta. a satisfying relationships of: H<.alpha.+.delta. and H>.theta.

Abstract: A liquid crystal composition comprises at least one type of liquid crystal compound having the following general formula (I) and at least one type of liquid crystal compound having the following general formula (II): ##STR1## wherein R.sub.1 and R.sub.2 each is a straight-chain or branched-chain alkyl group having 1 to 18 carbon atoms. These alkyl groups may have alkoxy groups having 1 to 12 carbon atoms as substituents. Both R.sub.1 and R.sub.2 are optically inactive. Z.sub.1 is a single bond, --O--, ##STR2## wherein R.sub.3 and R.sub.4 each is a straight-chain or branched-chain alkyl group having 1 to 18 carbon atoms. Z.sub.2 and Z.sub.3 each is single bond, ##STR3## A.sub.1 is --A.sub.2 -- or --A.sub.2 --A.sub.3 --, wherein A.sub.2 and A.sub.

Abstract: A ferroelectric chiral smectic liquid crystal composition, comprising at least one compound represented by the following formula (I): ##STR1## wherein R.sub.1 denotes a linear or branched alkyl group having 1-18 carbon atoms capable of having a substituent, R.sub.2 denotes a linear or branched alkyl group having 1-14 carbon atoms capable of having a substituent; X.sub.1 and X.sub.2 respectively denote a single bond, --O--, ##STR2## m is 0-7; and n is 0 or 1; and at least one compound represented by the following formula (II): ##STR3## wherein R.sub.3 denotes a linear or branched alkyl group having 1-18 carbon atoms capable of having a substituent; R.sub.4 denotes a linear alkyl group having 1-10 carbon atoms; X.sub.3 denotes a single bond, --O--, ##STR4## Y denotes ##STR5## --CH.sub.2 O-- or --OCH.sub.

Abstract: A ferroelectric chiral smectic liquid crystal composition, comprising at least one optically active compound represented by the following formula (I): ##STR1## wherein R.sub.1 and R.sub.2 respectively denote a linear or branched alkyl group having 1-18 carbon atoms capable of having a substituent, at least one of R.sub.1 and R.sub.2 being optically active; X.sub.1 denotes --O--, ##STR2## and X.sub.2 denotes a single bond, --O--, ##STR3## and at least one compound represented by the following formula (II): ##STR4## wherein R.sub.3 and R.sub.4 respectively denote a linear or branched optically inactive alkyl group having 1-18 carbon atoms capable of having an alkoxy group of 1-12 carbon atoms; X.sub.3 and X.sub.4 respectively denote a single bond, --O--, ##STR5## and m and n are respectively 0, 1 or 2 with proviso that both of m and n are not 0.

Abstract: A liquid crystal composition having a chiral smectic phase comprising at least one liquid crystal compound having the general formula (I) shown below: ##STR1## wherein R.sub.1 and R.sub.2 each is a straight chain or branch alkyl group which may have a substituent group having 1 to 16 carbons, Z.sub.1 is a single bond, --O--, ##STR2## and X.sub.1 is a halogen atom.

Abstract: A ferroelectric chiral smectic liquid crystal composition, comprising at least one compound represented by the following formula (I): ##STR1## wherein R.sub.1 and R.sub.2 respectively denote a linear or branched alkyl group having 1-18 carbon atoms capable of having a substituent; X.sub.1 and X.sub.2 respectively denote a single bond, --O--, ##STR2## Y.sub.1 denotes --CH.sub.2 O-- or --OCH.sub.2 --; and m and n are respectively 1 or 2; and at least one compound represented by the following formula (II): ##STR3## wherein R.sub.3 denotes a linear or branched alkyl group having 1-18 carbon atoms capable of having a substituent; X.sub.3 denotes a single bond, --O-- or ##STR4## Z denotes a single bond or ##STR5## and p is an integer of 1-12.

Abstract: A ferroelectric chiral smectic liquid crystal composition, comprising at least one compound represented by the following formula (I): ##STR1## wherein R.sub.1 and R.sub.2 respectively denote a linear or branched alkyl group having 1-18 carbon atoms capable of having a substituent, at least one of R.sub.1 and R.sub.2 being optically active; and X.sub.1 denotes a single bond, --O--, ##STR2## and at least one compound represented by the following formula (II): ##STR3## wherein R.sub.3 and R.sub.4 respectively denote a linear or branched alkyl group having 1-18 carbon atoms capable of having a substituent; X.sub.2 and X.sub.3 respectively denote a single bond, --O--, ##STR4## and m and n are respectively 0, 1 or 2 with proviso that m+n=2 or more.

Abstract: A liquid crystal composition, comprising: at least one optically active mesomorphic compound having an asymmetric carbon atom to which a fluorine atom is directly bonded.

Abstract: A liquid crystal device with a decreased temperature-dependence of response speed is obtained by using a liquid crystal composition having a temperature range where the composition assumes chiral smectic C phase. The temperature range of chiral smectic C phase includes a) a first temperature range where the liquid crystal composition shows a cone angle in chiral smectic C phase which increases on temperature decrease down to a mediate temperature, and b) a second temperature range, below the first temperature range, where the liquid crystal composition shows a cone angle in chiral smectic C phase which decreases on further temperature decrease below the mediate temperature.

Abstract: A ferroelectric chiral smectic liquid crystal composition, comprising: at least one optically active compound represented by the following formula (II): ##STR1## wherein R.sub.3 denotes a linear or branched alkyl group having 1-18 carbon atoms capable of having a substituent; X.sub.3 denotes a single bond, ##STR2## Z.sub.1 denotes a single bond or ##STR3## and m is 1-12; at least one compound represented by the following formula (III): ##STR4## wherein R.sub.4 and R.sub.5 respectively denote a linear or branched alkyl group having 1-18 carbon atoms capable of having a substituent, at lease one of R.sub.4 and R.sub.5 being optically active; X.sub.4 denotes a single bond, ##STR5## and X.sub.5 denotes a single bond, ##STR6## and at least one compound represented by the following formula (I) or (IV): ##STR7## wherein R.sub.1 and R.sub.2 respectively denote a linear or branched alkyl group having 1-18 carbon atoms capable of having a substituent of C.sub.1 -C.sub.12 alkoxy group; X.sub.1 and X.sub.

Abstract: A liquid crystal composition comprising at least one mesomorphic compound represented by the following formula (I): ##STR1## wherein R.sub.1 and R.sub.2 respectively denote a linear or branched alkyl group having 1-16 carbon atoms optionally substituted; Z.sub.1 denotes a single bond, --O--, --COO-- or --OCO--; X.sub.1 denotes halogen; and A.sub.1 denotes a single bond or ##STR2## and at least one mesomorphic compound represented by the following formula (II): ##STR3## wherein R.sub.3 and R.sub.4 respectively denote an alkyl group having 2-16 carbon atoms optionally substituted; Y.sub.1 denotes a single bond, ##STR4## Z.sub.2 and Z.sub.3 respectively denote a single bond, --O--, ##STR5## A.sub.2 and A.sub.3 respectively denote a single bond, ##STR6## X.sub.2 and X.sub.3 respectively denote hydrogen, F, Cl, Br, --CH.sub.3, --CN or --CF.sub.3 ; and k is 0 or 1 with the proviso that Z.sub.2 is a single bond when A.sub.2 is a single bond, and Z.sub.3 is a single bond when A.sub.3 is a single bond and k is 0.

Abstract: A liquid crystal composition, comprising: at least one mesomorphic compound represented by the following formula (I): ##STR1## and at least one mesomorphic compound represented by the following formula (II):R.sup.3 --X.sup.3 --A.sup.2 --B--A.sup.3 --X.sup.4 --R.sup.4(II),The liquid crystal composition is easily aligned by a simple rubbing method to provide a uniform monodomain and further provides wider driving voltage and temperature margins effective for providing a practical ferroelectric liquid crystal device.

Abstract: A liquid crystal composition, comprising: at least one mesomorphic compound represented by the following formula (I):R.sup.1 --X.sup.1 --A.sup.1 --B--A.sup.2 --X.sup.2 --R.sup.2(I)and at least one mesomorphic compound represented by the following formula (II): ##STR1## The liquid crystal composition is easily aligned by a simple rubbing method to provide a uniform monodomain and further provides wider driving voltage and temperature margins effective for providing a practical ferroelectric liquid crystal device.

Abstract: A liquid crystal composition, comprising: at least one mesomorphic compound represented by the following formula (I): ##STR1## wherein R.sup.1 and R.sup.2 independently denote a linear or branched alkyl group having 1-18 carbon atoms capable of including one or non-neighboring two or more methylene groups which can be replaced with at least one species of --O--, --CO--, --COO--, --OCO--, --OCOO-- or --CH(X)-- with the proviso that --O-- cannot directly be connected to --O-- and X denotes halogen; Z.sup.1 denotes --COO-- or --CH.sub.2 O--; X.sup.1 and X.sup.2 independently denote a single bond, --O--, --COO--, --OCO--, --CO-- or --OCOO--; A.sup.1 denotes a single bond, ##STR2## Y.sup.1 and Y.sup.2 independently denote hydrogen, halogen, --CH.sub.3 -- or CF.sub.3 --; and at least one mesomorphic compound represented by the following formula (II): ##STR3## wherein R.sup.3 and R.sup.

Abstract: A ferroelectric chiral smectic liquid crystal composition, comprising at least one compound represented by the following formula (I): ##STR1## wherein R.sub.1 and R.sub.2 respectively denote a linear or branched alkyl group having 1-8 carbon atoms capable of having a substituent; X.sub.1 and X.sub.2 respectively denote a single bond, ##STR2## Y.sub.1 denotes --CH.sub.2 O-- or --OCH.sub.2 --; and m and n are respectively 1 or 2; and at least one compound represented by the following formula (II): ##STR3## wherein R.sub.3 denotes a linear or branched alkyl group having 1-18 carbon atoms capable of having a substituent, R.sub.4 denotes a linear alkyl group having 1-10 carbon atoms; X.sub.3 denotes a single bond, ##STR4## Y.sub.

Abstract: A mesomorphic compound represented by the following formula (I): ##STR1## wherein R.sub.1 and R.sub.2 respectively denote a linear or branched alkyl group having 1-16 carbon atoms capable of having a substituent; Y.sub.1 denotes --COO--, --OCO--, --CH.sub.2 --or --OCH.sub.2 --; Z.sub.1 denotes a single bond, --O--, --COO--, --OCO-- or --OCOO--; and X denotes a halogen, cyano group or methyl group.

Abstract: A ferroelectric chiral smectic liquid crystal composition, comprising at least one compound represented by the following formula (I): ##STR1## wherein R.sub.1 denotes a linear or branched alkyl group having 1-18 carbon atoms capable of having a substituent; R.sub.2 denotes a linear or branched alkyl group having 1-14 carbon atoms capable of having a substituent; X.sub.1 and X.sub.2 respectively denote a single bond, --O--, ##STR2## m is 0-7; and n is 0 or 1; and at least one compound represented by the following formula (II): ##STR3## wherein R.sub.3 and R.sub.4 respectively denote a linear alkyl group having 1-18 carbon atoms and one --CH.sub.2 -- not bonded to X.sub.4 in the alkyl group can be replaced with --O--; X.sub.3 and X.sub.4 respectively denote a single bond, --O--, ##STR4## and p and q are respectively 0, 1 or 2 with proviso that both of p and q are not 0.

Abstract: A ferroelectric chiral smectic liquid crystal composition, comprising at least one compound represented by the following formula (I): ##STR1## wherein R.sub.1 denotes a linear or branched alkyl group having 1-18 carbon atoms capable of having a substituent; X.sub.1 denotes a single bond, --O-- or ##STR2## Z denotes a single bond or ##STR3## denotes ##STR4## and n is an integer of 1-12; and at least one compound represented by the following formula (II): ##STR5## wherein R.sub.2 and R.sub.3 respectively denote a linear or branched alkyl group having 1-18 carbon atoms capable of having a substituent, at lease one of R.sub.2 and R.sub.3 being optically active; X.sub.2 and X.sub.

Abstract: A ferroelectric chiral smectic liquid crystal composition, comprising at least one optically active compound represented by the following formula (I): ##STR1## wherein R.sub.1 denotes a linear alkyl group having 1-14 carbon atoms; R.sub.2 denotes a linear or branched alkyl group having 1-14 carbon atoms capable of having a subtituent; and X.sub.1 denotes a single bond, ##STR2## and at least one compound represented by the following formula (II): ##STR3## wherein R.sub.3 denotes a linear or branched alkyl group having 1-18 carbon atoms capable of having a substituent; R.sub.4 denotes a linear alkyl group having 1-10 carbon atoms; X.sub.

Abstract: A ferroelectric chiral smectic liquid crystal composition, comprising at least one compound represented by the following formula (I): ##STR1## wherein, R.sub.1 denotes a linear or branched alkyl group having 1-18 carbon atoms capable of having a substituent; R.sub.2 denotes a linear alkyl group having 1-12 carbon atoms; X.sub.1 denote a single bond, --O--, ##STR2## respectively denote ##STR3## and at least one compound represented by the following formula (II): ##STR4## wherein R.sub.3 and R.sub.4 respectively denote a linear or branched alkyl group having 1-18 carbon atoms capable of having a substituent; X.sub.2 and X.sub.3 respectively denote a single bond, --O--, ##STR5## and m and n are respectively 0, 1 or 2 with proviso that m+n is 2 or above.