Abstract: A method for driving an optical modulation device of a group of scanning electrodes and a group of signal electrodes arranged so that picture elements are defined at the intersections therebetween and a bistable optical modulation material assuming one of two stable states between the groups of electrodes, by in a first phase orienting the bistable material at the picture elements on an N-th scanning electrode to one stable state, and applying a writing signal to the signal electrodes in synchronism with a scanning signal to the N-th scanning electrode and while orienting the bistable material at the picture elements on an N+1-th scanning electrode to the one stable state.

Abstract: A chiral smectic liquid crystal composition is formed by including at least one species of a mesomorphic compound represented by the following formula (I): ##STR1## wherein X denotes F, Cl, Br, CF.sub.3, NO.sub.2 or CN; Y denotes a single bond, ##STR2## --CH.sub.2 O-- or --OCH.sub.2 --; and R denotes a linear or branched alkyl group having 1-20 carbon atoms optionally substituted. The composition shows improved switching characteristics and, when used in combination with an alignment film providing a high pre-tilt angle, provides an increased contrast at a large drive margin and with little tendency of monostabilization of a memory state.

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 driving method for an optical modulation device is applicable to driving of an optical modulation device, e.g., a liquid crystal device having a matrix electrode arrangement comprising a group of scanning electrodes, a group of signal electrodes oppositely paced from the group of scanning electrodes, and an optical modulation materials showing bistability with respect to an electric field applied thereto disposed between the groups of scanning electrodes and signal electrodes.

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 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: An optical recording medium comprising a substrate and a thin organic film containing at least one kind of dye selected from polymethine family dyes, perylium family dyes, and cyanine family dyes, and a recording process comprising scanning the optical recording medium with a high intensity light beam such as a laser beam to form optically detectable pits on the recording medium.

Abstract: A method for driving an optical modulation device having a group of scanning electrodes and a group of signal electrodes arranged so that picture elements are defined at the intersections therebetween and a bistable optical modulation material assuming one of two stable states applied between the groups of electrodes, by in a first phase orienting the bistable material at the picture elements on an N-th scanning electrode to one stable state, and applying a writing signal to the signal electrodes in synchronism with a scanning signal to the N-th scanning electrode while orienting the bistable material at the picture elements on an N+1-th scanning electrode to the one stable state.

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: An optical recording medium comprising a substrate and a thin organic film containing at least one kind of dye selected from polymethine family dyes, perylium family dyes, and cyanine family dyes, and a recording process comprising scanning the optical recording medium with a high intensity light beam such as a laser beam to form optically detectable pits on the recording medium.

Abstract: A liquid crystal device is constituted by (a) a pair of base plates each having an orientation control film thereon, and (b) a liquid crystal composition interposed between the base plates. The liquid crystal composition comprises a mixture including at least one liquid crystal compound which has a temperature range in which it shows chiral smectic phase and at least one optically active substance which does not have a temperature range in which it shows chiral smectic phase. The liquid crystal composition has a temperature range in which it shows cholesteric phase and is placed in chiral smectic phase which has been formed through cholesteric phase on temperature decrease. The liquid crystal composition comprises liquid crystal molecules having long axes forming a pre-tilt in the chiral smectic phase.

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 liquid crystal device is constituted by (a) a pair of base plates each having an orientation control film thereon, and (b) a liquid crystal composition interposed between the base plates. The liquid crystal composition comprises at least two liquid crystal compounds including at least one liquid crystal compound which has a temperature range in which it shows cholesteric phase. The liquid crystal composition has a temperature range in which it shows cholesteric phase and is placed in chiral smectic phase which has been formed through cholesteric phase on temperature decrease. The liquid crystal composition comprises liquid crystal molecules having long axes forming a pre-tilt in the chiral smectic phase.

Abstract: A driving method for an optical modulation device comprising matrix picture elements each formed at intersecting points of scanning lines and data lines between which a bistable optical modulation material represented by a ferroelectric liquid crystal is interposed. The driving method comprises an erasure step of applying a voltage signal orienting the optical modulation material to the first stable state between the scanning and data lines, at all or a part of the matrix picture elements, and a writing step of sequentially applying a scanning selection signal to the scanning lines and applying an information orientation signal orienting the optical modulation material to the second stable state to the data lines in phase with the scanning selection signal.

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: An optical recording medium comprising a substrate and a thin organic film containing at least one kind of dye selected from polymethine family dyes, perylium family dyes, and cyanine family dyes, and a recording process comprising scanning the optical recording medium with a high intensity light beam such as a laser beam to form optically detectable pits on the recording medium.

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.