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 modulation material at the picture elements on an N+1-th scanning electrode to the one stable state.

Abstract: A liquid crystal composition contains a mesomorphic compound represented by the following formula (A): ##STR1## wherein R.sub.1 denotes a linear or branched alkyl group having 1-18 carbon atoms; X.sub.1 denotes a single bond, --O--, --CO--O-- or --O--CO--; X.sub.2 denotes a single bond, --OCH.sub.2 --, --CO--O-- or --O--CO--; n is an integer of 3-16; and A.sub.1 denotes ##STR2## and a mesomorphic compound represented by the following formula (B): ##STR3## wherein R.sub.2 denotes a linear or branched alkyl group having 1-18 carbon atoms; X.sub.3 and X.sub.4 independently denote a single bond, --O--, --CO--O-- or --O--CO--; m is an integer of 3-16; and A.sub.2 denotes ##STR4## The liquid crystal composition may preferably be formulated as a chiral smectic liquid crystal composition. The liquid crystal composition is useful in providing a liquid crystal device using the liquid crystal composition with a good alignment characteristic, a good drive characteristic, and a high contrast ratio.

Abstract: A liquid crystal apparatus comprises a liquid crystal device including scanning electrodes and signal electrodes intersecting each other, and a chiral smectic liquid crystal disposed therebetween. The chiral smectic liquid crystal assumes a first orientation state when supplied with a pulse voltage of one polarity exceeding a first threshold voltage, a second orientation state when supplied with a pulse voltage of the other polarity exceeding a second threshold voltage, and a third orientation state when released from application of the pulse voltage of one or the other polarity.

Abstract: A liquid crystal apparatus comprises a liquid crystal device comprising a group of scanning electrodes and a group of signal electrodes intersecting each other to form an electrode matrix, and a chiral smectic liquid crystal disposed so as to form a picture element at each intersection of the scanning electrodes and the signal electrodes.

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 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 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 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 liquid crystal device including: a pair of substrates and a chiral smectic liquid crystal disposed between the pair of substrates. Each of the pair of substrates has an electrode for applying a voltage to the liquid crystal. The pair of substrates is provided with respective uniaxial alignment axes extending in directions which are parallel to each other or intersect each other at a prescribed angle. The chiral smectic liquid crystal is placed in such an alignment state that the liquid crystal assumes at least two stable states and provides a pretilt angle .alpha. (degrees), a tilt angle H (degrees), an inclination angle .delta. (degrees) of the liquid crystal layer, and an apparent tilt angle .theta.a satisfying the following relationships (I) and (II) in a temperature range of 10.degree.-55.degree. C.:H<.alpha.+.delta. and .delta.<.alpha. (I), andH>.theta.a>H/2 (II).The liquid crystal provides a tilt angle H (degrees), an inclination angle .delta.

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 spaced from the group of scanning electrodes, and an optical modulation material (e.g. a liquid crystal) showing histability with respect to an electric field applied thereto disposed between the groups of scanning electrodes and signal electrodes.

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 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 or branched alkyl group having 1-18 carbon atoms capable of having a subtituent; X.sub.1 denotes a single bond, ##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 optically inactive alkyl group having 1-18 carbon atoms capable of having an alkoxy group of 1-12 carbon atoms; X.sub.2 and X.sub.3 respectively denote a single bond, ##STR6## and p and q are respectively 0, 1 or 2 with proviso that both of p and q are not 0.

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 apparatus comprises a liquid crystal device having scanning electrodes arranged in a matrix with and spaced apart from signal electrodes with a liquid crystal showing different stable states in accordance with different applied voltages and having a memory function disposed therebetween. First drive circuitry selects and sequentially drives the scanning electrodes by application of a scanning selection signal, and second drive circuitry drives the signal electrodes by application of a writing voltage and a first non-writing voltage corresponding to display contents in synchronism with the application of the scanning selection signal. The first drive circuitry applies reset voltages to the pixels of the liquid crystal to make orientation of the liquid crystal's molecules uniform before the selection of the scanning electrode.

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, ##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.

Abstract: A driving method is provided for driving an optical modulation device. The device has picture elements arranged in the form of a matrix consisting of a plurality of rows and a plurality of columns defined by the intersections of scanning electrodes and signal electrodes, and a liquid crystal having a memory function. The picture elements in each row are selectively supplied with either a voltage for orienting the liquid crystal to one display state, or another voltage for orienting the liquid crystal to another display state.

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 crsytal 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: An optical modulation apparatus has a matrix electrode arrangement comprising scanning electrodes and signal electrodes oppositely spaced from the scanning electrodes. Scanning signals are selectively applied sequentially and periodically to the scanning electrodes and information signals are selectively applied to the signal electrodes in synchronism with the scanning signals to effect optical modulation of an optical modulation material showing a first stable state and a second stable state with respect to an electric field applied thereto interposed between the scanning and signal electrodes.

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, ##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 and R.sub.4 respectively denote a linear or branched alkyl group having 1-18 carbon atoms capable of having a substituent, at least one of R.sub.3 and R.sub.4 being optically active; and; X.sub.3 and 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 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.2 respectively denote a single bond, --O--, ##STR2## 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.3 and X.sub.4 respectively denote a single bond, --O--, ##STR4## Z.sub.1 denotes ##STR5## --CH.sub.2 O--, --OCH.sub.2 -- or a single bond; ##STR6## respectively denote ##STR7## denotes ##STR8## with proviso that at least one of ##STR9## and at least one compound represented by the following formula (III): ##STR10## wherein R.sub.

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 spaced from the group of scanning electrodes, and an optical modulation material (e.g. a liquid crystal) showing bistability with respect to an electric filed applied thereto disposed between the groups of scanning electrodes and signal electrodes.