Abstract: A parallel driving device that drives parallel-connected semiconductor elements includes a control unit and a gate driving circuit. The control unit detects a temperature difference between the semiconductor elements on the basis of detected values by temperature sensors that detect temperatures of the individual semiconductor elements. The control unit generates a control signal for changing the timing at which to turn on a first semiconductor element specified from the semiconductor elements on the basis of the temperature difference. The gate driving circuit generates a first driving signal for driving the semiconductor elements, and generates a second driving signal that is the first driving signal delayed on the basis of the control signal, and applies the second driving signal to the first semiconductor element.

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 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 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 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 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 substituent; R.sub.2 denotes a linear or branched alkyl group having 1-14 carbon atoms capable of having a substituent; and X.sub.1 denotes a single bond, ##STR2## and at least one optically active compound represented by the following formula (II): ##STR3## wherein R.sub.3 denotes a linear alkyl group having 1-14 carbon atoms; R.sub.4 denotes a linear or branched alkyl group having 1-14 carbon atoms capable of having a substituent; and X.sub.