Abstract: An optically inactive mesomorphic compound represented by the following formula (I): ##STR1## wherein R denotes a linear or branched alkyl group having 1-18 carbon atoms or a linear or branched alkoxy group having 1-18 carbon atoms; and m is an integer of 2-18, is suitable as a component for a liquid crystal composition providing improved response characteristics and a high contrast. A liquid crystal device is constituted by disposing the liquid crystal composition between a pair of substrates. The liquid crystal device may preferably be used as a display panel constituting a liquid crystal apparatus providing good display characteristics.

Abstract: A mesomorphic compound of the formula (I) according to claim 1 is suitable as a component for a liquid crystal composition providing improved response speed and decreased. The mesomorphic compound of the formula (I) is characterized by having at least one terminal cyclic group free from a side chain and also having a core structure including at least one group ##STR1## The above liquid crystal composition is useful as an element of a liquid crystal device and a display apparatus providing a good display characteristics.

Abstract: An optically inactive mesomorphic compound of the formula (I) according to claim 1 characterized by having a terminal group of: --A.sub.3 --C.sub.r F.sub.2r+1, where A.sub.3 is a specific cyclic group and r is 2-18, is suitable as a component for a liquid crystal composition providing improved response characteristics and a high contrast. A liquid crystal device is constituted by disposing the liquid crystal composition between a pair of electrode plates. The liquid crystal device is used as a display panel constituting a display apparatus (or display method) providing good display characteristics.

Abstract: A quinoxaline compound of the formula (I) according to claim 1 characterized by having at least one quinoxaline-2,6 (or 2,7)-diyl group is suitable as a component for a liquid crystal composition providing improved response characteristics and a high contrast. A liquid crystal device is constituted by disposing the liquid crystal composition between a pair of electrode plates. The liquid crystal device is used as a display panel constituting a display apparatus providing good display characteristics.

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 1-12 carbon atoms; X.sub.1 denotes a single bond, ##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, at least one of R.sub.3 and R.sub.4 being optically active; and X.sub.2 and X.sub.

Abstract: A ferroelectric chiral smectic liquid crystal composition is provided with a fast response speed and a less temperature dependency of the response speed by containing at least one mesomorphic compound represented by the formula (1) below: ##STR1## wherein R.sub.1 denotes an alkyl group having 1-16 carbon atoms and capable of having a substituent; R.sub.2 denotes an alkyl group, alkoxy group, alkoxycarbonyl group, acyloxy group or alkoxycarbonyloxy group each having 1-16 carbon atoms and capable of having a substituent; and ##STR2## respectively denotes ##STR3## each capable of having a substituent.

Abstract: A mesomorphic compound of the formula (I) according to claim 1 characterized by having at least one cyclic group selected from .beta. class including, e.g., thiazole-2,5-diyl, benzoxazole-2,5-diyl, indan-2,5-diyl, and quinoxaline-2,6-diyl and also having a linkage of Y.sup.1 (CH.sub.2).sub.m Y.sup.2, where Y.sup.1 and Y.sup.2 are --CH.sub.2 --, --O--, --COO-- or --OCO-- and m is 1-16, is suitable as a component for a liquid crystal composition providing improved response characteristics. A liquid crystal device is constituted by disposing the liquid crystal composition between a pair of substrates. The liquid crystal device is used as a display panel constituting a liquid crystal apparatus providing good display characteristics.

Abstract: A liquid crystal device is formed by applying an alignment film on at least one of a pair of substrates sandwiching a liquid crystal, preferably a chiral smectic liquid crystal. The alignment is formed by a dehydro-cyclization product of a polyamide acid which in turn is a reaction product of naphthalenetetracarboxylic acid or its derivative with a diamine or its derivative. The liquid crystal device provides a high contrast display, particularly by multiplexing drive, which is free from after-image because of quick responsiveness.

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 1-18 carbon atoms capable of including one or two or more non-neighboring methylene groups which can be replaced with ##STR2## wherein X denotes halogen; X.sub.1 and X.sub.2 respectively denote ##STR3## Z.sub.1 denotes ##STR4## A.sub.1 denotes a single bond, ##STR5## and Y.sub.1 and Y.sub.2 respectively denote H, F, Cl, Br, --CH.sub.3 or --CF.sub.3 with the proviso that Y.sub.1 and Y.sub.2 are not simultaneously H. The mesomorphic compound is effective for providing a ferroelectric liquid crystal composition showing an improved low-temperature operation characteristic and a decreased temperature-dependence of response speed.

Abstract: A ferroelectric chiral smectic liquid crystal composition is provided with a fast response speed and a less temperature dependency of the response speed by containing at least one mesomorphic compound represented by the formula (1) below: ##STR1## wherein R.sub.1 denotes an alkyl group having 1-16 carbon atoms and capable of having a substituent; R.sub.2 denotes an alkyl group, alkoxy group, alkoxycarbonyl group, acyloxy group or alkoxycarbonyloxy group each having 1-16 carbon atoms and capable of having a substituent; and ##STR2## respectively denotes ##STR3## each capable of having a substituent.

Abstract: A mesomorphic compound of the formula (I) according to claim 1 is suitable as a component for liquid crystal composition providing improved response characteristics.

Abstract: An optical disk apparatus has a galvanic mirror error signal generation circuit for detecting that the galvanic mirror rotates more than an allowed limit value in directions P and Q. When it is detected by the galvanic mirror error signal generation circuit that the galvanic mirror rotates more than the allowed limit value, the light intensity of the light spot is changed from the recording-use (or erasing-use) light intensity into the reproducing-use light intensity. Accordingly, recording and erasing of information is always carried out by the projection of the light beam having a predetermined light intensity, thereby always providing a high grade of optical disk apparatus.

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: The first control data generating circuit continuously controls the output light-amount of a light source with respect to an optical disk that has not been formatted. In contrast, the second control data generating circuit controls the output light-amount of the light source at each of a plurality of sectors with respect to an optical disk that has been formatted. A discrimination circuit discriminates whether or not the optical disk has been formatted according to a detection of a header of each sector. According to a result of the discrimination of the circuit, a switch alley switches controlling operations between the first light-amount controlling operation and the second light-amount controlling operation. The difference between those two types of controlling operations merely lies in whether timing for controlling the light amount is dependent on each sector or not.

Abstract: A mesomorphic compound of the formula (I) according to Claim 1 and an optically active compound of the formula (II) according to Claim 2 are suitable as a component for a liquid crystal composition providing improved response characteristics and having an improved helical pitch at a cholesteric phase or a chiral smectic C phase. The above liquid crystal composition is useful as an element of a liquid crystal device providing a good display characteristics including a gradation display.

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 mesomorphic compound represented by the following formula (I): ##STR1## wherein R.sub.1 and R.sub.2 respectively denote an alkyl group or alkoxy group each having 4-16 carbon atoms optionally substituted, halogen, --CN or --CF.sub.3. The mesomorphic compound is effective for providing a ferroelectric liquid crystal composition showing an improved low-temperature operation characteristic and a decreased temperature-dependence of response speed.

Abstract: An information reproducing apparatus which has a rotating driver for rotating a disc-shaped recording medium, a floating-type head for reproducing information recorded in the recording medium while floating above the disc-shaped recording medium that is being rotated by the rotating driver, and a suspension, made of an elastic member, for supporting the floating-type head. The information reproducing apparatus is characterized in that the floating-type head has a slider which is floated by an air flow that is directed near the surface of the rotating disc-shaped recording medium, and that the slider has a bevelled portion at one side that faces the outer edge of the disc-shaped recording medium such that any contact between the slider and the ridge that exists along the outer edge area of the disc-shaped recording medium is virtually eliminated.

Abstract: A mesomorphic compound represented by the following formula (I):R.sub.1 --A.sub.1 --B.sub.1 --A.sub.2 --R.sub.2 (I),wherein R.sub.1 and R.sub.2 respectively denote a linear or branched alkyl group having 3-18 carbon atoms capable of including one or non-neighboring two or more methylene groups which can be replaced with at least one species of --Z--, ##STR1## CH.dbd.CH-- and --C.tbd.C--, wherein Z denotes --O-- or --S-- and R.sub.3 denotes hydrogen or an alkyl group having 1-5 carbon atoms; B.sub.1 denotes ##STR2## A.sub.1 denotes a single bond, ##STR3## A.sub.2 denotes a single bond, --A.sub.3 -- or --A.sub.3 --A.sub.4 -- wherein A.sub.3 and A.sub.4 respectively denote any one of ##STR4## and Y.sub.1 and Y.sub.2 respectively denote any one of hydrogen, fluorine, chlorine, bromine, --CH.sub.3, --CN and --CF.sub.3.