Abstract: The invention provides novel cross-linkable, photoactive silane derivatives and mixtures with 3-aryl-acrylic acid esters and amides. The present invention also provides orienting layers for liquid crystals, and non-structured and structured optical elements and multi-layer systems based on the silane mixtures and derivatives.

Abstract: The use of an aqueous, synthetic composition containing Ca.sup.++ and having a controlled, specified pH value for revealing the presence of protein contamination on the membrane of a pH measuring electrode.

Abstract: An optical component includes a substrate or cell having two spaced-apart substrates, one or more orientation layers on the substrates and one or more anisotropic layers of cross-linked liquid crystalline monomers or oligomers with locally different orientation of the liquid crystal molecules. The surfaces of the orientation layers adjacent the liquid crystalline layers have orientation patterns with a defined parallel or fan-like line structure in locally limited regions. The average spacing between the lines of the fan-like line structure is not greater than the thickness of the liquid crystal layer and the angle between neighboring lines is not greater than 3.degree..

Abstract: Flourobenzyl ether derivatives of the formula ##STR1## and liquid crystalline mixtures which contain such compounds are prepared and employed in electro-optical display devices.

Abstract: Photocross-linkable naphthyl derivatives include compounds of the formula: ##STR1## wherein R.sup.1 and R.sup.2 each independently signify a cross-linkable group;S.sup.1 and S.sup.2 signify --(CY.sub.2).sub.m -, --O(CY.sub.2).sub.m -, --(CY.sub.2).sub.m O--, --(CY.sub.2).sub.m COO--, --(CY.sub.2).sub.m OOC--, --(Si?(CH.sub.3).sub.2 !O).sub.m -, --OCH.sub.2 (Si?(CH.sub.3).sub.2 !O).sub.m Si?(CH.sub.3).sub.2 !CH.sub.2 O-- or --NHCH.sub.2 (Si?(CH.sub.3).sub.2 !O).sub.m Si?(CH.sub.3).sub.2 !CH.sub.2 NH--;Y signifies hydrogen, fluorine or methyl;a signifies 0 or 1;b signifies 1 or 2, with the proviso that a+b=2;m signifies a whole number of 1 to 16;A.sup.1 and A.sup.2 each independently signify 1,4-phenylene, which is optionally mono- or multiply-substituted with halogen, cyano, methyl, methoxy and/or acetyl, pyridine-2,5-diyl, pyrimidine-2,5-diyl, trans-1,4-cyclohexylene or trans-1,3-dioxane-2,5-diyl; andZ.sup.1 and Z.sup.2 each independently signify a single bond, --CH.sub.2 CH.sub.2 --, --OCH.sub.2 --, --CH.

Abstract: The present invention is concerned with photo cross-linkable liquid crystalline compounds of the general formula ##STR1## wherein A.sup.1 and A.sup.2 each represent a cross-linkable, mesogenic residue,liquid crystalline mixtures which contain such compounds and their use in the cross-linked state as optical components.

Abstract: Compounds of the general formula ##STR1## have a pronounced tendency to form liquid crystalline S (smectic) phases. Thus, optically inactive compounds of the formula I also have a tilted smectic phase, in particular an S.sub.C phase, in addition to a nematic phase. In contrast, many optically active compounds of the formula I additionally have, inter alia, a tilted smectic chiral phase, in particular a chiral S.sub.C phase, in addition to a cholesteric phase. The stated compounds are therefore particularly suitable as components and as dopants, respectively, for the preparation of a very wide range of liquid crystalline mixtures. The class of compounds comprising compounds of the general formula I offers a broad range of novel components and mixtures for optimization and modification of liquid crystalline mixtures.

Abstract: Optically active .alpha.-bromo- or .alpha.-chlorocarboxylic compounds of the formula ##STR1## wherein X is bromine or chlorine;M is hydrogen, NR.sub.4.sup.+1 or a cation of an alkali or alkaline earth metal;R.sup.1 is hydrogen or lower alkyl;n is 0 or 1;R is hydrogen, C.sub.1 -C.sub.20 alkyl, or C.sub.1 -C.sub.20 alkyl substituted in the terminal position with --NR.sup.2.sub.2, --COOR.sup.2, --OR.sup.3, a free or protected --CHO group or a ring A;R.sup.2 is hydrogen or a lower alkyl;R.sup.3 is hydrogen or a protecting group;ring A is an unsubstituted or substituted ring; and* is a center of chirality,are prepared by enantioselectively hydrogenating, in the presence of a ruthenium complex of an optically active diphosphine ligand, a (Z)-.alpha.,.beta.-unsaturated compound of the general formula ##STR2## wherein R, n, X and M are as defined above.

Abstract: A distorted helix ferroelectric liquid crystal cell (DHF) is driven with a capacitance connected in series to the liquid crystal layer. Capacity is effected by either an external device (capacitor) or by incorporation of a insulator (dielectric) in the DHF cell. The value of the series capacity is typically smaller than about twice the capacity of the cell without the series capacitance. The capacitive drive circuit, DHF cell and method for driving the circuit and cell, function to shorten the switching times required by conventional cells.

Abstract: In liquid crystal display cells comprising a liquid crystal (7) disposed between two substrate plates (1,2) provided with drive electrodes (3,4), the orientation layer (5,6) on the inner sides of the plates where the electrodes are disposed comprises an oriented photopolymer layer. This layer is formed by irradiating photopolymer layer. This layer is formed by irradiating photoreactive material with linear polarized light.

Abstract: A ferroelectric liquid crystal display comprises two liquid crystal cells disposed one behind the other between two polarizers, one cell having line electrodes and the other having pixel electrodes. The pixel electrodes are driven with image information in synchronism with the line electrodes. The orientation and refractive index of the liquid crystal cells are so chosen that transmission is not substantially altered when the control voltages are reversed. The two displays are so actuated that the switching angle never exceeds .+-.22.5.degree.. The polarity of the voltages is periodically so inverted that on average there is no DC voltage across the cells.

Abstract: A compound of the formula ##STR1## wherein R is C.sub.1 -C.sub.7 alkyl or C.sub.2 -C.sub.12 alkenyl; rings A and B each independently are 1,4-phenylene,trans-1,4-cyclohexylene or trans-1,3-dioxane-2,5-diyl;Z.sup.1 is a single bond or --CH.sub.2 CH.sub.2 --; andZ.sup.2 is a single bond, --CH.sub.2 CH.sub.2 --, --OCH.sub.2 --,--C.tbd.C--, --COO-- or --OOC--; andm, n are 0 or 1, with the proviso that m+n.ltoreq.1;as well as liquid crystalline mixtures which contain such compounds and the use of such compounds and, respectively, mixtures for electro-optical display devices.

Abstract: The present invention is concerned with photo cross-linkable liquid crystalline compounds in the formula ##STR1## wherein for example: A,B,C,D,E,F independently is pyridine-2,5-diyl, pyrimidine-2,5-diyl, trans-1,4-cyclohexylene, trans-1,3-dioxane-2,5-diylZ.sup.1, Z.sup.2, Z.sup.7 independently is --(CH.sub.2).sub.s O--, --COO--, --(CH.sub.2).sub.s COO--Z.sup.3, Z.sup.4, Z.sup.8 independently is a single bond, --CH.sub.2 CH.sub.2 --, --CH.sub.2 O--Z.sup.5, Z.sup.6 independently is --(CH.sub.2).sub.s --m, n, q and r independently is 0, 1 or 2;s is a whole number of 1 to 16;R.sup.1, R.sup.2 independently is CH.sub.2 .dbd.CH--COO--, CH.sub.2 .dbd.C(CH.sub.3)--COO--R.sup.3 is H, CH, COOC.sub.n H.sub.2n+1, CnH.sub.2n+1 ; n=1 . . . 10X.sup.1, X.sup.2 and X.sup.3 independently is hydrogen, halogen, cyano or lower alkyl.The invention is also related to liquid crystalline mixtures and their use for electro-optical purpose.

Abstract: The image-producing device comprises a liquid crystal cell with a liquid crystal (10, 21, 44) between two plates provided with drive electrodes (2, 6; 24, 25; 42, 46) and wall orientation layer (3, 7; 26,27; 43, 45) and an optically anisotropic polymeric additional element (9, 31, 52). The additional element, which can be a separate element or in the form of a coating or a foil stuck directly to the cell, comprises an oriented photopolymer.

Abstract: A liquid crystal display cell comprising a chiral ferroelectric smectic liquid crystal layer whose helix structure is influenced by the action of an electric field such that its optical anisotropy alters; a pair of transparent plates between which the liquid crystal is disposed and which have a surface structure for aligning the molecule of the liquid crystal and are provided with electrodes to produce an electric field therein; and one polariser each before and after the liquid crystal: such ratio d/p of the thickness d of the liquid crystal layer to the pitch height p of the helical twisting is greater than 5, the smectic tilt angle .theta..sub.o is being between 22.5 .degree. and 50.degree. and the product d..theta..sub.o.sup.2..DELTA.n.1/.lambda. (phase factor) of the thickness d, the square of the tilt angle .theta..sub.o, the value of the birefringence .DELTA.n and the reciprocal of the wavelength .lambda. of light bedding is greater than 0.45 .mu.m.

Abstract: The commercial production of DHF cells, in particular a colored DHF display cell, has scarcely become established to date. This is because in particular such cells based on the known prior art expediently must possess a liquid crystal layer having a thickness d of about 1.4 to 2.8 .mu.m, which requires an expensive and complex production process. On the basis of the knowledge that the mean value of the refractive index of a DHF display can be described with that of a birefringent plate, it has now been found that the magnitude of the birefringence .DELTA.n changes significantly within a voltage range typical for DHF cells, in particular for DHF displays having a large switching angle .alpha.. The present invention therefore relates to the utilization of this second effect of the voltage dependence of .DELTA.n, with the object of substantially facilitating the production of DHF displays.

Abstract: Objects of this invention are cyclopentyl compounds of the general formula ##STR1## wherein k signifies a whole number of 4 to 18;n signifies 0 or 1;Y.sup.1, Y.sup.2 signify a single bond, --O--, --COO-- or --OOC--;rings A, B, C each independently signify optionally mono- or difluorinated 1,4-phenylene, pyrimidine-2,5-diyl, pyridine-2,5-diyl, pyrazine-2,5-diyl, naphthalene-2,6-diyl, quinoline-2,6-diyl, thiophene-2,5-diyl, thiazole-2,5-diyl or 1,3,4-thiadiazole-2,5-diyl and ring C also signifies trans-1,4-cyclohexylene or trans-1,3-dioxane-2,5-diyl;Z.sup.1 signifies a single bond, --COO--,--OOC-- or --C.tbd.C--;Z.sup.2 signifies --COO--, --OOC--, --OCH.sub.2 --, --CH.sub.2 O-- or --(CH.sub.2).sub.

Abstract: The present invention is concerned with chromophore-containing photo cross-linkable liquid crystalline compounds having the formula ##STR1## wherein A.sup.1 and A.sup.2 each represent a cross-linkable, mesogenic group; andA.sup.3 represents a dichroic group.as well as liquid crystalline mixtures which contain such compounds and their use in the cross-linked state as optical components.

Abstract: The present invention is concerned with photo cross-linkable liquid crystalline compounds of the general formula ##STR1## wherein A.sup.1 and A.sup.2 each are a cross-linkable mesogenic residue; andA.sup.3 is (R,R)- or (S,S)-trans-1,2-cyclohexyl-diyl,liquid crystalline mixtures which contain such compounds and their use in the cross-linked state as optical components.

Abstract: Colors are generated in the display device by guiding light through three serially-arranged, electrically controlled color filters. Each filer attenuates one of three colors. The color filters incorporate two cholesteric filters, two .lambda./4 plates, and one electrically switchable liquid crystal display.