Abstract: Compounds with the general formula (I): R—S1—A—Z1—B—S2—R, where A and B are independent ring systems with the formulae (a1), (a2) or (b), whereby in the trans-1,4-cyclohexylene ring, one or two non-adjacent CH2 groups may be replaced by oxygen, and whereby, in the 1,4-phenylene ring, one or two non-adjacent CH groups may be replaced by nitrogen; L1, L2, L3 represent, independently, hydrogen, C1-C20-alkyl, C1-C20-alkenyl, C1-C20-alkyloxy, C1-C20-alkyloxy carbonyl, formyl, C1C20-alkyl carbonyl, C1-C20-alkyl carbonyloxy, halogen, cyano or nitro; Z1, Z2, Z3 represent, independently, a single bond, —CH2CH2—, —CH2O—, —OCH2—, —COO—, —OOC—, —(CH2)4—, —O(CH2)3—, —(CH2)3O— or —C≡C—; S1, S2 represent a spacer unit; R represents crosslinkable groups, with the proviso that at least one of the ring systems A or B represents a ring system with the formula (a1

Abstract: A polarization mask for producing light of locally different polarization from unpolarized or uniformly polarized light. On the light output side, discrete areas with different polarization directions are present, which are either static or switchable. The mask is useful for, among other things, the transfer of polarization pattern onto a PPN layer.

Abstract: The invention relates to novel crosslinkable, photoactive polymers from the class of polyimides, polyamide acids and esters thereof, and to their use as orientation layers for liquid crystals and in the construction of unstructured and structured optical elements and multi-layer systems. The polymers contain as side-chains photo-crosslinkable groups of the following formula: The broken line indicates the point of linkage to the polymer main chain. In addition, A, B each independently of the other represents unsubstituted or optionally fluoro-, chloro-, cyano-, alkyl-, alkoxy-, fluoroalkyl- or fluoroalkoxy-substituted phenylene, pyridine-2,5-diyl, pyrimidine-2,5-diyl, cyclohexane-1,4-diyl, piperidine-1,4-diyl, piperazine-1,4-diyl; C represents unsubstituted or optionally fluoro-, chloro-, cyano-, alkyl-, alkoxy-, fluoroalkyl- or fluoroalkoxy-substituted phenylene, or pyrimidine-2,5-diyl, pyridine-2,5-diyl, 2,5-thiophenylene, 2,5-furanylene, 1,4- or 2,6-naphthylene.

Abstract: The invention is concerned with novel cross-linkable, photoactive polymer materials with 3-aryl-acrylic acid esters and amides as well as their use as orienting layers for liquid crystals and for the production of non-structured or structured optical elements and multi-layer systems.

Abstract: An optical component having a hybrid layer structure includes an orienting layer, a further layer in contact with the orienting layer and incorporating a cross-linked liquid crystalline monomer and at least one additional orienting layer on top of the liquid crystalline layer, and preferably includes one additional cross-linked liquid crystalline monomer. The layers have different functions, such as orienting or retarding. At least one of the orienting layers should be a photo-orientating polymer network layer, or have locally varying orienting pattern. These optical components are useful in transmittance and reflective liquid crystal displays, such as rotation cells, STN cells, ferroelectric cells, and cells having an addressable active matrix. Such cells are useful in optical and integrated optical devices, and may be used for safeguarding against counterfeiting and copying in transmission.

Abstract: Orientation layers of monomeric or polymeric liquid crystal layers having any desired azimuthal orientation direction and a tilt angle are produced by irradiating at an angle differing from the normal to the surface photopolymers orienting parallel to linearly polarized light.

Abstract: The invention relates to novel crosslinkable, photoactive silane derivatives of the formula I mixtures of silane derivatives of the formula I and mixtures of silane derivatives of the formula I with uncrosslinkable silane derivatives as usually used for silanizing inorganic, oxide-containing surfaces. The invention furthermore relates to the use of silane derivatives of the formula I and of mixtures which contain at least one silane derivative of the formula I as orientation layers for liquid crystals and for the production of unstructured or structured optical elements and multilayer systems.

Abstract: Liquid cell crystal, with fine structures made up of regions having defined different orientation and dimensions of the order of 0.1 to about 100 &mgr;m can be used as optical conductors and projection displays. The fine structures in the liquid crystals are produced in that the plates bounding and guiding the liquid crystal are provided with micromechanically produced regions having different defined preferred directions. The result is a molecular orientation having a higher refractive index that the surrounding region for guiding and polarizing irradiated light. The orienting layers on the plates bounding the liquid crystal are micromechanically structured in that certain spatial regions are mechanically structured in a uniform direction by a stylus moved by piezoelectric means.

Abstract: A compound of formula in which R1 and R2 each independently represent and alkyl or alkenyl group in which one or more hydrogen atoms is optionaly substituted by fluorine, chlorine, or cyano; and in which optionally one or more non-adjacent methylene groups are optionaly replaced by —O—, —COO— or —OOC—; Z1 to Z4 each independently represent a single bond, —CH2CH2—, —CH2O—, —OCH2—, —C≡C—, —(CH2)4—, —(CH2)3O—, —CH═CH—CH2O—, OCH2—, —CH═CH—, —CH═CH—(CH2)2— or —(CH2)2—CH═CH—, with the proviso firstly that the oxygen atom is not linked directly with the chiral dioxane ring and secondly Z2 and Z3 may also represent —COO— or —OOC—; R* and S* signify that the denoted carbon have the (R) or (S) configuration respectively or the optical antipode thereof; and one of A, B and

Abstract: Orientation layers of monomeric or polymeric liquid crystal layers having any desired azimuthal orientation direction and a tilt angle are produced by irradiating at an angle differing from the normal to the surface photopolymers orienting parallel to linearly polarized light.

Abstract: A polymer having the formula wherein M1 and M2 signify monomer units for homo- or copolymers. “x” and “y” indicate the mole fractions of the comonomers, with in each case 0<x≦1 and 0≦y<1 and x+y=1. The symbol “p” signifies 4 to 30,000 and “S1” and “S2” signify spacer units. “Q1” signifies a structural unit of the formula —A—(Z1—B)z—Z2— and “Q2” signifies a structural unit of the formula —A—(Z1—B)zR1. “A” and “B” each independently signify pyridine-2,5-diyl, pyrimidine-2,5-diyl, 1,4—Cyclohexylene,1,3-dioxane-2,5-diyl or optionally substituted 1,4-phenylene.

Abstract: A driving method comprising providing preparatory pulses to each pixel, which establish a predetermined voltage prior to the data pulses. The preparatory pulses may either unload the pixel to a resulting potential of 0 V or load it to a resulting voltage of the same polarity as the charge on the pixel in the subsequent frame time.

Abstract: An optical component having a hybrid layer structure includes an orienting layer, a further layer in contact with the orienting layer and incorporating a cross-linked liquid crystalline monomer and at least one additional orienting layer on top of the liquid crystalline layer, and preferably includes one additional cross-linked liquid crystalline monomer. The layers have different functions, such as orienting or retarding. At least one of the orienting layers should be a photo-orientating polymer network layer, or have locally varying orienting pattern. These optical components are useful in transmittance and reflective liquid crystal displays, such as rotation cells, STN cells, ferroelectric cells, and cells having an addressable active matrix. Such cells are useful in optical and integrated optical devices, and may be used for safeguarding against counterfeiting and copying in transmission.

Abstract: An optical frequency conversion element has a wave-guiding layer which consists of a .chi..sup.(2) -active ferroelectric liquid crystal. The monomeric or polymeric liquid crystal material has a periodic structure which permits the so-called quasi phase matching of a guided laser beam. The period length of the structure is equal to twice the coherence length l.sub.c =.pi./.DELTA..beta. of the material, whereby .DELTA..beta.=.beta..sub.o (2.omega.)-2.beta..sub.o (.omega.), with .omega.=angular frequency of the fundamental wave, 0=zero-order mode and .beta.=propagation constant of the mode.

Abstract: By combination of a hybrid layer formed from an orienting layer and a layer of a cross-linked liquid crystalline monomer with a reflector, and by appropriate local structuring of the molecule orientation, an optical pattern is obtained which cannot be copied using conventional photocopiers. This pattern is useful as means for protecting documents, such as banknotes, credit cards, and the like, from being copied, and can be detected by manually or automatically, operated optical reading devices.

Abstract: Polymerisable optically active compounds have the general formula: ##STR1## where: W.sup.1 denotes a polymerisable residue,S.sup.1 denotes a spacer unit,Y.sup.1 denotes a single bond, or one of the groups --O--, --COO--, --OOC--, --OCOO--, --S--, --CONH-- or --NHCO--,M denotes a divalent mesogenic group, andR.sup.1 and R.sup.2 denote straight chain, branched or cyclic alkyl groups with up to 8 carbon atom.

Abstract: The commercial production of DHF (Deformed Helix Ferroelectric) cells, in particular DHF color display cells, has scarcely become established to date. This is in particular because the DHF cells required for this purpose and based on the known prior art have short switching times and a good angular range of view but relatively high voltages and currents are required for their operation. Moreover, for the production of a DHF cell, the liquid crystal mixture must additionally be oriented or formatted by means of an electric field. The present invention relates to a ferroelectric display cell which does not have these disadvantages and in particular is distinguished by the fact thatthe display is dark at U=0 and bright at .vertline.U.vertline.>0,the current-voltage hysteresis characteristic has two maxima of equal size,the birefringence .DELTA.n in the field-free state is greater than that in the saturated state andthe saturation voltage is relatively low even with very small spontaneous polarization P.sub.

Abstract: The invention is concerned with novel cross-linkable, photoactive polymer materials with 3-aryl-acrylic acid esters and amides as well as their use as orienting layers for liquid crystals and for the production of non-structured or structured optical elements and multi-layer systems.

Abstract: Known liquid crystal cells have a nematic liquid crystal configuration and, in accordance with this configuration, are referred to as TN or STN cells. It is true that such cells are adequate for many applications. However, their image quality is dependent to a very great extent on the user's angle of view. Furthermore, TN and STN cells require a continuously applied signal voltage if it is intended to display or store information on one. Bistable liquid crystal cells having a ferroelectric, chiral smectic liquid crystal layer do not have these disadvantages of nematic display cells. However, the commercial production of such bistable display cells has scarcely become established to date. This is in particular because they are not very suitable for reliably storing information or do not permit absolutely equivalent switching between the two bistable positions of the director. The invention now proposes a novel, bistable liquid crystal cell which avoids precisely these disadvantages.

Abstract: The invention is concerned with linear and cyclic polymers or oligomers having a photoreactive ethene group. The polymers are of the formula ##STR1## wherein M.sub.a, M.sub.b, M.sub.c are monomer units for homo- or copolymers;x, y, z are mole fractions of the copolymers, whereby in each case 0<x.ltoreq.1; 0.ltoreq.y.ltoreq.1 and 0.ltoreq.z<1;S.sub.a, S.sub.b are spacer units;Z.sub.a, Z.sub.b are molecular units which can undergo photochemical isomerization/dimerization;n is a magnitude of 4-100 000 andm is 0 or 1,The compounds are used as an orienting layer for liquid cyrstals.