Abstract: The invention relates to a liquid-crystalline medium based on a mixture of polar compounds having negative dielectric anisotropy, which contains at least one compound of the formula I and at least one compound of the formula II in which R1, R2, R3, R4, ring A, Z1, Z2 and m are as defined in Claim 1, and to the use thereof for an active-matrix display based on the ECB, VA, PS-VA, FFS, PALC or IPS effect.

Abstract: To provide a liquid crystal display panel that has high contrast and reduced display deficiency, a liquid crystal display panel of the present invention includes: a pair of substrates (1) and (2) facing each other; and a liquid crystal layer (3) sandwiched between the pair of substrates (1) and (2), the pair of substrates (1) and (2) being provided with a pair of respective alignment films (4) and (5) formed thereon and facing each other, the pair of alignment films (4) and (5) being provided with respective polymer films (6) and (7) formed thereon and each made of a monomer in the liquid crystal layer (3), the pair of alignment films (4) and (5) containing a macromolecular compound having a side chain containing a fluorine atom, the liquid crystal layer (3) containing a polymerizable monomer represented by at least one of General Formulae (1) through (3), the polymer films (6) and (7) each being made of the polymerizable monomer represented by at least one of General Formulae (1) through (3), the polymer fil

Abstract: The invention provides a liquid crystal composition satisfying at least one of characteristics such as a high maximum temperature of a nematic phase, a low minimum temperature of the nematic phase, a small viscosity, a large optical anisotropy, a large positive dielectric anisotropy, a large specific resistance, a high stability to ultraviolet light and a high stability to heat, or provides a liquid crystal composition having a suitable balance regarding at least two of the characteristics. A liquid crystal display device containing such a liquid crystal composition is applied as an AM device having a short response time, a large voltage holding ratio, a large contrast ratio, a long service life and so forth, and thus can be suitably used for a liquid crystal projector, a liquid crystal television and so forth.

Abstract: A liquid crystal compound is described, which has stability to heat, light and so forth, keeps a nematic phase in a wide temperature range, has a small viscosity, a suitable optical anisotropy and a suitable elastic constant K33, and further has a large negative dielectric anisotropy and an excellent compatibility with other liquid crystal compounds. The liquid crystal compound is represented by formula (1): wherein, for example, R1 is alkyl having 1 to 10 carbons, R2 is alkoxy having 1 to 10 carbons; ring A1, ring A2 and ring A5 are 1,4-cyclohexylene, 1,4-phenylene, or 1,4-phenylene in which arbitrary hydrogen is replaced by fluorine; Z1 and Z4 are a single bond, —CH2CH2— or —CH?CH—; a, b and e are 0 or 1, and c and d is 0; X1, X2 and X4 are hydrogen, and X3 is fluorine; and L1 and L2 are fluorine.

Abstract: To provide a novel liquid crystal compound having general physical properties necessary for the compound, namely, stability to heat, light and so forth, a wide temperature range of a liquid crystal phase, a high clearing point, a good compatibility with other compounds, a large refractive index anisotropy, a large dielectric anisotropy and a small viscosity. The liquid crystal compound is provided as compound (1): wherein, for example, R1 is alkyl having 1 to 20 carbons; ring A1 and ring B1 are 1,4-cyclohexylene or 1,4-phenylene; Z1 and Z2 are a single bond, —CH2CH2—, —CH?CH— or —C?C—; L1 is fluorine; L2, Y1 and Y2 are hydrogen, fluorine or chlorine; and X1 is halogen, —C?N or alkyl having 1 to 10 carbons, and in the alkyl, arbitrary —CH2— may be replaced by —O— or —S—, and m is 1 and n is 0.

Abstract: Providing a liquid crystal composition satisfies at least one of characteristics like a high maximum temperature of a nematic phase, a low minimum temperature of the nematic phase, a small viscosity, a suitable optical anisotropy, a large negative dielectric anisotropy, a large specific resistance, a high stability to ultraviolet light and a high stability to heat or has a suitable balance regarding at least two of the characteristics. Providing an AM device has a short response time, a large voltage holding ratio, a large contrast ratio, a long service life and so forth. The liquid crystal composition has a negative dielectric anisotropy and contains a specific compound having large negative dielectric anisotropy as a first component, a specific three-ring compound having large optical anisotropy as a second component and a specific two-ring compound having low viscosity as a third component, and a liquid crystal display device contains the composition.

Abstract: Provided are a liquid crystal composition containing, as a first component, a polymerizable compound represented by general formula (I): R11—S11-L11-(M11-L12)m-M12-L13-(M13-L14)n-Z11??(I) and a liquid crystal display element using the liquid crystal composition.

Abstract: An object is to provide a liquid crystal composition which exhibits a blue phase in a wide temperature range. Another object is to provide a liquid crystal composition which exhibits a blue phase, with which high contrast can be provided, in a liquid crystal display device. A liquid crystal composition which exhibits a blue phase includes: a nematic liquid crystal including a compound represented by a structural formula (100) (PPEP-5FCNF (abbreviation)); and a chiral agent. In a liquid crystal display device, a liquid crystal layer is formed using the liquid crystal composition including a nematic liquid crystal including a compound represented by a structural formula (100) (PPEP-5FCNF (abbreviation)) and a chiral agent, and the liquid crystal composition exhibits a blue phase.

Abstract: The present invention relates to liquid-crystal displays (LC displays) with polymer-stabilised, homeotropic (vertical) alignment of the liquid-crystalline medium (LC medium) without conventional imide alignment layers. The LC medium according to the invention comprises particles having a mass of at least 450 Da which have been functionalised by a polar, organic anchor group.

Abstract: The subject is to provide a liquid crystal composition that satisfies at least one of characteristics such as a high maximum temperature of a nematic phase, a low minimum temperature of a nematic phase, a small viscosity, a suitable optical anisotropy, a large dielectric anisotropy, a large specific resistance, a high stability to ultraviolet light, a high stability to heat and a large elastic constant, or that is suitably balanced regarding at least two of the characteristics. The subject is to provide an AM device that has a short response time, a large voltage holding ratio, a large contrast ratio, a long service life and so forth.

Abstract: The subject is to provide a liquid crystal that has a high stability to heat, light and so forth, a wide temperature range of a nematic phase, a small viscosity, a large optical anisotropy and a suitable elastic constant K33, and further has a large negative dielectric anisotropy and an excellent compatibility with any other liquid crystal compound. The invention provides the compound (1): wherein, for example, R1 and R2 are hydrogen, alkyl having 1 to 10 carbons, alkenyl having 2 to 10 carbons, alkoxy having 1 to 9 carbons, alkoxyalkyl having 2 to 9 carbons or alkenyloxy having 2 to 9 carbons; when one of the ring A1, the ring A2 and the ring A3 is 1,4-phenylene or 2,3-difluoro-1,4-phenylene, the other two are 1,4-cyclohexylene or 1,4-cyclohexenylene; and Z1 is a single bond, —(CH2)2—, —CH2O—, —OCH2—, —COO— or —OCO—.

Abstract: Switchable gas permeation membranes in which a photo-switchable low-molecular-weight liquid crystalline (LC) material acts as the active element, and a method of making such membranes. Different LC eutectic mixtures were doped with mesogenic azo dyes and infused into track-etched porous membranes with regular cylindrical pores. Photo-induced isothermal phase changes in the imbibed mesogenic material afforded large, reversible changes in the permeability of the photo-switchable membrane to nitrogen. For example, membranes imbibed with a photo-switchable cyanobiphenyl LC material demonstrated low permeability in the nematic state, while the photo-generated isotropic state demonstrated a 16×-greater sorption coefficient. Both states obey a high linear sorption behavior in accordance with Henry's Law. In contrast, membranes imbibed with a photo-switchable phenyl benzoate LC material showed the opposite permeability behavior to the biphenyl-imbibed membrane, along with nonlinear sorption behavior.

Abstract: A liquid crystal composition with which generation of an alignment defect in a polymer/liquid crystal composite exhibiting a polymer-stabilized blue phase can be reduced is provided. The liquid crystal composition includes a liquid crystal material exhibiting a blue phase; and a liquid crystalline monomer. In the liquid crystalline monomer, the chain length (the sum of carbon atoms and oxygen atoms) of an oxyalkylene group represented as Y in the following general formula (G1) is n (2?n?11). The liquid crystalline monomer has a lower phase transition temperature from a nematic phase to an isotropic phase (TNI) than liquid crystalline monomers including the oxyalkylene groups whose chain lengths are (n?1) and (n+1). In (G1), X represents a mesogenic skeleton; Y represents an oxyalkylene group (including carbon and oxygen), and includes hydrogen or fluorine; and Z1 and Z2 individually represent an acryloyl group or a methacryloyl group.

Abstract: A liquid crystal compound with branched alkyl or branched alkenyl as represented by formula (1), a liquid crystal medium (a liquid crystal composition or a polymer/liquid crystal composite material) containing the liquid crystal compound, and an optical element containing the liquid crystal medium are described. In formula (1), R1 is branched alkyl of C3-20 or branched alkenyl of C3-20. The ring A1, A2, A3, A4 or A5 is 1,4-phenylene or 1,3-dioxane-2,5-diyl, for example. Z1, Z2, Z3 and Z4 are independently a single bond or C1-4 alkylene, for example. Y1 is fluorine, for example, m, n and p are independently 0 or 1, and 1?m+n+p?3.

Abstract: Provided are a liquid crystal composition containing, as a first component, a polymerizable compound represented by general formula (I): (Z11)m11-M11-(L11-M12)n11-COO-(M13-L12)n12-M14-(Z12)m12??(I) and a liquid crystal display element using the liquid crystal composition.

Abstract: The present invention relates to an optical switch element, comprising a liquid-crystalline medium for the temperature-dependent regulation of radiant energy flow. The invention furthermore relates to the use of the optical switch element for the regulation of radiant energy flow between interior spaces and the environment and for the regulation of the temperature of interior spaces. The invention furthermore relates to a liquid-crystalline medium, characterised in that it comprises 5-95% of a compound of the formula (I), in particular for use in the optical switch elements according to the invention.

Abstract: A liquid crystal compound and a liquid crystal medium are described. The liquid crystal compound is stable to heat and light and has a large dielectric anisotropy and a large optical anisotropy. The liquid crystal medium has a wide temperature range of liquid crystal phase, a large optical anisotropy and a large dielectric anisotropy, and exhibits an optically isotropic liquid crystal phase. The liquid crystal compound has 4 or 5 benzene rings, one of which is a chlorofluorobenzene ring. The liquid crystal medium is characterized in containing the liquid crystal compound and a chiral dopant and exhibiting an optically isotropic liquid crystal phase.

Abstract: A liquid crystal compound having a large refractive index anisotropy, a large dielectric anisotropy, and a low melting point, and a liquid crystal medium having a liquid crystal phase over a wide temperature range, a large refractive index anisotropy, a large dielectric anisotropy, and having an optically isotropic liquid crystal phase, are provided. The present invention is a liquid crystal compound having a chlorobenzene ring, and a liquid crystal medium characterized by containing the liquid crystal compound and a chiral reagent, and exhibiting an optically isotropic liquid crystal phase.

Abstract: The present invention relates to dielectrically positive liquid-crystalline media comprising one or more compounds of the formula I in which the parameters have the meaning indicated in the specification, and optionally one or more compounds selected from the group of the compounds of the formulae II and III in which the parameters have the meaning indicated in the specification, and optionally one or more compounds of the formula IV in which the parameters have the meaning indicated in the specification, and to liquid-crystal displays containing these media, especially to active-matrix displays and in particular to TN, IPS and FFS displays.

Abstract: An object of the present invention is to obtain a polymer-stabilized liquid crystal composition which can suppress dependency of a driving voltage on a temperature by decreasing the driving voltage. To a low-molecular liquid crystal compound, a chiral compound, and a specific acrylate and a polymerizable liquid crystal compound as polymerizable acrylate compounds are added, to prepare a polymer-stabilized liquid crystal composition. By subjecting the polymer-stabilized liquid crystal composition to ultraviolet exposure while maintaining a desired alignment state to form a polymer chain in a liquid crystal phase, a polymer-stabilized liquid crystal display device containing a low-molecular liquid crystal in a stabilized alignment state is obtained.

Abstract: The invention is to provide a liquid crystal composition satisfying at least one of characteristics such as a high maximum temperature of a nematic phase, a low minimum temperature of the nematic phase, a small viscosity, a suitable optical anisotropy, a large negative dielectric anisotropy, a large specific resistance, a high stability to ultraviolet light and heat, or a liquid crystal composition having a suitable balance regarding at least two of the characteristics; and an AM device having a short response time, a large voltage holding ratio, a large contrast ratio, a long service life and so forth; wherein a liquid crystal composition has a negative dielectric anisotropy and contains a specific compound having a large negative dielectric anisotropy as a first component and a specific two-ring compound having a large optical anisotropy and a low viscosity as a second component, and a liquid crystal display device contains the composition.

Abstract: A nematic phase liquid crystal compound with negative dielectric constant has a structure represented by wherein R1 represents a hydrogen atom or linear alkyl having 1 to 8 carbon atoms or linear alkenyl having 1-8 carbon atoms, or an alkoxy or alykenoxy formed by substituting one or nonadjacent two CH2 in the linear alkyl or alkenyl with oxygen atom, wherein 0 to 4 hydrogen atoms of R1 group can be substituted with fluorine; R2 represents a hydrogen atom or linear alkyl having 1 to 8 carbon atoms, or R2 represents a linear fluoroalkyl having 1 to 8 carbon atoms, in which group 1 to 4 hydrogens can be substituted with fluorine atoms; A represents a benzene ring or 1,4-cyclohexane ring, if A is a benzene ring 0 to 4 hydrogen atoms on the benzene ring may be substituted with fluorine; n=1 to 2, and m=0 to 2.

Abstract: The invention relates to a liquid-crystalline medium having negative dielectric anisotropy which comprises at least one compound of the formula I in which R1, R1* and a have the meanings indicated in Claim 1, and to the use thereof for an active-matrix display, in particular based on the VA, PS-VA, PALC, FFS or IPS effect.

Abstract: In an exemplary embodiment of the present invention, the content ratio of polar and neutral compounds in a liquid crystal layer is controlled, or a coupling agent that is well adapted to those compounds is used as a material for a sealant, thereby stably maintaining the display quality of the liquid crystal display even at low temperatures.

Abstract: The liquid crystal composition has a negative dielectric anisotropy, and contains a specific bicyclic compound having a large optical anisotropy and negative dielectric anisotropy as a first component and a specific tricyclic compound having a large dielectric anisotropy as a second component, and may contain a specific compound having a small viscosity as a third component, a specific compound having a large dielectric anisotropy and a small viscosity as a fourth component and a specific compound having a large dielectric anisotropy as a fifth component, and the liquid crystal display device includes the composition.

Abstract: The present invention relates to dielectrically positive liquid-crystalline media comprising a dielectrically neutral or slightly positive component, component A, comprising one or more dielectrically neutral or slightly positive compounds of the formula I in which the parameters have the meaning indicated in the specification, and a dielectrically positive component, component B, comprising one or more dielectrically positive compounds, and optionally a second dielectrically neutral component, component C, and to liquid-crystal displays containing these media, especially active-matrix displays and in particular TN, IPS and FFS displays.

Abstract: The instant invention relates to dielectrically positive nematic media comprising one or more compounds of formula I and one or more compounds of formulae II and III and optionally one or more compounds of formulae IV and V and liquid crystal devices comprising these media and especially to fast switching electro-optical devices.

Abstract: Provided is a polymerizable compound with large solubility in a liquid crystal composition and high reactivity irradiated by ultraviolet in the longer wavelength range. Provided is a liquid crystal composition that satisfies at least one of characteristics such as high maximum temperature of a nematic phase, low minimum temperature of a nematic phase, small viscosity, suitable optical anisotropy, large negative dielectric anisotropy, large specific resistance, high stability to ultraviolet light and high stability to heat, or that is suitably balanced between at least two of the characteristics.

Abstract: The instant invention relates to mesogenic media exhibiting a blue phase, comprising two or more components selected from the following components, components A to C, component A comprising one or more compounds selected from the group of compounds of formula I-T component B consisting of one or more compounds selected from the group of compounds of formula I-N component C consisting of one or more compounds selected from the group of compounds of formula I-E wherein the parameters are as specified in the text, preferably stabilized by a polymer, and their use in electro-optical light modulation elements and their respective use in displays, as well as to such displays.

Abstract: The invention provides a liquid crystal compound that has a large negative dielectric anisotropy (??) and also has at least one of characteristics such as the stability to heat, light or the like, a high clearing point, a suitable refractive index anisotropy (?n), a large negative dielectric anisotropy (??) and an excellent compatibility with other liquid crystal compounds. An excellent effect in which especially the value of the dielectric anisotropy (??) is increased negatively is achieved by use of the compound having two moieties of 1) a tetrahydropyran ring and and thus the effect is utilized.

Abstract: Isomannide-based compounds having chiral properties are provided, in addition to liquid crystal compositions and polymer networks derived therefrom.

Abstract: The invention is to provide a new liquid crystal compound having a high clearing point, a good compatibility with other compounds, a small viscosity, and a high stability to heat, light and so forth; compound (1) is provided: R1?CF2?nR2??(1) wherein, for example, R1 is alkyl having 4 to 10 carbons or —(CH2)2—CH?CH2, R2 is alkyl having 2 to 10 carbons, n is 8, and R1 and R2 are not allowed to be straight-chain alkyl having an identical number of carbons.

Abstract: The instant invention relates to liquid crystal media comprising one or more bimesogenic compounds, one or more chiral dopants and one or more additives, liquid crystal displays comprising these media, in particular displays exploiting the flexoelectric effect and to a method of improving the response time of such displays.

Abstract: The invention is to provide a liquid crystal composition that satisfies at least one of characteristics such as a high maximum temperature of a nematic phase, a low minimum temperature of a nematic phase, a small viscosity, a suitable optical anisotropy, a large negative dielectric anisotropy, a large specific resistance, a high stability to ultraviolet light and a high stability to heat, or that is suitably balanced between at least two of the characteristics; and is to provide a AM device that has a short response time, a large voltage holding ratio, a large contrast ratio, a long service life and so forth, wherein the liquid crystal composition includes a specific compound having a large negative dielectric anisotropy and a low minimum temperature as a first component and a specific compound having a large negative dielectric anisotropy, and the liquid crystal display device contains this composition.

Abstract: A liquid crystal composition that satisfies at least one characteristic, such as, high maximum temperature of a nematic phase, low minimum temperature of a nematic phase, small viscosity, suitable optical anisotropy, large dielectric anisotropy, large specific resistance, large elastic constant, high stability to ultraviolet light and high stability to heat, or that is suitably balanced between at least two of the characteristics; and provides an AM device that has short response time, large voltage holding ratio, large contrast ratio, long service life and so forth. A liquid crystal composition is provided that has a nematic phase and includes a specific three-ring compound having a large dielectric anisotropy as a first component, a specific four-ring compound having a high maximum temperature and a large dielectric anisotropy as a second component, and a liquid crystal display device containing the composition.

Abstract: The present invention provides a liquid-crystalline polymer composition comprising: 100 parts by weight of a liquid-crystalline polymer and 1-150 parts by weight of the total weight of talc particles (A) and talc particles (B), wherein talc particles (A) have an aspect ratio of 3.1-5.0 and a median particle diameter of 5-100 ?m; and talc particles (B) have an aspect ratio of 1.0-3.0 and a median particle diameter of 5-100 ?m; wherein the weight ratio of talc particles (A)/talc particles (B) is from 1/9 to 9/1. The liquid-crystalline polymer composition according to the present invention exhibits improved molding flowability without impairing mechanical properties.

Abstract: The invention is to provide a liquid crystal composition that satisfies at least one of characteristics such as a high maximum temperature of a nematic phase, a low minimum temperature of a nematic phase, a small viscosity, a large optical anisotropy, a large dielectric anisotropy, a large specific resistance, a high stability to ultraviolet light and a high stability to heat, or that is suitably balanced regarding at least two of the characteristics. The invention is to provide an AM device that has a short response time, a large voltage holding ratio, a large contrast ratio, a long service life and so forth. The invention is a liquid crystal composition that has a nematic phase and includes a specific four-ring compound having a high maximum temperature and a large optical anisotropy as a first component, and a specific four-ring compound having a large dielectric anisotropy as a second component, and is a liquid crystal display device containing this composition.

Abstract: Disclosed are a liquid-crystalline medium of negative dielectric anisotropy based on a mixture of polar compounds, which contains at least one compound of formula IA and at least one compound of formulae IB, IC and/or ID and the use thereof for an active-matrix display, in particular based on the ECB, PALC, FFS or IPS effect.

Abstract: The subject is to provide a liquid crystal composition that satisfies at least one of characteristics such as a high maximum temperature of the nematic phase, a low minimum temperature of the nematic phase, a small viscosity, a suitable optical anisotropy, a large negative dielectric anisotropy, a large specific resistance, a high stability to ultraviolet light and a high stability to heat, or that is suitably balanced regarding at least two of the characteristics. The subject is also to provide the AM device that has a short response time, a large voltage holding ratio, a large contrast ratio, a long service life, and so forth. The invention provides a liquid crystal composition having a negatively dielectric anisotropy containing a specific compound having a negatively large dielectric anisotropy as a first component, and a specific compound having a negatively large dielectric anisotropy as a second component, and provides a liquid crystal display device containing this composition.

Abstract: A novel liquid crystalline carbonate and the mixture containing the same: wherein R3 is an alkyl (H2n+1Cn) or an alkenyl (H2n?1Cn) group, each of 1 to 12 carbon atoms, the ring A is laterally unsubstituted benzene or pyridine or pyrimidine or trans-substituted cyclohexane ring, symbol r is 0 to 2; the lateral substituents: X2, X3, X4 and X5 in the benzene rings represent independently hydrogen or fluorine or chlorine atoms, X1 is hydrogen or fluorine atom and simultaneously at least one of the substituents: X2, X3 and X4 is fluorine or chlorine atoms, Y is an alkyl or an alkyloxy or an alkenyl or an aikenyloxy group, each of 1 to 12 carbon atoms or hydrogen or fluorine or chlorine atom or NCS group are described.

Abstract: The subject is to provide a liquid crystal composition that satisfies at least one characteristic of characteristics such as a high maximum temperature of a nematic phase, a low minimum temperature of a nematic phase, a small viscosity, a suitable optical anisotropy, a negatively large dielectric anisotropy, a large specific resistance, a high stability to ultraviolet light and a high stability to heat, or that is suitably balanced regarding two characteristics thereof. The subject is to provide an AM device that has a short response time, a large voltage holding ratio, a large contrast ratio, a long service life and so forth. The invention provides a liquid crystal composition having a negative dielectric anisotropy that includes a specific compound having 1-pyran-2,5-dyil as a first component, and a specific compound having a negatively large dielectric anisotropy as a second component , and provides a liquid crystal display device containing the composition.

Abstract: The present invention relates to a liquid-crystalline medium having high twist, to the use thereof for electro-optical purposes, and to displays containing this medium.

Abstract: A liquid crystal composition which satisfies at least one property selected from the properties including a high upper-limit temperature of a nematic phase, a low lower-limit temperature of a nematic phase, a low viscosity, high optical anisotropy, high positive dielectric anisotropy, a high specific resistance, high stability toward ultraviolet ray and high stability toward heat or has a proper balance between at least two properties selected from the aforementioned properties is described. And the liquid crystal composition which comprises a specific tetracyclic compound that enables the production of a nematic phase having a high upper-limit temperature and has high dielectric anisotropy as a first component and a specific compound having high positive dielectric anisotropy as a second component, and which has positive dielectric anisotropy; and a liquid crystal display element comprising the composition.

Abstract: The invention provides a liquid crystal composition having an optically isotropic liquid crystal phase used in an element driven in a state of an optically isotropic liquid crystal phase, which comprises a compound 1 having the clearing point T1 and a compound 2 having the clearing point T2, and which has the clearing point Tx, wherein the liquid crystal composition comprises 10 to 80 wt % of compound 1 and 20 to 90 wt % of compound 2, and wherein the clearing point T1, the clearing point T2 and the clearing point Tx of the liquid crystal composition satisfy the following conditions: T1>T2 T1?Tx?100° C.

Abstract: The invention is to provide a liquid crystal composition that satisfies at least one of characteristics such as a high maximum temperature of a nematic phase, a low minimum temperature of a nematic phase, a small viscosity, a suitable optical anisotropy, a large negative dielectric anisotropy, a large specific resistance, a high stability to ultraviolet light and a high stability to heat, or that is suitably balanced regarding at least two of the characteristics, wherein the liquid crystal composition has negative dielectric anisotropy and includes a specific compound having a large negative dielectric anisotropy as a first component, a specific compound containing a pyran ring and having a large negative dielectric anisotropy as a second component, a specific compound having a small viscosity as a third component, and a specific compound having a large negative dielectric anisotropy as a fourth component, and the liquid crystal display device contains this composition.

Abstract: A liquid crystal compound and a liquid crystal medium are described. The liquid crystal compound is stable to heat and light and has a large dielectric anisotropy and a large optical anisotropy. The liquid crystal medium has a wide temperature range of liquid crystal phase, a large optical anisotropy and a large dielectric anisotropy, and exhibits an optically isotropic liquid crystal phase. The liquid crystal compound has 4 or 5 benzene rings, one of which is a chlorofluorobenzene ring. The liquid crystal medium is characterized in containing the liquid crystal compound and a chiral dopant and exhibiting an optically isotropic liquid crystal phase.

Abstract: The invention relates to a liquid-crystalline medium which comprises at least one compound of the formula I, in which R1, R1*, ring A have the meanings indicated in Claim 1, and to the use thereof for an active-matrix display, in particular based on the VA, PSA, PS-VA, PALC, FFS or IPS effect.

Abstract: The invention relates to liquid-crystalline mixtures comprising at least one compound of the formula I, in which X, L1, L2, L3, L4 and alkenyl have the meanings indicated in claim 1, in order to increase the pretilt at the polyimide surface, and to liquid-crystalline media comprising one or more compounds of the formula I in electro-optical liquid-crystal displays and in LC lenses.

Abstract: A liquid crystal composition that satisfies at least one of characteristics such as high maximum temperature of a nematic phase, low minimum temperature of a nematic phase, small viscosity, large optical anisotropy, large positive dielectric anisotropy, large specific resistance, high stability to ultraviolet light and high stability to heat, or that is suitably balanced between at least two of the characteristics is provided. An AM device that has short response time, large voltage holding ratio, large contrast ratio, long service life and so forth is provided. The liquid crystal composition has positive dielectric anisotropy and includes a specific four-ring compound having a high maximum temperature of a nematic phase and a large dielectric anisotropy as a first component, a specific four-ring compound having a large positive dielectric anisotropy as a second component, and a specific four-ring compound having a high maximum temperature of a nematic phase as a third component.

Abstract: The invention is to provide a liquid crystal composition that satisfies at least one of characteristics such as a wide temperature range of nematic phase, a small viscosity, a suitable optical anisotropy, a large negative dielectric anisotropy, a large specific resistance, high stability to ultraviolet light and high stability to heat, or that is suitably balanced regarding at least two of the characteristics; and is to provide a AM device that has a short response time, a large voltage holding ratio, a large contrast ratio, a long service life and so forth. The liquid crystal composition having a negative dielectric anisotropy may include a two-ring compound having a large negative dielectric anisotropy and at least three fluorines or chlorines at the lateral positions as a first component; and a specific compound having a large negative dielectric anisotropy as a second component. The liquid crystal display device contains this composition.