The present invention relates to liquid-crystalline media comprising one or more chiral compounds and one or more compounds selected from the group of compounds of formulae I, II and III, ##STR00001##
in which the parameters have the meaning indicated in claim 1, and to components comprising these media for high-frequency technology, in particular phase shifters and microwave array antennas.

The present invention relates to polymer stabilized nematic liquid crystal microlenses. The microlenses can be made from a nematic liquid crystal, a chiral dopant, a reactive monomer, and a photoinitiator. The microlenses can be prepared by spin coating a liquid crystal mixture onto an array including a nickel transmission electron microscope grid. The focal length of the microlens array can be tuned electrically.

The instant invention relates to liquid crystalline media comprising a chiral component, component A, consisting of one or more chiral compounds, optionally, a bimesogenic component, component B, consisting of one or more bimesogenic compounds, a liquid crystalline component, component C, consisting of one or more liquid crystalline, respectively mesogenic compounds, and a reactive mesogenic component, component D, comprising, one or more reactive mesogenic compounds,
as defined in claim 1, to their stabilization by polymerization and to the polymer-stabilised liquid crystal materials, as well as to liquid crystal displays comprising these liquid crystal media, respectively these stabilized materials, especially to USH-displays and in particular to active matrix displays and, last not least, to the processes of preparation of the respective composite systems and of the displays comprising these systems.

The instant invention relates to mesogenic media exhibiting a blue phase, comprising one or both components selected from the two following components, components A and B, component A, comprising one or more compounds selected from the group of compounds of formula I-M, ##STR00001##
and component B, consisting of one or more compounds selected from the group of compounds of formula I-U, ##STR00002##
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.

The invention relates to a reactive mesogen (RM) formulation comprising a conductive additive, to a polymer film obtained thereof, and the use of the RM formulation and polymer film in optical or electrooptical components or devices, like optical retardation films for liquid crystal displays (LCDs).

A liquid crystal composition is described, containing a chiral agent and achiral component T containing at least one compound 1 having an unsubstituted or methyl group-substituted dioxane ring and having at least one —COO— or —CF.sub.2O— as a connecting group, and exhibiting an optically isotropic liquid crystal phase.

A light valve that is operable in and electrically switchable between an optically clear and transparent state and an opaque state, wherein one or more polymerisable mesogenic compounds provided in a layer containing a liquid-crystalline medium that comprises one or more mesogenic compounds, one or more chiral compounds, one or more dichroic dyes and the one or more polymerisable mesogenic compounds are subjected to photopolymerisation. Further, a liquid-crystalline medium used in the method, a light valve obtained or respectively obtainable by carrying out the method, and the use of the light valve in mobile devices.

A liquid crystal cell includes substrates defining a gap and electrodes having one of (i) an in-plane geometry generating an electric field parallel with the substrates and (ii) a top-down geometry generating an electric field across the gap between the two spaced apart substrates. A liquid crystal material disposed in the gap between the substrates comprises a chiral nematic material formed by a mixture of: 1-(4-cyanobiphenyl-4′-yl)-6-(4-cyanobiphenyl-4′-yloxy)hexane (CB6OCB) or α,ω-bis(4,4-cyanobiphenyl)nonane (CB9CB) dimeric liquid crystal material; at least one additional dimeric liquid crystal material; and a chiral dopant. The liquid crystal material within an operational range of electric field applied by the electrodes exhibits a heliconical state with an oblique angle helicoid director whose helicoid axis is oriented parallel with the electric field and whose helicoid pitch is sized to provide diffraction or Bragg reflection of light in a spectral range of interest impinging on one of the substrates of the liquid crystal cell.

The present invention relates to liquid crystal media comprising polymerisable mesogenic compounds with a bent shape, and to electro-optical displays comprising these media as light modulation media. In particular the electro-optical displays according to the present invention are displays, which are operated at a temperature, at which the liquid crystal modulation media are in an optically isotropic phase, preferably in a blue phase.

Disclosed herein is a light emitting device and method of manufacturing such a device comprised of a series of photopolymerizable, chiral liquid crystalline layers that can be solvent cast on a substrate. The mixture of chiral materials in each successive layer may be blended in such a way that each layer has the same chiral pitch. Further the chiral materials in each layer may also be blended so that the ordinary and extraordinary refractive indices in each layer match the other layers such that the complete assembly of layers will optically function as a single relatively thick layer of chiral liquid crystal. The chiral nematic material in each layer can spontaneously adopt a helical structure with a helical pitch. The light emitting layers of the light emitting device can further comprise electroluminescent material that emits light into the band edge light propagation modes of the photonic crystal.