The invention relates to a liquid-crystalline medium having a nematic phase comprising one or more compounds of formula X ##STR00001##
wherein the parameters have the meaning given in the text, to the use thereof in an electro-optical display, particularly in an active-matrix display based on the IPS or FFS effect, to displays of this type which contain a liquid-crystalline medium of this type and to the use of the compounds of formula X for improvement of the transmission and/or response times of a liquid-crystalline medium which comprises one or more additional mesogenic compounds, as well as to the compounds of formula X.

The disclosure discusses chiral dopants for liquid-crystalline materials. Chiral dopants can be bioreachable compounds, i.e. compounds produced from microbes through fermentation. Chiral dopants can also include bioreachable materials that are further modified by chemical synthetic steps. Chiral dopants as discussed herein can include biomolecules such as glycyrrhetinic acid (1), S-naringenin (2), shikimic acid (3), alpha-phellandrene (4), betulin (5), malic acid (6), valencene (7), or nootkatone (8), and any stereoisomers or chemically modified derivatives thereof. The disclosure further shows optical properties of such compounds in a liquid-crystalline material.

The invention relates to a polymerizable LC material comprising one or more reactive mesogenic compounds, one or more chiral compounds and one or more compounds of formula I,

##STR00001##

wherein the individual radicals have one of the meaning as given in the claims. Furthermore, the present invention relates also to a method for its preparation, a polymer film with improved thermal and UV stability obtainable from a corresponding polymerizable LC material, to a method of preparation of such polymer film, and to the use of such polymer film and said polymerizable LC material in optical, electro-optical, decorative or security devices.

Provided are a decorative material including a pressure sensitive adhesive layer and a cholesteric liquid crystal layer in contact with the pressure sensitive adhesive layer, in which, in the cholesteric liquid crystal layer, a content of a compound having a molecular weight of 10,000 or less per unit volume of the cholesteric liquid crystal layer is less than 44 mg/cm.sup.3; and applications thereof.

A liquid-crystalline medium which comprises at least one compound selected from the group of compounds of the formulae IA to IH,

##STR00001##

in which Z.sup.1 denotes a single bond, —CH.sub.2CH.sub.2—, —CH═CH—, —CH.sub.2O—, —OCH.sub.2—, —CF.sub.2O—, —OCF.sub.2—, —COO—, —OCO—, —C.sub.2F.sub.4—, —(CH.sub.2).sub.4—, —CHFCHF—, —CF.sub.2CH.sub.2—, —CH.sub.2CF.sub.2—, —C≡C—, —CF═CF—, —CH═CHCHO— or —CH.sub.2CF.sub.2O—,
and the use thereof for an active-matrix display, in particular based on the VA, PSA, PS-VA, PALC, FFS, PS-FFS, SA-VA, PS-IPS or IPS effect.

A liquid-crystalline medium which comprises at least one compound selected from the group of compounds of the formulae IA to IH,

##STR00001##

in which Z.sup.1 denotes a single bond, —CH.sub.2CH.sub.2—, —CH═CH—, —CH.sub.2O—, —OCH.sub.2—, —CF.sub.2O—, —OCF.sub.2—, —COO—, —OCO—, —C.sub.2F.sub.4—, —(CH.sub.2).sub.4—, —CHFCHF—, —CF.sub.2CH.sub.2—, —CH.sub.2CF.sub.2—, —C≡C—, —CF═CF—, —CH═CHCHO— or —CH.sub.2CF.sub.2O—,
and the use thereof for an active-matrix display, in particular based on the VA, PSA, PS-VA, PALC, FFS, PS-FFS, SA-VA, PS-IPS or IPS effect.

A lasing device includes an active layer comprising a cholesteric liquid crystal material and a laser dye, and a liquid crystal cell including spaced apart substrates defining a cell gap in which the active layer is disposed. The substrates include electrodes arranged to bias the active layer into an oblique helicoidal (Ch.sub.OH) state. At least one substrate of the liquid crystal cell is optically transparent for a lasing wavelength range of the device.

The present invention relates to liquid-crystalline (LC) media and to LC displays (LCDs) containing these media, in particular to LCDs of the twisted nematic (TN) mode, preferably to displays of the LCOS (LC on silicon) mode.

A fast flexoelectro-optic switching device containing bimesogen-doped and polymer-stabilized vertical standing helix (PSVSH) in a cholesteric liquid crystal. The PSVSH device exhibits a response time of less than 0.7 millisecond, high contrast and negligible hysteresis which is suitable for applications including blur-free displays, field-sequential color displays and active optical elements.

A fast flexoelectro-optic switching device containing bimesogen-doped and polymer-stabilized vertical standing helix (PSVSH) in a cholesteric liquid crystal. The PSVSH device exhibits a response time of less than 0.7 millisecond, high contrast and negligible hysteresis which is suitable for applications including blur-free displays, field-sequential color displays and active optical elements.