Disclosed are a liquid crystal (LC) medium containing a polymerisable compound, a process for its preparation, its use for optical, electro-optical and electronic purposes, in particular in LC displays, especially in an LC display of the polymer sustained alignment (PSA) type, and to an LC display, especially a PSA display.

A liquid crystal display device, including: a display substrate including a first base substrate, a switching device disposed on the first base substrate, a color filter layer disposed on the switching device, and a first electrode disposed on the color filter layer; a counter display substrate including a second base substrate and a second electrode disposed on the second base substrate and facing the first electrode, wherein the counter display substrate is disposed separately from and facing the display substrate; a liquid crystal layer disposed between the display substrate and the counter display substrate, wherein the liquid crystal layer includes at least one first liquid crystal compound represented by Formula 1 and at least one second liquid crystal compound represented by Formula 2; and a light-shielding spacer disposed between the display substrate and the counter display substrate and maintaining a thickness of the liquid crystal layer:

##STR00001##

wherein in Formula 1 and Formula 2, each of R.sub.11—*,

##STR00002##

R.sub.12—*, L.sub.11-*, L.sub.12-*, L.sub.13-*, L.sub.14-*, R.sub.21—*, *-L.sub.21-*, m, n, i, j, o is same as defined in the specification.

Compounds of the formula I, ##STR00001##
in which Y.sup.1 denotes —O— or —CH.sub.2—, and the groups R.sup.1, L.sup.1 to L.sup.6 and X.sup.1 have the meanings indicated in claim 1. A process for the preparation thereof, and liquid-crystalline media comprising at least one compound of the formula I and electro-optical displays containing a liquid-crystalline medium this type. The compounds of the formula I include, as structural element, a combination of a 1,4-substituted cyclohexene ring besides a dioxane or tetrahydropyran ring and a substituted biphenyl group.

A liquid-crystalline medium containing one or more compounds of formula IA, ##STR00001##
and the use thereof in an active-matrix display, in particular in a VA, IPS, U-IPS, FFS, UB-FFS, SA-VA, SA-FFS, PS-VA, PS-OCB, PS-IPS, PS-FFS, PS-UB-FFS, PS-posi-VA, PS-TN, polymer stabilised SA-VA or polymer stabilised SA-FFS display.

Polyfluorinated additives for use as components in liquid-crystal mixtures. Liquid-crystal mixtures which comprise these compounds. And liquid-crystal displays based on these liquid-crystal mixtures.

A liquid-crystalline medium, preferably having a nematic phase and dielectric anisotropy of 0.5 or more, which comprises one or more compounds of each of formulae T and L ##STR00001##
in which the parameters have the meanings given in the claims and in the text. 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. Also, the compounds of formulae T and L and their use for the improvement of the transmission and/or response times of a liquid-crystalline medium which comprises one or more additional mesogenic compounds.

Disclosed are a liquid crystal composition and a liquid crystal display device. The liquid crystal composition comprises at least one compound of general formula I, at least one compound of general formula II, at least one compound of general formula III, and at least one compound of general formula IV. By compounding the four compounds, the composition can have advantages of a wide temperature range of nematic phase, a low viscosity and a low threshold voltage, and the liquid crystal display element can have a short response time and great power saving performance.

The invention relates to a compound of formula I, ##STR00001##
wherein R.sup.11, R.sup.21, A.sup.11, A, Z, X.sup.11, X.sup.21, Y.sup.11, Y.sup.12, Sp.sup.11, Sp.sup.21, o and p have one of the meanings as given in claim 1. The invention further relates to method of production of a compound of formula I, to the use of said compounds in LC media and to LC media comprising one or more compounds of formula I. Further, the invention relates to a method of production of such LC media, to the use of such media in LC devices, and to LC device comprising a LC medium according to the present invention. The present invention further relates to a process for the fabrication such liquid crystal display and to the use of the liquid crystal mixtures according to the invention for the fabrication of such liquid crystal display.

A double layer liquid crystal device comprises a first and a second layer with orthogonal or crossed alignment of the liquid crystal phase of the two layers, in which the first and second layer have first and second alignment aids comprised of a polymerized or polymerizable molecular compound. The layers are aligned by UV photoalignment and vertical self-alignment by the aid of suitable additives.

The present invention relates to liquid-crystal (LC) media having negative dielectric anisotropy comprising one or more compounds of formula I

##STR00001##

and one, two, three or more compounds of formula III

##STR00002##

as defined in claim 1, and to the use of the LC media for optical, electro-optical and electronic purposes, in particular useful to enable energy-saving LC displays of the VA, IPS or FFS type.