The invention relates to a liquid-crystalline medium having negative dielectric anisotropy comprising one or more compounds of formula I

##STR00001##

and
one or more compounds selected from the group of the compounds of the formulae IIA, IIB and IIC,

##STR00002##

wherein the groups and parameters have the meanings indicated in claim 1, to a guest-host liquid crystal medium derived therefrom comprising one or more dichroic dyes and the use of said medium in devices such as light shutters, switchable windows, switchable mirrors and guest-host displays. The invention further relates to devices containing the liquid crystalline medium according to the invention.

The invention relates to polyfluorinated additives for use as components in liquid-crystal mixtures, to liquid-crystal mixtures which comprise these compounds, and to liquid-crystal displays based on these mixtures.

Disclosed is a liquid crystal composition comprising one or more compounds represented by formula I, one or more compounds represented by formula II, and one or more compounds represented by formula III:

##STR00001##

The liquid crystal composition has simultaneously a lower rotary viscosity, a better photoelectric performance, a higher clearing point, a good low temperature performance, and less display defects. Further disclosed is a liquid crystal display element or device comprising the liquid crystal composition.

The present invention relates to a switching layer based on a liquid-crystalline mixture for use in an optical switching element. The invention also encompasses a switching element comprising the switching layer and a window element containing the switching element. The liquid crystalline mixture comprises a low-molecular liquid crystal component, a polymer component and a self-alignment additive for vertical alignment.

The disclosure is a liquid crystal compound represented by Formula (I),

##STR00001## wherein R.sup.1, R.sup.2, R.sup.3, ring A.sup.1, ring A.sup.2, ring A.sup.3, Z.sup.1, Z.sup.2, and n have definitions that are described in details herein. The liquid crystal compound represented by Formula (I) can be used to prepare a liquid crystal composition that has superior low-temperature storage.

A curved liquid crystal display includes a first substrate, a second substrate overlapping the first substrate, a liquid crystal layer positioned between the first substrate and the second substrate and including a plurality of liquid crystal molecules, and a lower protrusion positioned between the first substrate and the liquid crystal layer, the lower protrusion being formed from at least one among a first compound represented by Chemical Formula 1, a polymer obtained from the first compound, and a polymer of the first compound and a cross-linker.

Provided are a reactive mesogen that may improve display quality of a liquid crystal display, and a liquid crystal composition including the same. The reactive mesogen is represented by the following Formula:

BZ.sub.1.sub.b1XZ.sub.2.sub.b2Pa where X, Z1, Z2, B, and Pa are specified in the disclosure, and each of b1 and b2 is independently an integer between 0 to 6, inclusive.

The invention relates to a liquid-crystalline medium which comprises at least one compound of the formula I, ##STR00001## in which R.sup.1, R.sup.1*, Z.sup.1, Z.sup.2 and L.sup.1-3 have the meanings defined herein, and to the use thereof for an active-matrix display, in particular based on the VA, PSA, PS-VA, PALC, FFS, PS-FFS, PS-IPS or IPS effect.

The spontaneous orientation aid for a liquid crystal composition provides storage stability and allows liquid crystal molecules to be vertically aligned without a PI layer when added to a liquid crystal composition. The spontaneous orientation aid for a liquid crystal composition includes a compound having a partial structure represented by formula (i), particularly in which K.sup.i1 is represented by one of formula (K-1) to formula (K-11). When used in a liquid crystal composition, the spontaneous orientation aid can adsorb to substrates sandwiching a liquid crystal composition (liquid crystal layer) and keep the liquid crystal molecules aligned in a vertical direction. The spontaneous orientation aid makes it possible to align liquid crystal molecules without a PI layer (to induce vertical alignment of liquid crystal molecules under no applied voltage and to achieve horizontal alignment of the liquid crystal molecules under an applied voltage).

The present invention relates to a positive dielectric anisotropic liquid crystal composition comprising one or more compounds of formula I and one or more compounds of formula II, and a liquid crystal display device. The liquid crystal composition disclosed by the present invention has the characteristics of positive dielectric properties, a high charge retention ratio, a low rotary viscosity, a fast response time, and especially a high transmittance, and is suitable for manufacturing a TFT-LCD with a high transmittance and a fast response.

##STR00001##