A liquid crystal display device includes a first substrate, a second substrate facing the first substrate, and a liquid crystal layer interposed between the first substrate and the second substrate. The liquid crystal layer includes liquid crystal molecules having a negative dielectric anisotropy, a response speed of about 4.0 ms or less, and a rotational viscosity of about 47 mPa.Math.S to about 75 mPa.Math.S.

The present invention provides a liquid crystal display device with reduced power consumption as well as reduced flicker. The liquid crystal display device is one in a transverse electric field mode, including: paired substrates; a photo-alignment film disposed on at least one of the substrates; a horizontal alignment liquid crystal layer disposed between the substrates; and pixels arranged in a matrix form, the liquid crystal layer containing liquid crystal molecules with a bicyclohexyl skeleton and liquid crystal molecules with a difluorobenzene skeleton, the liquid crystal layer having negative anisotropy of dielectric constant, one of the substrates including TFTs disposed in the respective pixels, the TFTs each including a semiconductor layer that contains an oxide semiconductor, the liquid crystal display device having a frame rate of lower than 50 Hz.

The invention relates to a liquid-crystalline medium based on a mixture of polar compounds which contains at least one compound of the formula I, ##STR00001##
and at least one additional compound, and to the use of the LC mixtures for an active- or passive matrix addressed displays, in particular based on the VA, PSA, PS-VA, IPS, FFS, PS-IPS, PS-FFS technology, preferably in optical displays for the self-aligning VA mode.

To provide a liquid crystal compound having high polymerization reactivity, a high conversion ratio and high solubility in a liquid crystal composition, a polymerizable composition containing the compound, a liquid crystal composite prepared using the composition, and a liquid crystal display device including the composite. The liquid crystal display device prepared using the polymerizable composition containing the compound represented by formula (1): ##STR00001##
wherein, in formula (1), P.sup.1 to P.sup.6 are a polymerizable group; S.sup.1 to S.sup.6 are a single bond, alkylene or the like; a1, a3 and a4 are an integer from 0 to 4, a2 is an integer from 1 to 4; ring A.sup.1 to ring A.sup.4 are a divalent group derived from benzene, naphthalene, anthracene, pyrimidine, pyridine or the like; Z.sup.1 to Z.sup.3 are a single bond, alkylene or the like, and at least one of Z.sup.1, Z.sup.2 and Z.sup.3 is CC; and b1 is 0 or 1.

The present invention relates to a liquid-crystalline medium based on a mixture of polar compounds having negative dielectric anisotropy (), which is distinguished by the fact that it has a value for the ratio .sub.1/n.sup.2 in the range 6-45 with a clearing point of >60 C. and a of 2.3. Media of this type are particularly suitable for electro-optical displays having active-matrix addressing based on the ECB, PA LCD, FFS or IPS effect.

The subject is to show a liquid crystal composition in which the homeotropic alignment of liquid crystal molecules can be achieved by the action of a polymer, and a liquid crystal display device including this composition.

The means concerns a nematic liquid crystal composition that has positive dielectric anisotropy and that includes a specific liquid crystal compound having a large positive dielectric anisotropy as a first component and a polar compound having a polymerizable group as a first additive, and the composition may include a specific liquid crystal compound having a high maximum temperature or a small viscosity as a second component, a specific liquid crystal compound having a positive dielectric anisotropy as a third component, a specific liquid crystal compound having negative dielectric anisotropy as a fourth component, and a polymerizable compound as a second additive, and concerns a liquid crystal display device including the composition.

The purpose of the present invention is to provide: elements, in particular, a display element and an optical element, which are obtained by controlling orientation of liquid crystals in a liquid crystal bulk without using a liquid crystal orientation film; and/or a photoreactive liquid crystal composition for manufacturing the elements. The present invention provides: a photoreactive liquid crystal composition comprising (A) a photoreactive polymer liquid crystal which includes a photoreactive side chain in which at least one type of reaction selected from the group consisting of (A-1) photocrosslinking and (A-2) photoisomerization occurs, and (B) a low molecular weight liquid crystal; and an optical element or display element which is formed having a liquid crystal cell including the composition.

Provided is a compound having an effect on preventing photolysis of a liquid crystal composition and having a high solubility in the liquid crystal composition, a liquid crystal composition containing the compound and a liquid crystal display device including the composition. The compound is represented by formula (1), the liquid crystal composition contains the compound, and the liquid crystal display device uses the composition.

##STR00001##

In formula (1), R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are independently hydrogen or alkyl having 1 to 4 carbons; R.sup.5 is hydrogen, hydroxy, oxy radical, alkyl having 1 to 10 carbons or alkoxy having 1 to 10 carbons; ring A.sup.1 is 1,4-cyclohexylene, 1,4-cyclohexenylene or the like; Z.sup.1 and Z.sup.2 are independently a single bond or alkylene having 1 to 10 carbons; and a is 0, 1, 2 or 3.

A liquid crystal display device includes a first substrate, a second substrate facing the first substrate, and a liquid crystal layer interposed between the first substrate and the second substrate. The liquid crystal layer includes liquid crystal molecules having a negative dielectric anisotropy, a response speed of about 4.0 ms or less, and a rotational viscosity of about 47 mPa.Math.S to about 75 mPa.Math.S.

The present invention relates to liquid-crystalline media comprising one or more compounds selected from the group of compounds of formulae I, II and III,

##STR00001##

in which the parameters R.sup.1-R.sup.3, Z.sup.21, Z.sup.31, Z.sup.32 and rings A.sup.11, A.sup.12, A.sup.13, A.sup.21, A.sup.22, A.sup.31, and A.sup.32 are as defined herein, and to components comprising these media for high-frequency technology, in particular phase shifters and microwave array antennas.