Provided are a compound represented by the following general formula (1) ##STR00001##
and a liquid crystal composition containing the compound, and a liquid crystal display device or a light control device having the liquid crystal composition. The compound represented by general formula (1) has both a large dichroic ratio and high solubility in the host liquid crystal. In addition, it has excellent chemical stability at a level usable as a device. Therefore, by using the compound represented by general formula (1) as a component of a GH-type liquid crystal composition, it is possible to provide a liquid crystal display device or a light control device with high contrast.

The present invention relates to liquid crystal (LC) media comprising one or more polymerisable compounds as further specified in the description or claims and a self-alignment additive for vertical alignment. The media are adapted for use in LC displays, especially in LC displays of the polymer-sustained alignment type.

The present invention relates to dibenzofuans and dibenzothiophenes thiophenes of formula I ##STR00001##
in which the occurring groups and parameters have the meanings as indicated in claim 1, to liquid-crystalline media comprising same and to high-frequency components comprising these media, especially microwave components for high-frequency devices, such as devices for shifting the phase of microwaves, in particular for microwave phased-array antennas.

A compound is represented by general formula (I), a liquid-crystal composition contains this compound, and devices are made using this liquid-crystal composition. Having a large refractive-index anisotropy Δn and a sufficiently high Tni, highly compatible with liquid-crystal compositions, and exhibiting a high dielectric anisotropy in the radio frequency range, the compound is a useful material for RF phase shifters, phased-array antennae, image recognition devices, distance meters, liquid-crystal displays, liquid-crystal lenses, and birefringent lenses for 3D image display, among other devices. ##STR00001##

A liquid crystal composition includes the following compounds: (in a range of 21.5 to 26.5 parts by weight) a compound represented by a first chemical formula, (in a range of 2.5 to 7.5 parts by weight) a compound represented by a second chemical formula, (in a range of 12.5 to 17.5 parts by weight) a compound represented by a third chemical formula, (in a range of 5.5 to 10.5 parts by weight) a compound represented by a fourth chemical formula, (in a range of 7.5 to 12.5 parts by weight) a compound represented by a fifth chemical formula, (in a range of 2 to 7 parts by weight) a compound represented by a sixth chemical formula, (in a range of 10.5 to 15.5 parts by weight) a compound represented by a seventh chemical formula, and (in a range of 13 to 18 parts by weight) an compound represented by an eighth chemical formula 8.

A compound that helps achieve a high voltage holding ratio (VHR) of a liquid crystal composition, a liquid crystal composition that contains this compound, and a liquid crystal display element made with this liquid crystal composition. More specifically, a compound represented by general formula (Y), which has polymerizable groups and polar group(s). A liquid crystal composition containing one or two or more compounds represented by general formula (Y), each of which has polymerizable groups and polar group(s). A liquid crystal display element made with a liquid crystal composition that contains one or two or more compounds represented by general formula (Y), each of which has polymerizable groups and polar group(s).

A LC lens and a liquid-crystal medium used in said LC lens, wherein the medium contains one or more compounds of each of formulae I and II ##STR00001##

A liquid crystal composition includes at least one compound of general formula I, at least one compound of general formula II and at least one compound of general formula III. The liquid crystal composition has a higher optical anisotropy, the relatively large elastic constants K.sub.11 and K.sub.33 while maintaining a relatively high clearing point, an appropriate dielectric anisotropy and a better low-temperature intersolubility. A liquid crystal display device which includes the liquid crystal composition has advantages of a fast response, a high contrast and a wide temperature range, thereby having a good display effect and a large range of applicability. ##STR00001##

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 certain compounds of formula X, as specified in the text.

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.