The invention relates to a liquid crystal compound having the structure of formula I wherein R is selected from the group consisting of H and alkyl or alkoxy groups of 1 to 12 carbon atoms in which one or more H are unsubstituted or substituted with halogen; A.sub.1 is selected from the group consisting of a single bond or a 1,4-phenylene group in which each H in the 1,4-phenylene group is independently substituted by one or more halogen atoms; L.sub.1 and L.sub.2 are each independently selected from H or halogen; Z.sub.1 is a single bond or —(CH.sub.2).sub.2—. The compound has advantages of low rotational viscosity, large dielectric anisotropy, good mutual solubility and stability, which can be added to LC composition to reduce the driving voltage of the display. Thus, the novel compound has prosperous applications in LCD industry.

##STR00001##

The present invention relates to an LC medium comprising two or more polymerizable compounds, at least one of which contains a substituent comprising a tertiary OH group, to its use for optical, electro-optical and electronic purposes, in particular in LC displays, especially in LC displays of the PSA (polymer sustained alignment) or SA (self-aligning) mode, to an LC display of the PSA or SA mode comprising the LC medium, and to a process of manufacturing the LC display using the LC medium, especially an energy-saving LC display and energy-saving LC display production process.

The present invention relates to a liquid crystal (LC) display of the FFS type comprising a liquid crystal medium with negative dielectric anisotropy and a di- or multireactive polymerizable compound, and an alignment layer inducing planar alignment in the LC medium.

The present invention belongs to the technical field of liquid crystal materials, and in particular relates to a liquid crystal composition and a liquid crystal display element or liquid crystal display containing the liquid crystal composition. The liquid crystal composition of the present invention is characterized in that the liquid crystal composition comprises more than or equal to 30% of a compound represented by Formula I, and also comprises one or more compounds represented by Formula II and one or more compounds represented by Formula III. The liquid crystal composition of the present invention has a high refractive index, a high clearing point and also a low rotational viscosity, and is mainly used for the display of a projector with a relatively high working temperature and a low cell thickness.

##STR00001##

The invention relates to a light modulation element comprising a cholesteric liquid crystalline medium sandwiched between two substrates, each provided with an electrode structure, wherein at least one of the substrates is additionally provided with an alignment layer which is provided with a photoresist pattern consisting of periodic substantially parallel stripes. The invention is further related to a method of production of said light modulation element and to the use of said light modulation element in various types of optical and electro-optical devices, such as electro-optical displays, liquid crystal displays (LCDs), non-linear optic (NLO) devices, and optical information storage devices.

There is provided a liquid crystal composition which enables a significant reduction in crystallization temperature as compared with addition of a homolog while having a similar skeleton structure, which has an excellent compatibility, and which enables an increase in the absolute value of negative dielectric anisotropy (Δ∈). The liquid crystal composition contains two or more compounds which each have two to four ring structures between two side chains. At least one of the ring structures is a 2,3-difluorobenzene skeleton. The two side chains are bonded to different ring structures. The positions of the 2,3-difluorobenzene skeletons are different from each other, and the number of the ring structures are the same as each other.

The present invention relates to the technical field of liquid crystal displays, and particularly relates to a liquid crystal composition containing a 2-methyl-3,4,5-trifluorobenzene liquid crystal compound and use thereof, wherein the liquid crystal composition of the present invention comprises, in percentages by weight, 1-50% of one or more compounds represented by general formula I and 10-70% of one or more compounds represented by general formula II, and may further comprise 0-30% of compounds represented by general formula III and/or 6-45% of one or more compounds represented by general formulas IV to XIII The liquid crystal composition provided by the present invention has a low rotational viscosity and a large elastic constant, is presented as having a shorter response time, and can significantly improve the display effect of a liquid crystal display when applied to TN, IPS and FFS mode displays.

A liquid-crystalline medium having a nematic phase, a dielectric anisotropy of 0.5 or more and a ratio of the dielectric constant perpendicular to the director (∈.sub.⊥) to the dielectric anisotropy (Δ∈), i.e. (∈.sub.⊥/Δ∈), of 2.0 or less and comprises one or more compounds of formula I

##STR00001##

wherein the parameters have the meaning given in the text.

An electro-optical display containing such a medium, particularly in an active-matrix display based on the IPS or FFS effect. Methods for using of the compounds of formula I for improvement of the transmission and/or response times of a liquid-crystalline medium which comprises one or more additional mesogenic compounds.

The invention relates to a liquid-crystalline medium, in particular based on a mixture of polar compounds, and to the use thereof for an active-matrix display, in particular based on the VA, PSA, PS-VA, PA-VA, PALC, FFS, PS-FFS, IPS or PS-IPS effect.

It is an object of the present invention to provide a liquid crystal composition having positive Δ∈, having a liquid crystal phase in a wide temperature range, having high solubility at low temperatures, having high ODF process compatibility, having a high specific resistance and voltage holding ratio, and being insensitive to heat and light. In order to achieve this object, there is provided a liquid crystal composition containing at least one compound represented by the following general formula (i) and at least one compound represented by the following general formula (ii). ##STR00001## (wherein R.sup.i1 denotes an alkyl group having 2 to 5 carbon atoms) ##STR00002## (wherein R.sup.ii1 and R.sup.ii2 independently denote an alkyl group having 1 to 5 carbon atoms or an alkenyl group having 2 to 5 carbon atoms, and X.sup.ii1 and X.sup.ii2 independently denote a hydrogen atom or a fluorine atom)