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##

A grating is provided. The grating includes a first substrate and a second substrate opposite the first substrate, a plurality of first transparent electrodes arranged at equal intervals along a surface of the first substrate and between the first substrate and the second substrate, and a plurality of second transparent electrodes each arranged along a surface of the second substrate and opposite to a respective one of the plurality of first transparent electrodes, and a liquid crystal mixture layer arranged between each pair of the first transparent electrodes and respective second transparent electrodes, wherein a liquid crystal mixture in the liquid crystal mixture layer is switchable between a smectic phase and a cholesteric phase such that the liquid crystal mixture is transparent in the smectic phase and black in the cholesteric phase.

A grating is provided. The grating includes a first substrate and a second substrate opposite the first substrate, a plurality of first transparent electrodes arranged at equal intervals along a surface of the first substrate and between the first substrate and the second substrate, and a plurality of second transparent electrodes each arranged along a surface of the second substrate and opposite to a respective one of the plurality of first transparent electrodes, and a liquid crystal mixture layer arranged between each pair of the first transparent electrodes and respective second transparent electrodes, wherein a liquid crystal mixture in the liquid crystal mixture layer is switchable between a smectic phase and a cholesteric phase such that the liquid crystal mixture is transparent in the smectic phase and black in the cholesteric phase.

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.

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.

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, in particular based on a mixture of polar compounds, having compounds of formulae Y, CY, PY and/or LY, and compounds of formula S1 and/or S2:

##STR00001##

A liquid-crystalline medium, in particular based on a mixture of polar compounds, having compounds of formulae Y, CY, PY and/or LY, and compounds of formula S1 and/or S2:

##STR00001##

The compounds of the formula I, and a liquid-crystalline medium, preferably having a nematic phase and negative dielectric anisotropy, which comprises a) one or more compounds of the formula I ##STR00001## and b) one or more compounds of the formulae II-1 to II-4, ##STR00002##
in which the parameters have the meanings defined herein, are suitable for use in an electro-optical display, particularly in an active-matrix display based on the VA, ECB, PALC, FFS or IPS effect.