The present invention relates to liquid-crystal (LC) media as defined in claim 1, having negative dielectric anisotropy and to the use thereof for optical, electro-optical and electronic purposes, in particular in LC displays.

A liquid crystal display device includes, in sequence, a backlight, a first substrate including a color filter layer, a liquid crystal layer containing a liquid crystal composition, and a second substrate. The liquid crystal composition contains a liquid crystal compound having a phenyl group and a conjugated bond group. The phenyl group has a halogen atom substituted for at least one hydrogen atom. The conjugated bond group is conjugated with the phenyl group to form a continuous conjugated system.

The present invention relates to a liquid crystal (LC) medium comprising a compound of formula I

##STR00001## and one or more compounds selected from the group of compounds of the formulae IIA, IIB, IIC and IID,

##STR00002## as defined in claim 1, and to the use thereof for optical, electro-optical and electronic purposes, in particular in LC displays, especially in IPS, FFS, VA or PS-VA displays.

The present invention relates to a liquid crystal (LC) medium comprising a compound of formula I

##STR00001## and one or more compounds of formula II

##STR00002## as defined in claim 1, and to the use thereof for optical, electro-optical and electronic purposes, in particular in LC displays, especially in IPS, FFS, VA or PS-VA displays.

The disclosure provides a liquid crystal device including a liquid crystal composition containing a dichroic dye (dye-containing liquid crystal composition) that is in a light transmissive state when no voltage is applied to the transparent electrode and in a light scattering state when voltage is applied. The liquid crystal composition exhibits a negative dielectric constant anisotropy. The haze value of the liquid crystal device is 10% or less when no voltage is applied at 25° C., and the haze value is 50% or more when a rectangular wave voltage (AC 50 V, 60 Hz) is applied. The voltage holding ratio of the dye-containing liquid crystal composition is 60% or less at 25° C. The liquid crystal device provided by the disclosure is used as a component to provide a liquid crystal display apparatus, a light control apparatus, or a light transmitting apparatus with a high contrast.

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, SA-VA, IPS, PS-IPS, FFS, PS-FFS, UB-FFS or PS-UB-FFS effect.

A liquid crystal medium containing a) one or more compounds of formula I

##STR00001## b) one or more compounds of the formula IIBa

##STR00002## and c) one or more compounds of the formula IIDa

##STR00003## and the use thereof for optical, electro-optical and/or electronic purposes, in particular in LC displays, especially in IPS, FFS, VA or PS-VA displays.

A liquid-crystalline (LC) media having positive dielectric anisotropy and tliquid-crystal displays (LCDs) containing these media, especially to displays addressed by an active matrix and in particular to energy efficient LC displays of the TN, PS-TN, STN, TN-TFT, OCB, IPS, PS-IPS, FFS, HB-FFS, XB-FFS, PS-FFS, SA-HB-FFS, SA-XB-FFS, polymer stabilised SA-HB-FFS, polymer stabilised SA-XB-FFS, positive VA or positive PS-VA type.

The present invention belongs to the technical field of liquid crystal materials, and in particular relates to a liquid crystal composition with good frequency dependence and a liquid crystal display element or liquid crystal display containing the liquid crystal composition. The liquid crystal composition of the present invention comprises a compound represented by Formula I, a compound represented by Formula II and a compound represented by Formula III, wherein the mass percentage content of the compound represented by Formula I is not less than 30%. The liquid crystal composition provided by the present invention has an appropriate optical anisotropy, an appropriate dielectric anisotropy, especially a relatively low rotational viscosity, a good low-temperature mutual solubility and a good reliability, especially good frequency dependence.

##STR00001##

A liquid-crystal (LC) medium which is based on a mixture of polar compounds and is substantially dielectrically neutral, its use for optical, electro-optical and electronic purposes, in particular as optical retarder or optical compensator in LC displays, an optical retarder or optical compensator containing the LC medium, an optical, electrooptical or electronic device containing the optical retarder or optical compensator, and a process of manufacturing the optical retarder or optical compensator.