Disclosed are a liquid-crystalline medium which contains at least one compound of formula IA,

##STR00001##

and in addition at least one compound of formula CC-n-V and/or CC-V-V1,

##STR00002##

where the percentage proportion of the compound(s) of formula IA is greater than or equal to the percentage proportion of CC-n-V, and/or the percentage proportion of the compound(s) of formula IA is greater than the percentage proportion of CC-V-V1, where the percentage proportion is based on the liquid-crystalline medium,
and the use thereof in active-matrix displays, in particular based on the VA, PSA, PVA, PS-VA, SS-VA, SA-VA, PA-VA, PALC, FFS, PS-FFS, PS-IPS or IPS effect.

Provided are a liquid crystal composition satisfying at least one of characteristics such as high maximum temperature, low minimum temperature, small viscosity, suitable optical anisotropy, large negative dielectric anisotropy, large specific resistance, high stability to ultraviolet light and high stability to heat, or has a suitable balance regarding at least two of the characteristics; and an AM device having characteristics such as a short response time, a large voltage holding ratio, low threshold voltage, a large contrast ratio and a long service life. The liquid crystal composition may contain a specific compound having large negative dielectric anisotropy as a first component, a specific compound having high maximum temperature as a second component, a specific compound having negative dielectric anisotropy as a third component, or a specific compound having a polymerizable group as an additive component.

A liquid-crystalline medium, preferably having a nematic phase and exhibiting a dielectric anisotropy of 0.5 or more, which contains compounds of formula B and formula S ##STR00001## in which ##STR00002##
denotes ##STR00003##
denotes ##STR00004##
the use thereof in an electro-optical display, particularly in an active-matrix display based on the IPS or FFS effect, displays of this type which contain a liquid-crystalline medium of this type, and the use of the compounds of formula S for the improvement of the transmission and/or response times of a liquid-crystalline medium which contains one or more additional mesogenic compounds.

Provided is a liquid crystal compound containing 2,3,4-trisubstituted benzene, a liquid crystal composition thereof, and a liquid crystal display element or a liquid crystal display comprising the liquid crystal compound or the liquid crystal composition, wherein the liquid crystal composition has a lower viscosity, can achieve a quick response, and further has a moderate dielectric anisotropy , a moderate optical anisotropy n, and high stability to heat and light. The liquid crystal display element or liquid crystal display comprising the liquid crystal composition has the properties of a wider nematic phase temperature range, an appropriate birefringence anisotropy, a very high electrical resistivity, a good ultraviolet resistant property, a high charge retention rate, a low vapor pressure etc., and particularly, the liquid crystal compound or the liquid crystal composition has the advantage of a high light transmittance.

An object of the present invention is to provide a composition that realizes high n, has a wide liquid crystal phase temperature range, small viscosity, excellent low-temperature solubility, and high resistivity and voltage holding ratio, and is stable against heat and light, and to provide a liquid crystal composition having an excellent lens effect and excellent chemical stability using the composition, and a liquid crystal display device and a liquid crystal lens that use the liquid crystal composition. The present invention provides a liquid crystal composition that contains one or two or more compounds represented by general formula (i) and one or two or more compounds represented by general formula (ii), a liquid crystal display device using the liquid crystal composition, a liquid crystal lens using the liquid crystal composition, and a birefringence lens for stereoscopic image display using the liquid crystal composition.

The disclosure provides a liquid crystal composition having favorable characteristics and excellent characteristic balance as a material used for an element used for phase control of an electromagnetic wave signal having a frequency of 1 MHz to 400 THz. A liquid crystal composition which is used for phase control of an electromagnetic wave signal having a frequency of 1 MHz to 400 THz, and which includes a compound selected from the group represented by Formula (1),

##STR00001## in Formula (1), the ring A.sup.0 to the ring A.sup.4 are each independently 1,4-phenylene and the like; Z.sup.0 to Z.sup.3 are each independently a single bond or CF.sub.2O, where CF.sub.2O is one or less in Z.sup.0 to Z.sup.3; p is 0 or 1; and R.sup.1 is alkyl having 1 to 12 carbon atoms and the like, and R.sup.11 is CN and the like.

A liquid crystal composition that satisfies at least one of characteristics such as a high maximum temperature, a low minimum temperature, a small viscosity, a suitable optical anisotropy and a large negative dielectric anisotropy, or that has a suitable balance between at least two of these characteristics, and an AM device including this composition. The nematic liquid crystal composition includes a specific compound having a large negative dielectric anisotropy as a first component and a specific compound having a small viscosity as a second component, and may include a specific compound having a negative dielectric anisotropy as a third component, and a specific compound having a high maximum temperature or a small viscosity as a fourth component, or a specific compound having a polymerizable group as an additive.

The invention relates to a liquid crystal mixture characterised in that it comprises one or more photoreactive mesogens of formula I

##STR00001##

wherein the parameters and groups occurring are defined as indicated in claim 1, to a process for the fabrication of liquid crystal displays using these liquid crystal mixtures and to a liquid crystal display obtainable by this process. The invention further relates to new compounds of formula I.

A compound having the structure of general formula I is useful as a liquid crystal composition and as a photoelectric display device including the liquid crystal composition. The compound having the structure of general formula I is chemically and physically stable, and has higher clearing point, and both large dielectric anisotropy and large optical anisotropy at the same time. The compound having the structure of general formula I is well compatible with other liquid crystal compounds when applied in a liquid crystal composition, the composition has good stability especially in a low-temperature environment, the characteristic of fast response and a wide range of applicabilities, especially applicable to the IPS-type and TN-TFT-type liquid crystal display devices.

##STR00001##

The present invention relates to dielectrically positive liquid-crystalline media comprising one or more compounds of the formula I, ##STR00001##
and one or more compounds selected from the group of the compounds of the formulae II and III and/or IV, ##STR00002##
in which the parameters have the respective meanings indicated in the specification, and optionally one or more further dielectrically positive compounds and optionally one or more further dielectrically neutral compounds, and to liquid-crystal displays, especially active-matrix displays and in particular TN, IPS and FFS displays, containing these media.