A composition having a high n, a wide temperature range of a liquid crystal phase, low viscosity, good solubility at a low temperature, high resistivity, a high voltage holding ratio, and stability against heat and light; a liquid crystal composition containing the composition, the liquid crystal composition having a good lens effect and good chemical stability; a liquid crystal display device including the liquid crystal composition; and a liquid crystal lens including the liquid crystal composition. The liquid crystal composition contains one or two or more compounds represented by general formula (i) and one or two or more compounds represented by general formula (ii).

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.

Described herein are liquid crystal compositions and derivative mixtures thereof that can allow for the adjustment of their refractive indices by the application of an electric field. In addition, selectively dimmable reverse-mode polymer dispersed liquid crystal (PDLC) elements and devices using the aforementioned compositions are also described, which are transparent when no voltage is applied and opaque when a voltage is applied.

Disclosed is a liquid crystal composition comprising one or more compounds represented by formula I and/or formula II and one or more compounds represented by formula III: ##STR00001##
wherein the definition of each substituent is given. The composition involved in the present invention has a low viscosity .sub.1, a high clearing point Tni and a large optical anisotropy n, and can realize a rapid response of liquid crystal display.

Disclosed are a liquid crystal composition and a liquid crystal display device. The liquid crystal composition comprises at least one compound of general formula I, at least one compound of general formula II, at least one compound of general formula III, and at least one compound of general formula IV. By compounding the four compounds, the composition can have advantages of a wide temperature range of nematic phase, a low viscosity and a low threshold voltage, and the liquid crystal display element can have a short response time and great power saving performance.

Liquid-crystalline media comprising one or more compounds of formula T

##STR00001##

as defined in claim 1, and high-frequency components comprising these media, especially microwave components for high-frequency devices, such as devices for shifting the phase of microwaves, tunable filters, tunable metamaterial structures, and electronic beam steering antennas, e.g. phased array antennas.

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.

There is provided a liquid crystal composition which has favorable characteristics and excellent characteristic balance as a material for an element used for phase control of an electromagnetic wave signal with a frequency of 1 MHz to 400 THz. A liquid crystal composition which contains at least one compound selected from the group consisting of compounds represented by Formula (1), and is used for phase control of an electromagnetic wave signal with a frequency of 1 MHz to 400 THz:

##STR00001##

As a material to be used in a device used for phase control of an electromagnetic wave signal with a frequency of 1 MHz to 400 THz, a liquid crystal composition having a high maximum temperature of a nematic phase, a low minimum temperature of the nematic phase, large optical anisotropy, small dielectric loss, and thermal stability in a frequency range used for phase control and having good balance between characteristics is required. A liquid crystal composition used for phase control of an electromagnetic wave signal with any frequency of 1 MHz to 400 THz containing at least one compound selected from a group consisting of compounds represented by formula (1) and at least one compound selected from a group consisting of compounds represented by formula (2).

##STR00001##

A liquid crystal composite that contains a liquid crystal composition satisfying at least one of characteristics such as high maximum temperature, low minimum temperature, small viscosity, large optical anisotropy and large positive dielectric anisotropy, and that is suitable for dimming, or having a suitable balance regarding at least two of the characteristics; and a liquid crystal dimming device having the liquid crystal composite. The liquid crystal composite contains a polymer and a liquid crystal composition containing a specific compound having large positive dielectric anisotropy. The liquid crystal composite may further contain a specific compound having high maximum temperature or low minimum temperature; or a specific compound having large negative dielectric anisotropy.