The present invention relates to a liquid crystal display device. The liquid crystal display device of the present invention comprises a first substrate, a second substrate, and a liquid crystal composition disposed between said first substrate and said second substrate, wherein said first substrate and said second substrate are disposed in parallel and opposite to each other, with the distance between said first substrate and said second substrate being 2.5 m to 3.2 m; alignment layers are disposed on the sides of said first and second substrates that are close to said liquid crystal composition; and said alignment layers are provided with vertical alignment films that allow liquid crystal molecules in said liquid crystal composition to be arranged roughly perpendicular to said first or second substrate.

The present invention relates to a liquid crystal display device. The liquid crystal display device of the present invention comprises a first substrate, a second substrate, and a liquid crystal composition disposed between said first substrate and said second substrate, wherein said first substrate and said second substrate are disposed in parallel and opposite to each other; alignment layers are disposed on the sides of said first and second substrates that are close to said liquid crystal composition; and said alignment layers are provided with vertical alignment films that allow liquid crystal molecules in said liquid crystal composition to be arranged roughly perpendicular to said first and second substrates, with said liquid crystal molecules having a pretilt angle of 88.5 to 89.5.

A liquid crystal compound comprising a specific compound having a positive dielectric anisotropy as the first component, and a specific compound having a low viscosity as a second component. Further, the liquid crystal compound may contain a specific compound having a positive dielectric anisotropy as the third component, a specific compound having a maximum temperature or a low viscosity as the fourth component, or a specific compound having a negative dielectric anisotropy as the fifth component.

A liquid crystal composition having one or more compounds represented by formula I, one or more compounds represented by formula II and one or more compounds represented by formula III: ##STR00001##
The liquid crystal composition has a good stability against light and heat and a lower viscosity, and can achieve a wider refractive index and higher clearing point by the adjustment the ratio of the monomers. In particular, the liquid crystal composition has a higher light transmittance, allowing a display device to have a higher brightness or an energy saving 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 the liquid crystal composition having 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 has negative dielectric anisotropy and contains a specific compound having large negative dielectric anisotropy as a first component, a specific compound having low minimum temperature as a second component, and a specific compound having small viscosity as a third component, and the composition may contain a specific compound having high maximum temperature or small viscosity as a fourth component, a specific compound having negative dielectric anisotropy as a fifth component, or a specific compound having a polymerizable group as an additive component.

The present invention provides, by using a photo-alignment film, a liquid crystal display device in which a good voltage holding ratio is retained for a long period of time and occurrence of image sticking and stain in a display screen is prevented. The liquid crystal display device of the present invention includes an active matrix liquid crystal panel and a backlight, the liquid crystal panel including a liquid crystal layer, a pair of substrates that sandwich the liquid crystal layer in between, and an alignment film disposed on a liquid crystal layer side surface of each of the substrates, each alignment film being a photo-alignment film formed from a material that exhibits a photo-alignment characteristic and containing carboxyl groups on the liquid crystal layer side, the liquid crystal layer containing a liquid crystal material and a nitrobenzene derivative.

The present invention relates to a liquid-crystalline medium based on a mixture of polar compounds having negative dielectric anisotropy (), which is distinguished by the fact that it has a value for the ratio .sub.1/n.sup.2 in the range 6-45 with a clearing point of >60 C. and a of 2.3. Media of this type are particularly suitable for electro-optical displays having active-matrix addressing based on the ECB, PA LCD, FFS or IPS effect.

A liquid-crystalline medium containing one or more compounds of formula IA,

##STR00001##

and the use thereof in an active-matrix display, in particular in a VA, IPS, U-IPS, FFS, UB-FFS, SA-VA, SA-FFS, PS-VA, PS-OCB, PS-IPS, PS-FFS, PS-UB-FFS, PS-posi-VA, PS-TN, polymer stabilised SA-VA or polymer stabilised SA-FFS display.

The present invention provides a liquid crystal composition and a liquid crystal display device thereof. The liquid crystal composition comprises at least one compound of general formula I and at least one compound of general formula II. The liquid crystal composition has a larger vertical dielectric constant (.sub.), a larger ratio of the vertical dielectric constant to the absolute value of dielectric anisotropy (.sub./||), a larger K.sub.ave value and a higher transmittance while maintaining an appropriate clearing point, an appropriate optical anisotropy, and an appropriate absolute value of the dielectric anisotropy, such that the liquid crystal display device comprising the same has a better contrast, a faster response speed and a better transmittance while maintaining an appropriate range of operating temperature and an appropriate threshold voltage.

##STR00001##

Provided is a liquid crystal display device comprising a first substrate, a second substrate, and a liquid crystal composition disposed between said first substrate and said second substrate, wherein a surface of said first substrate in contact with said liquid crystal composition is provided with an alignment layer, while said second substrate has no alignment layer; and said liquid crystal composition comprises a liquid crystal compound, a self-aligning agent, and a polymerizable compound represented by Formula I,

##STR00001##