A compound having a maximum absorption in a wavelength range of 350 nm to 550 nm that functions as a dichroic dye is provided. In particular, a compound represented by formula (1) is provided. In the compound of formula (1), R.sup.1 represents a hydrogen atom or the like; R.sup.2 represents a hydrogen atom or the like; R.sup.3 represents a hydrogen atom or the like; Z represents —CO— or the like; and Y represents a group of formula (Y1). In the group of formula (Y1), * represents a bonding site with N, or a group of formula (Y2); and in the group of formula (Y2), * represents a bonding site with N; P.sup.1 and P.sup.2 each independently represent —S— or the like; and Q.sup.1 and Q.sup.2 each independently represent ═N— or the like.

##STR00001##

The invention provides a liquid crystal compound satisfying at least one of physical properties such as a high stability to heat or light, a high clearing point (or a high maximum temperature), a low minimum temperature of a liquid crystal phase, a small viscosity, a suitable optical anisotropy, a small dielectric anisotropy, a suitable elastic constant and a good compatibility with other liquid crystal compounds, a liquid crystal composition including this compound, and a liquid crystal display device containing this composition. The invention provdes a compound represented by formula (1):

##STR00001##

where R.sup.1 and R.sup.2 is alkyl having 1 to 20 carbons or the like; one of L.sup.1 and L.sup.2 is both hydrogens, and the other is both fluorines; Z.sup.1 and Z.sup.2 are independently a single bond, —COO—, —OCO—, —OCH.sub.2—, —CH.sub.2O—, —CF.sub.2O—, —OCF.sub.2—, —CH.sub.2CH.sub.2—, —CH═CH—, —C≡C— or the like.

The disclosure provides a liquid crystal display (LCD) panel, a manufacturing method thereof, and an LCD device. The LCD panel adopts a structure with multiple electrodes and dual-frequency liquid crystals. When a temperature of the LCD panel is low (below 0° C.), the LCD panel is driven at high frequency, so that it emits more heat. Therefore, a working temperature of the LCD panel is increased without adding a heating element. LCD devices using such LCD panels have wide working temperature ranges, and are well suited to be used outdoors.

Provided is a liquid crystal composition satisfying at least one of characteristics such as a high maximum temperature, a low minimum temperature, small viscosity, large optical anisotropy and large dielectric anisotropy, or has a suitable balance regarding at least two of the characteristics, and an AM device including the composition. The liquid crystal composition may contain a specific compound having large negative dielectric anisotropy as a first component, a specific compound having a high maximum temperature or small viscosity 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.

To provide 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 heat, or having a suitable balance regarding at least two of the characteristics; and an AM device having characteristics such as short response time, a large voltage holding ratio, low threshold voltage, a large contrast ratio and long service life. The composition has negative dielectric anisotropy and contains a specific compound having large negative dielectric anisotropy as a first component, a specific compound having small viscosity as a second component, and may contain a specific compound having high maximum temperature or small viscosity as a third component, a specific compound having negative dielectric anisotropy as a fourth component, or a specific compound having a polymerizable group as an additive component.

The present invention relates to liquid crystal media comprising polymerisable mesogenic compounds with a bent shape, and to electro-optical displays comprising these media as light modulation media. In particular the electro-optical displays according to the present invention are displays, which are operated at a temperature, at which the liquid crystal modulation media are in an optically isotropic phase, preferably in a blue phase.

The invention relates to a polymerisable LC medium with negative optical dispersion, a polymer film with negative optical dispersion obtainable from such a medium, and the use of the polymerisable LC medium and polymer film in optical, electro optical, electronic, semiconducting or luminescent components or devices.

The subject is to provide liquid crystal display device having a short response time, a large voltage holding ratio, a low threshold voltage, a large contrast ratio, a long service life and a small flicker rate.

The liquid crystal display device having a liquid crystal alignment film formed on the opposing surfaces of a pair of substrates, and a liquid crystal composition therebetween, wherein the liquid crystal alignment film includes a polymer derived from a polyamic acid having a photodegradable group, and the liquid crystal composition includes at least one compound represented by formula (1) as a first component:

##STR00001##

R.sup.1 is alkyl having 1 to 12 carbons or the like; ring A is 1,4-cyclohexylene, 1,4-phenylene or the like; Z.sup.1 is a single bond or the like; X.sup.1 and X.sup.2 are hydrogen or fluorine; Y.sup.1 is fluorine or the like; and a is 1, 2, 3 or 4.

An optical film, a polarizing plate, and an image display device, each having an optically anisotropic layer obtained by curing a polymerizable liquid crystal composition including a polymerizable liquid crystal compound (LCC) having forward wavelength dispersion and a monofunctional compound, and immobilizing an alignment state of the polymerizable LCC. The number a.sub.1 of atoms of the polymerizable LCC and the number a.sub.2 of atoms of the monofunctional compound satisfy a relationship of Expression (1): 0.2<a.sub.2/a.sub.1<0.55; the number b.sub.1 of the rings B.sup.1 contained in the polymerizable LCC and the total number b.sub.2 of the aromatic rings Ar and the rings B.sup.2 contained in the monofunctional compound satisfy a relationship of Expression (2): b.sub.2=b.sub.1×0.5 or b.sub.2=(b.sub.1+1)×0.5.

The invention relates to a polymerisable LC medium with flat optical dispersion, a polymer film with flat optical dispersion obtainable from such a medium, and the use of the polymerisable LC medium and polymer film in optical, electro optical, electronic, semiconducting or luminescent components or devices.