High-multiplexed supertwist liquid-crystal display

A liquid-crystal mixture consisting essentially of

• a) 15-50% by weight of a liquid-crystalline component A, which is one or more two- or there-ringed compounds having a dielectric anisotropy of more than +1.5;
• b) 0-25% by weight of a liquid-crystalline component B, which is one or more two- or three-ringed compounds having a dielectric anisotropy form -1.5 to +1.5;
• c) 40-80% by weight of a liquid-crystalline component T, which is three or more compounds having a tolan-4,4'-diyl structure element, and
• d) an optically active component D in such an amount that the ratio between the layer thickness (separation of the plane-parallel outer plates) and the natural pitch of the chiral nematic liquid-crystal mixture is from about 0.2 to 1,3,
• wherein the nematic liquid crystal mixture has a nematic phase range of at least 60.degree. C., a viscosity of not more than 25 mPas, a birefringence of at least 0.1950 and a dielectric anisotropy of at least +1, the dielectric anisotropies of the compounds and the parameters based on the nematic liquid-crystal mixture being based on a temperature of 20.degree. C.,
• and wherein component T comprises at least three compounds of formula I ##STR52## in which R.sup.1 is alkyl, alkoxy, alkenyl or alkenyloxy with 1 to 8 C atoms,
• L.sup.1 and L.sup.2 are each independently H or F,
• R.sup.2 is F, OCF.sub.3, alkyl or alkoxy with 1 to 8 C atoms,
• Z is a single bond, and
• p is 0 or 1.

A high-multiplexed supertwist liquid-crystal display containing

• two plane-parallel outer plates which, together with a frame, form a cell,
• a nematic liquid-crystal mixture of positive dielectric anisotropy which is present in the cell,
• electrode layers with superposed alignment layers on the insides of the outer plates which address each pixel by orthogonal row wave forms,
• pre-tilt angle between the longitudinal axis of the molecules at the surface of the outer plates and the outer plates of from about 1 degree to 30 degrees, and
• a twist angle of the liquid-crystal mixture in the cell from alignment layer to alignment layer with a value of between 100.degree. and 600.degree.,
• wherein the nematic liquid-crystal mixture consists essentially of
• a) 15-50% by weight of a liquid-crystalline component A, which is one or more two- or there-ringed compounds having a dielectric anisotropy of more than +1.5;
• b) 0-25% by weight of a liquid-crystalline component B, which is one or more two- or three-ringed compounds having a dielectric anisotropy form -1.5 to +1.5;
• c) 42-80% by weight of a liquid-crystalline component T, which is three or more compounds having a tolan-4,4'-diyl structure element, and
• d) an optically active component D in such an amount that the ratio between the layer thickness (separation of the plane-parallel outer plates) and the natural pitch of the chiral nematic liquid-crystal mixture is from about 0.2 to 1.3,
• wherein the nematic liquid crystal mixture has a nematic phase range of at least 60.degree. C., a viscosity of not more than 25 mPas, a birefringence of at least 0.1950 and a dielectric anisotropy of at least +1, the dielectric anisotropies of the compounds and the parameters based on the nematic liquid-crystal mixture being based on a temperature of 20.degree. C.,
• wherein component T comprises at least three compounds of formula I ##STR55## in which R.sup.1 is alkyl, alkoxy, alkenyl or alkenyloxy with 1 to 8 C atoms,
• L.sup.1 and L.sup.2 are each independently H or F,
• R.sup.2 is F, OCF.sub.3, alkyl or alkoxy with 1 to 8 C atoms,
• Z is a single bond, and
• p is 0 or 1, and wherein component B contains at least one compound of IV1 to IV4:
• ##STR56## in which R.sup.3 and R.sup.4 are alkyl, alkoxy, alkenyl or alkenyloxy with up to 12 carbon atoms,
• with the proviso that the mixture contains 5% to 15% by weight of at least one compound of formula IV6 ##STR57##