Electro-optical liquid crystal display

Electro-optical liquid crystal display

• having a realignment layer for realigning the liquid crystals whose field has a component parallel to the liquid crystal layer sufficient for leading to in-plane switching,
• and which contains a liquid crystalline medium of positive dielectric anisotropy, characterized in that the medium comprises at least one compound of the formula Ia ##STR38## and at least one compound of formula Ib ##STR39## in which ##STR40## is in each case ##STR41## and R.sup.1 is H, an alkyl or alkenyl radical having 1 to 15 carbon atoms which is unsubstituted, monosubstituted by CN or CF.sub.3 or at least monosubstituted by halogen, where one or more CH.sub.2 groups in these radicals may also, in each case independently of one another, be replaced by --O--, --S--, --CO--, --CO--O--, --O--CO-- or --O--CO-- in such a way, that O-atoms are not linked directly to one another,
• and at lease one compound of formula II ##STR42## in which L.sup.3 and L.sup.4 are each H or F,
• R.sup.2 is as defined for R.sup.1, and
• A.sup.3 and A.sup.4 are each, independently of one another, a
• a) trans-1,4-cyclohexylene radical or 1,4-cyclohexenylene radical, in which, in addition, one or more non-adjacent CH.sub.2 groups may be replaced by --O-- and/or --S--,
• b) 1,4-phenylene radical, in which, in addition, one or two CH groups may be replaced by N,
• c) radical from the group consisting of 1,4-dicyclo(2,2,2)octylene, piperidine-1,4-diyl,naphthaline-2,6-diyl, decahydronaphthaline-2,6-diyl and 1,2,3,4-tetrahydronaphthaline-2,6-diyl,
• where the radicals (a) and (b) may be substituted by one or two fluorine atoms,
• Z.sup.3 and Z.sup.4 are each, independently of one another, --CO--O--, --O--CO--, --CH.sub.2 O, --OCH.sub.2 --, --CH.sub.2 CH.sub.2 --, --CH.dbd.CH.sub.2 --C.tbd.C--, or a single bond, or one of the radicals Z.sup.3 and Z.sup.4 is --(CH.sub.2).sub.4 -- or --CH.dbd.CH--CH.sub.2 CH.sub.2 --, and
• n is 0, 1 or 2.