Rolic Ag

Hoffmann-la Roche Inc.

Niopic Moscow Research and Production Association

Alexander V Ivashchenko

Martin Schadt

Nina I Chernova

Marina V Loseva

Arnold Z Rabinovich

Vladimir G Chigrinov

Leonid A Beresnev

Victor V Titov

Evgeniv P Pozhidaev

Dmitry I Dergachev

Boris I Ostrovskiv

Richard Buchecker

Olga S Petrashevich

Evgeniy P Pozhidaev

A liquid crystal display cell comprising a chiral ferroelectric smectic liquid crystal layer whose helix structure is influenced by the action of an electric field such that its optical anisotropy alters; a pair of transparent plates between which the liquid crystal is disposed and which have a surface structure for aligning the molecule of the liquid crystal and are provided with electrodes to produce an electric field therein; and one polarizer each before and after the liquid crystal, such that a ratio d/p of the thickness d of the liquid crystal layer to the pitch height p of the helical twisting is greater than 5, the smectic tilt angle &thgr; between 0.39 radians and 0.87 radians and the product d&middot;&thgr; &middot;&Dgr;n&middot;1/&lgr; (phase factor) of the thickness d, the square of the tilt angle &thgr;&deg;, the value of the birefringence &Dgr;n and the reciprocal of the wavelength &lgr; of light bending is greater than 0.45 radians .

Distorted helix ferroelectric liquid crystal cell

A liquid crystal display cell comprising a chiral ferroelectric smectic liquid crystal layer whose helix structure is influenced by the action of an electric field such that its optical anisotropy alters; a pair of transparent plates between which the liquid crystal is disposed and which have a surface structure for aligning the molecule of the liquid crystal and are provided with electrodes to produce an electric field therein; and one polariser each before and after the liquid crystal: such ratio d/p of the thickness d of the liquid crystal layer to the pitch height p of the helical twisting is greater than 5, the smectic tilt angle .theta..sub.o is being between 22.5 .degree. and 50.degree. and the product d..theta..sub.o.sup.2..DELTA.n.1/.lambda. (phase factor) of the thickness d, the square of the tilt angle .theta..sub.o, the value of the birefringence .DELTA.n and the reciprocal of the wavelength .lambda. of light bedding is greater than 0.45 .mu.m.

Ferroelectric liquid crystal cell

A liquid crystal display cell comprising a chiral ferroelectric smectic liquid crystal layer whose helix structure is influenced by the action of an electric field such that its optical anisotropy alters; a pair of transparent plates between which the liquid crystal is disposed and which have a surface structure for aligning the molecule of the liquid crystal and are provided with electrodes to produce an electric field therein; and one polariser each before and after the liquid crystal: such ratio d/p of the thickness d of the liquid crystal layer to the pitch height p of the helical twisting is greater than 5, the smectic tilt angle .theta..sub.o is being between 22.5.degree. and 50.degree. and the product d.multidot..theta..sub.o.sup.2 .multidot..DELTA.n.multidot.l/.lambda. (phase factor) of the thickness d, the square of the tilt angle .theta..sub.o, the value of the birefringence .DELTA.n and the reciprocal of the wavelength .lambda. of light bedding is greater than 0.45 .mu.m.

Optically active compounds of the formula ##STR1## wherein rings A, B and C each independently are unsubstituted or each are 1,4-phenylene substituted with at least one of halogen-, cyano-, methyl- or methoxy in which optionally 1 CH group or 2 CH groups is/are replaced by nitrogen; R.sup.1 is a radical of an optically active terpene alcohol after cleavage of the hydroxy group or a group --(CH.sub.2).sub.m --C*HX.sup.1 --R.sup.3 ; R.sup.2 is a radical of an optically active terpene alcohol after cleavage of the hydroxy group or a group --(CH.sub.2).sub.n --C*HX.sup.2 --R.sup.4 ; m and n each independently stand for the number O or 1: C* denotes a chiral carbon atom; X.sup.1 and X.sup.2 each independently are fluorine, chlorine, cyano, methyl or methoxy; R.sup.3 and R.sup.4 each independently denote a group R, phenyl or phenyl substituted with R, with the proviso that R.sup.3 is different from X.sup.1 and R.sup.4 is different from X.sup.2 ; R is an alkyl group in which optionally one methylene group is replaced by oxygen and/or optionally one group CH--CH is replaced by a group C.dbd.C; with the proviso that R.sup.1 and R.sup.2 are not simultaneously 2-alkyl when rings A, B and C together are p-terphenyl, as well as liquid crystalline mixtures and their use for electro-optical purposes.

Liquid crystalline mixtures having a chiral tilted smectic phase

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Moscow, Russia

Alexander V Ivashchenko