摘要:
Nematic liquid crystal display device, in which the isocontrast curve has obtained a more symmetrical shape by combining two and four sub-pixels with twist angles which are smaller than 90 degrees, at which the sub-pixels are obtained by providing different orientation directions (11) in an orienting layer (8) by means of linearly polarized light. If a cholesteric nematic liquid crystal material is used, a sub-pixel may have a twist angle of more than 90 degrees, while pairs of sub-pixels then have twist angles of opposite twist sense, at which the sum of the absolute values of the twist angles is smaller than 180 degrees.
摘要:
Optically active compounds of the formula ##STR1## wherein m stands for the number 1 and R.sup.2 is an unsubstituted or halogen-substituted alkyl or alkenyl group in which optionally one methylene group is replaced by oxygen and/or optionally one methylene group is replaced by an ester group --COO-- or --OOC--; or m stands for the number 0 or 1 and R.sup.2 denotes a group of the formula ##STR2## R.sup.1 and R.sup.3 each independently represent an alkyl or alkenyl group in which optionally one methylene group is replaced by oxygen; Z.sup.1, Z.sup.2 and Z.sup.3 each independently are a single covalent bond, --CH.sub.2 O--, --OCH.sub.2 --, --CH.sub.2 CH.sub.2 --, --COO-- or --OOC--; n stands for the number 0 or 1; rings A.sup.1 and A.sup.2 each independently are unsubstituted or halogen, cyano and/or methyl-substituted 1,4-phenylene in which optionally 1 CH group or 2 CH groups is/are replaced by nitrogen; and C.sup.* denotes a chiral carbon atom; with the proviso that simultaneously R.sup.l does not are an alkyl group, m and n do not are the number 1, Z.sup.1 does not are the group --CH.sub.2 CH.sub.2 -- or --CH.sub.2 O-- and ring A.sup.1, Z.sup.2, ring A.sup.2 and R.sup.2 together do not are 4-(5-alkyl-2-pyrimidinyl)-phenyl, their preparation, liquid crystalline mixtures which contain these compounds and their use for electro-optical purposes.
摘要:
Compounds of the formula ##STR1## wherein R.sup.1 is alkyl or alkenyl; Z.sup.1 denotes a single covalent bond or --CH.sub.2 CH.sub.2 --; ring A represents unsubstituted or halogen- and/or methyl-substituted 1,4-phenylene; Z.sup.2 denotes a single covalent bond, oxygen or --CH.sub.2 O--; and R.sup.2 is an unsubstituted or halogen-substituted alkyl or alkenyl group,their preparation as well as liquid crystalline mixtures and their use for electro-optical purposes.
摘要:
A liquid crystal display with a liquid crystal layer enclosed by two parallel plates which carry electrodes and on top thereof a first layer system of several dielectric electrodes having refractive indices smaller than 2.2 and a thickness of the layers above the base layer, under 200 nm. The liquid crystal display is characterized by the following features with respect to the first carrier plate.the electrode has a thickness d.sub.e, within the range according to 0 0, n.sub.e =index of refraction of the electrode, nm=nanometer),the base layer has an index of refraction n.sub.b and a thickness d.sub.b, within the range according to 1.40.ltoreq.n.sub.b .ltoreq.1.50 and 20 nm.ltoreq.d.sub.b .ltoreq.50 nm or (m 300/n.sub.b -20) nm.ltoreq.d.sub.b .ltoreq.(m 300/n.sub.b +20) nm,the remaining layers of the first layer system have indices of refraction n.sub.i and a total thickness d.sub.s1-b according to 1.60.ltoreq.n.sub.i .ltoreq.1.70 and 20 nm.ltoreq.d.sub.s1-b
摘要:
This invention relates to a normally white super-twist nematic liquid crystal display device for multiplex operation, comprising a liquid crystal cell essentially comprising a liquid crystal layer (2), being sandwiched between a front and a rear substrate (3, 4), an at least partly reflective film (5, 13, 14, 15), arranged in proximity to said rear substrate (4), and a front optical stack, arranged on a viewer's side of the front substrate, the stack comprising one or more optical films, wherein the front optical stack consists solely of a polarizer (7) and an optional light scattering film (6).
摘要:
Optically active dopants of the formula ##STR1## wherein A represents an optically active group selected from 1,1'-binaphthyl-2,2'-diyl, --CHR.sup.1 --CHR.sup.2 -- or --CH(COOR.sub.3)--CH(COOR.sub.4)--; Z denotes a group --(CH.sub.2).sub.4 --, --O(CH.sub.2).sub.3 -- or the trans form of --OCH.sub.2 --CH.dbd.CH--; R is hydrogen, methyl, phenyl or cyclohexyl; R.sup.2 is methyl, phenyl or cyclohexyl; R.sup.3 and R.sup.4 denote alkyl; Y stands for --CO-- or --CH.sub.2 --; ring B represents 1,4-phenytene or trans-1,4-cyclohexylene; and R is hydrogen, alkyl, alkoxy or cyano,liquid crystalline mixtures which contain such dopants and their use for optical and electro-optical purposes.
摘要:
Compounds of the formula ##STR1## wherein n stands for the number 0 or 1; R.sup.1 denotes a group R.sup.3 or R.sup.3 --A.sup.3 --Z.sup.2 -- and R.sup.2 denotes a group R.sup.4 or R.sup.4 --A.sup.4 --Z.sup.3 --; ring A.sup.1 is unsubstituted or halogen-, cyano- and/or methylsubstituted 1,4-phenylene in which optionally 1 CH group or 2 CH groups is/are replaced by nitrogen; A.sup.3 A.sup.4 and ring A.sup.2 each independently represent unsubstituted or halogen-, cyano- and/or methyl- -substituted 1,4-phenylene in which optionally 1 CH group or 2 CH groups is/are replaced by nitrogen or trans-1,4-cyclohexylene, trans-1,3-dioxane-2,5-diyl, 1-cyano-trans-1,4-cyclohexylene, bicyclo[2.2.2]octane- -1,4-diyl, naphthalene-2,6-diyl, tetralin-2,6-diyl or trans-decalin-2,6- diyl; Z.sup.1, Z.sup.2 and Z.sup.3 each independently are a single covalent bond, --COO--, --OOC--, --CH.sub.2 O--, --OCH.sub.2 --, --CH.sub.2 CH.sub.2 --, --C.vertline.C--, --(CH.sub.2).sub.3 O--, --O(CH.sub.2).sub.3 --, --(CH.sub.2).sub.4 -- or the trans form of --CH.dbd.CH-- CH.sub.2 O-- or --OCH.sub.2 --CH.dbd.CH--; R.sup.3 and R.sup.4 each independently denote halogen, cyano, --NCS, --CF.sub.3, --OCF.sub.3 or alkyl in which optionally one >CH--CH C.dbd.C
摘要:
A liquid crystal display enclosing between two parallel plates a liquid crystal layer which can be switched between two optically different states. The plate surfaces facing each other each carry a matching layer on top of which are the electrodes. On top of the electrode is a first layer system with a dielectric layer and a topmost orientation layer. The refraction index n.sub.u of the substrata is smaller than the index n.sub.e of the electrode. The index of the matching layer has the following relationship: ##EQU1## The matching layer has a thickness d.sub.a, according to: ##EQU2## wherein .lambda.=550 nm, m=natural integer >0, and nm=nanometer, The electrode has a thickness d.sub.e, according to: d.sub.e .ltoreq.30 nm or ##EQU3##
摘要:
The present invention provides for improved brightness and reduced power consumption in transflective displays operating in transmissive mode. The invention is based on the inclusion of a depolarizing means (206) between the transflector (201) and the rear stack polarizer (202). The depolarizer (206) is arranged to selectively depolarize light originating from the backlight (203) and reflected by the transflector (201), without substantially affecting the light that is transmitted through the transflector. Thereby part of the reflected light is transmitted back through the rear stack polarizer (202) and can be recycled in the backlight (203). The invention is applicable to any transflective display having a transflector (201) that changes polarization of light originating from the backlight (203) upon reflection back towards the backlight (202).
摘要:
This invention relates to a liquid crystal display device, comprising at least one retardation film (4), a nematic liquid crystal layer (5), and a light reflecting RGB patterned cholesteric colour filter (6), for reflecting either essentially left-circular or right-circular polarised light, being characterised in that said liquid crystal layer (5) is a super twisted nematic liquid crystal layer having a twist angle in the interval 180-270 degrees, and in that the summed retardation R of the retardation film or retardation films and the liquid crystal layer is equal to approximately R=(3+2n)λ/4, where n=0,1,2,3.