摘要:
The invention relates to a ferroelectric liquid-crystalline medium having improved low-temperature behavior, pronounced bistability and a phase sequence containing the phases isotropic, cholesteric, smectic A and chiral smectic C, comprising an achiral base material having a broad smectic C phase and at least one chiral dope which induces a spontaneous polarization of from 5 to 40 nCcm.sup.-2 in the achiral base material, characterized in that the medium has a chiral smectic C phase which is stable at least to -30.degree. C., and to the use thereof in electro-optical devices.
摘要:
The invention relates to an electro-optical liquid-crystal display having a realignment layer for realigning the liquid crystals, where the field thereof has a significant component parallel to the liquid-crystal layer, comprising a liquid-crystalline medium having negative dielectric anisotropy, where the medium comprises at least one mesogenic compound which contains a group of the formula A ##STR1## and at least one compound which contains a group of the formula B ##STR2##
摘要:
Compounds of the formula I,R.sup.1 --A.sup.1 --Z.sup.1 --A.sup.2 --[Z.sup.2 --A.sup.3 ].sub.m --R.sup.2 Iin which R.sup.1, R.sup.2, A.sup.1, A.sup.2, A.sup.3, Z.sup.1, Z.sup.2 and m have the meaning specified in patent claim 1, are suitable as components of smectic liquid-crystalline phases.
摘要:
The invention relates to an electro-optical liquid-crystal display having a realignment layer for realigning the liquid crystals whose field has a significant component parallel to the liquid-crystal layer and which contains a liquid-crystalline medium of positive dielectric anisotropy, where the medium comprises at least one mesogenic compound containing a 3,4,5-trifluorophenyl group and/or comprises at least one mesogenic compound [lacuna] a structural unit of the formula 2 ##STR1## in which A is O or CH,Z is --COO-- or a single bondL.sup.1 is F or, if A is O, is alternatively H, andL.sup.2 is H or F.
摘要:
The invention relates to an electro-optical liquid-crystal display having a realignment layer for realigning the liquid crystals whose field has a significant component parallel to the liquid-crystal layer and which contains a liquid-crystalline medium of positive dielectric anisotropy, where the medium comprises at least one mesogenic compound containing a 3,4,5-trifluorophenyl group and/or comprises at least one mesogenic compound [lacuna] a structural unit of the formula 2 ##STR1## in which A is O or CH,z is --COO-- or a single bondL.sup.1 is F or, if A is O, is alternatively H, andL.sup.2 is H or F.
摘要:
The invention relates to improved STN displays of which the nematic liquid crystalline medium comprises compounds of formulae I1, I2, II1 and/or III1 ##STR1## wherein R.sup.3 and R.sup.4 are each independently alkyl with 1 to 8 C atoms, ##STR2## wherein R.sup.1 is alkyl or alkoxy with 1 to 8 C atoms, ##STR3## wherein R2 is oxaalkyl, alkenyl with up to 8 C atoms.