Liquid crystal display
First Claim
1. A liquid crystal display comprisingan electrically switchable, dielectrically positive twisted nematic liquid crystal mixture layer between two substrates which together with a frame form a cell, said liquid crystal mixture is essentially based on superfluorinated liquid crystal compounds,two electrode layers, with alignment layers thereon, applied to said substrates, one of said electrode layers forms an active matrix of non-linear switching elements integrated with each picture element, and the other electrode layer is the counter electrode,said alignment layers are each an organic polymer layer which are essentially uniformly alignable by rubbing, said alignment layers resulting in an essential homogeneous surface alignment of the liquid crystal layer with a surface tilt angle, wherein said liquid crystal mixture comprises at least 30 wt. % of one or more compounds according to formula I ##STR23## wherein R is alkyl with up to 12 C atoms or alkyl with up to 12 C atoms wherein one or two non-adjacent CH2 -groups are each replaced by --O--, --CO--, --COO--, --OCO-- or --HC═
- CH--,Z1 and Z2 in each case are, independently from each other, a single bond, --CH2 CH2 --, --COO--, --OCO--, --C.tbd.C--, --CH2 O-- or --OCH2 --,A1 and A2 in each case are, independently from each other, trans-1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, 3-fluoro-1,4-phenylene, 2,3-difluoro-1,4-phenylene, or 3,5-difluoro-1,4-phenylene,X is --Q--P,P is --F, --Cl or --NCS,Q is --(O)m --Cs Fp H2s--p or a single bond,Y is --H, --F or --Cl,m is 0 or 1,s is 1, 2, 3 or 4,p is an integer from 0 up to 2s, andn is 0, 1 or 2; and
said alignment layers are each based on at least partially fluorinated polyimides.
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Abstract
The invention relates to a liquid crystal display element which contains an electrically switchable, dielectrically positive twisted nematic liquid crystal layer between two substrates which together with a frame form a cell, and two layers with alignment layers thereon applied to the substrates. The liquid crystal mixture is based on SFM compounds. One of the electrodes forming an active matrix of non-linear switching elements is integrated within each picture element while the other electrode is the counter electrode. The alignment layer is an organic polymer layer which may be essential uniformly aligned by rubbing. The alignment layer results in an essential homogenous surface alignment of the liquid crystal layer with a surface tilt angle. The liquid crystal material comprises at least 30 wt. % of one or more compounds according to formula I ##STR1## wherein R, Z1, Z2, A1, A2, X, Y and n are herein defined, and the alignment layer is based on at least partially fluorinated polyimides.
39 Citations
26 Claims
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1. A liquid crystal display comprising
an electrically switchable, dielectrically positive twisted nematic liquid crystal mixture layer between two substrates which together with a frame form a cell, said liquid crystal mixture is essentially based on superfluorinated liquid crystal compounds, two electrode layers, with alignment layers thereon, applied to said substrates, one of said electrode layers forms an active matrix of non-linear switching elements integrated with each picture element, and the other electrode layer is the counter electrode, said alignment layers are each an organic polymer layer which are essentially uniformly alignable by rubbing, said alignment layers resulting in an essential homogeneous surface alignment of the liquid crystal layer with a surface tilt angle, wherein said liquid crystal mixture comprises at least 30 wt. % of one or more compounds according to formula I ##STR23## wherein R is alkyl with up to 12 C atoms or alkyl with up to 12 C atoms wherein one or two non-adjacent CH2 -groups are each replaced by --O--, --CO--, --COO--, --OCO-- or --HC═ - CH--,
Z1 and Z2 in each case are, independently from each other, a single bond, --CH2 CH2 --, --COO--, --OCO--, --C.tbd.C--, --CH2 O-- or --OCH2 --, A1 and A2 in each case are, independently from each other, trans-1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, 3-fluoro-1,4-phenylene, 2,3-difluoro-1,4-phenylene, or 3,5-difluoro-1,4-phenylene, X is --Q--P, P is --F, --Cl or --NCS, Q is --(O)m --Cs Fp H2s--p or a single bond, Y is --H, --F or --Cl, m is 0 or 1, s is 1, 2, 3 or 4, p is an integer from 0 up to 2s, and n is 0, 1 or 2; and said alignment layers are each based on at least partially fluorinated polyimides. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26)
- CH--,
Specification