Liquid crystal display device
AssigneeSeiko Epson Corporation
InventorChiyoaki Iijima
Life of this patent
Estimating the term…
Loading patent…
AssigneeSeiko Epson Corporation
InventorChiyoaki Iijima
Estimating the term…
A liquid crystal display device including a super twisted nematic liquid crystal material with a twist angle between about 180.degree. and 360.degree.. The liquid crystal composition includes at least one of a compound [I] and a compound [II] for lowering the threshold voltage and at least one of a compound [III] and a compound [IV] for widening the d/p range and improving .DELTA.(d/p). Compounds [I]-[IV] are represented by the general formulae: ##STR1## wherein R.sub.1 is R--, RO-- or RCH.dbd.CH--, R.sub.2 is R--, RO--, CN-- or F--, ##STR2## X is a single covalent bond, --C.tbd.C--, --CH.sub.2 CH.sub.2 -- or --COO--, ##STR3## if X is not --CH.sub.2 CH.sub.2 --; R.sub.3 is R--, RO-- or RCH.dbd.CH--, R.sub.4, R.sub.5 and R.sub.7 are R-- or RO--, Y is a single covalent bond or --CH.sub.2 CH.sub.2 --, ##STR4## if Y is a single covalent bond, ##STR5## R.sub.6 is --CN or --F, ##STR6## and R.sub.8 is --F, or --CN if ##STR7## and R is an alkyl group having from 1 to 9 carbon atoms. The composition includes at least 20 weight percent of compounds [I] and compounds [II] and between about 5 and 55 weight percent of compounds [III] and compounds [IV].
A liquid crystal display device, comprising:
Dependencies are inferred from the claim text.