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AssigneeDisplaytech, Inc.
InventorsDavid M. Walba, Daniel J. Dyer, Uwe Muller, Peter Cobben, Xin Hua Chen, William Thurmes, Michael Wand
Estimating the term…
This invention provides LC compositions useful as birefringent materials in electrooptic devices which exhibit zero or low negatively sloped birefringence dispersion (e.g., exhibiting positive birefringence dispersion significantly lower than that of currently available LC compositions) or more preferably positively sloped birefringence dispersion in which birefringence of the material increases with wavelength. The invention provides compounds useful as components of LC compositions which exhibit negative birefringence where n.sub.o is higher than n.sub.e. The compounds of this invention are dimers of LC-like compounds in which the monomers are linked to each other through a high birefringence moiety (dimerization linker). The LC monomers consist of an LC core and one or two tail groups. Preferred monomers for this invention have low birefringence in comparison to the birefrigence of the monomer linking moiety. The dimers have normal positive birefringence dispersion to have birefringence that is lower in absolute value at longer wavelengths. But since they have negative birefringence, their birefringence actually increases (i.e., goes less negative) as wavelength increases.
A compound of formula I:
The compound of claim 227 wherein one of X or Z is --NO.sub.2 and the other of X or Z is --NR"R'" where R" and R'" are independently selected from the group H or an alkyl group having from 1 to about 6 carbon atoms.
A liquid crystal composition comprising a rod-like liquid crystal molecule exhibiting negative birefringence and
A liquid crystal composition comprising a rod-like liquid crystal molecule that is a dimer exhibiting negative birefringence and which comprises liquid crystal monomers each of which has a liquid crystal core comprising one or more aromatic rings.
Dependencies are inferred from the claim text.