TN cell having improved display of grey shades

Details TN cell having improved display of grey shades TN cell having improved display of grey shades

1996-12-11

1997-12-09

Sikes, William L.

Liquid crystal cells, elements and systems

With specified nonchemical characteristic of liquid crystal...

Within nematic phase

349180, G02F 113, C09K 1902

Patent

active

056965702

ABSTRACT:
The invention relates to a TN cell which contains a nematic liquid crystal having positive dielectric anisotropy and a twist angle of essentially 90.degree., between two substrates provided with electrode and alignment layers, where the product of the separation between the substrate plates d is between 0.15 and 0.70 .mu.m, characterized in that the liquid crystal contains a doping component in order to improve the grey shade capacity, so that the cell has a value for the undisturbed quotient of the separation between the substrate plates d and the pitch of the liquid crystal p of 0.1.ltoreq.d/p.ltoreq.0.5.

REFERENCES:
patent: 4143974 (1979-03-01), Aftergut et al.
patent: 4264148 (1981-04-01), Gobl-Wunsch et al.
patent: 4398803 (1983-08-01), Pohl et al.
patent: 4697884 (1987-10-01), Amstutz
patent: 4856875 (1989-08-01), Kozaki et al.
patent: 5102577 (1992-04-01), Uchida
patent: 5130834 (1992-07-01), Kano
patent: 5258135 (1993-11-01), Uchida
patent: 5286410 (1994-02-01), Weber
patent: 5323251 (1994-06-01), Coates
patent: 5376302 (1994-12-01), Coates
patent: 5476611 (1995-12-01), Nolan
H. Birecki et al., "Effects of Cell and Material Properties on Multiplexing Levels of Twisted Nematic Liquid Crystal Displays" in The Physics and Chemistry of Liquid Crystal Devices, edited by Gerald J. Sprokel, pp. 125-142 (1980). No Month.
H. Birecki et al., "The Optics of Twisted Nematic Liquid-Crystal Displays," J. Appl. Phys. vol. 51(4), (1980), pp. 1950-1954. No Month.
Data Base WPIL, Dewrwent Publications Ltd., Lond. G.B.; AN 83-03650K. No Date Avail.
Kumar, "Effect of Chiral Dopant Concentration on the Time Response of a Twisted Nematic Cell",Mol. Cryst. Liq. Cryst., vol. 144(1987), pp. 127-136. No month.
Gobl-Wunsch, et al. Le Journal de Physique, "Temperature Independent Threshold Voltage for an Electroptic Effect", vol. 40 8, pp. 773-777(1979) No month.
E.P. Raynes, Electronics Lett., "Improved Contrasts Uniformity in Twisted Nematic Liquid-Crystal Electro-Optic display Devices", vol. 10, pp. 141-142(1974) No month.
D.W. Berreman, J. Opt. Soc. Am., "Liquid-Crystal Twist Cell Dynamics with Backflow", vol. 46, pp. 3746-3751(1984) No month.
B. Bahadduer, Mol. Cryst. Liq. Cryst., "Liquid Crystal Displays", vol. 109, pp. 3-98(1984) No month.
D.W. Berreman, J. opt. Soc. Am., "Optics in Stratified and Anisotropic Media: 4.times.4 Matrix Formulation", vol. 62, pp. 502-510(1972) No month.
G. Baur, Mol. Cryst. Liq. Cryst., "The Influence of Material and device Parameters on the Optical Characteristics of Liquid Crystal Displays", vol. 63, pp. 45-58(1981) No month.
D.W. Berreman, Phil. Trans. R. Soc. Lond., "Numerical Modelling of Twisted Nematic Devices", vol. 309, pp. 133-146(1983) No month.
M. Schmidt, Mol. Cryst. Liq. Cryst., "Director Patters and Optical Performance of 2-D-Inhomogeneously Deformed Nematic Liquid Crystal Layers", vol. 206, pp. 65-77(1991) No month.
M. Schmidt, Dissertation Leipzig, 1990, pp. 55 & 58 No month.

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