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Multi-Domain, Tilted-Nematic Liquid Crystal Display

IP.com Disclosure Number: IPCOM000123284D
Original Publication Date: 1998-Aug-01
Included in the Prior Art Database: 2005-Apr-04

Publishing Venue

IBM

Related People

Nakayama, K: AUTHOR [+2]

Abstract

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Multi-Domain, Tilted-Nematic Liquid Crystal Display

   Disclosed is a method to spreading viewing angle for the
liquid-crystal- display without changing any materials as used for
ordinary twisted-nematic TFT-LCD (liquid-crystal-display).

   Ordinary TFT-LCD is established by the namatic liquid
crystal material that is twisted 90 degrees in the glass cell as
shown in Fig 1.  When some voltage applied between the inner sides of
glass, liquid crystal is to be directed along the perpendicular to
the glass surface.  The angle between liquid crystal axis and the
glass surface is called tilt angle.  Higher the applied voltage is,
higher the tilt angle is.  With high voltage enough, tilt angle at
the center of liquid crystal layer is almost 90 degrees.  And the
symmetricity of the liquid crystal alignment in the plane parallel to
the glass surface is established roughly.  However, with the voltage
not so high, tilt angle is not so high.  Either, symmetricity of
liquid crystal alignment is no longer established.  This asymmetry
leads to the asymmetry of the viewing-angle of the liquid crystal
display as shown in Figs 2 and 3.  The second reason of the asymmetry
of the liquid-crystal-display comes from the liquid crystal direction
at the surface of the glass.  Liquid crystal direction of each side
of the glass surface are not symmetrical each other at the laboratory
system.

   To reduce the problem by the second reason above, asymmetry
of the liquid crystal direction n...