Browse Prior Art Database

Controlled Reverse Tilt Guest-Host Liquid Crystal Display

IP.com Disclosure Number: IPCOM000119611D
Original Publication Date: 1991-Feb-01
Included in the Prior Art Database: 2005-Apr-02
Document File: 3 page(s) / 84K

Publishing Venue

IBM

Related People

Takano, H: AUTHOR

Abstract

Disclosed is a liquid crystal display (LCD) which is suited for gray scale application and its fabrication method. The features of the disclosed LCD are as follows: (1) the best viewing direction is panel normal, (2) optical characteristics are nearly symmetrical in UP, DOWN, RIGHT and LEFT azimuthal viewing zones, and (3) polar viewing angle dependence of the optical characteristics is considerably small.

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Controlled Reverse Tilt Guest-Host Liquid Crystal Display

      Disclosed is a liquid crystal display (LCD) which is
suited for gray scale application and its fabrication method.  The
features of the disclosed LCD are as follows:
      (1)  the best viewing direction is panel normal,
      (2)  optical characteristics are nearly symmetrical in
           UP, DOWN, RIGHT and LEFT azimuthal viewing zones,
           and
      (3)  polar viewing angle dependence of the optical
           characteristics is considerably small.

      The features described above are really required in a
large-size gray scale display.  Even though a guest-host (GH) LCD has
better viewing angle dependence than a twisted nematic (TN) LCD, its
good viewing direction is not parallel to the panel normal, and it
shows considerable difference in optical characteristics between good
viewing zone (UP zone) and bad viewing zone (DOWN zone).

      Disclosed GH LCD achieves the above feature by dividing each
picture element into two nearly same-size domains in which the
optimum viewing directions are opposite each other.

      Fig. 1 shows polar viewing angle dependence of electro-optical
characteristics of conventional and disclosed GH LCD. The former has
large polar angular dependence in UP and DOWN viewing zone.  On the
contrary, the latter has almost the same linear characteristics in
the UP, DOWN, RIGHT and LEFT viewing zones.

    ...