Browse Prior Art Database

Cell Structure of Thin Film Transistor-Liquid Crystal Display with Compensator to Spread Viewing-Cone

IP.com Disclosure Number: IPCOM000118114D
Original Publication Date: 1996-Sep-01
Included in the Prior Art Database: 2005-Apr-01
Document File: 4 page(s) / 81K

Publishing Venue

IBM

Related People

Nakayama, K: AUTHOR [+2]

Abstract

The disclosed invention shows: 1. A cell structure with a compensation film to spread the viewing-cone, and 2. A compensation film which is a negative uniaxis anisotropy.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 91% of the total text.

Cell Structure of Thin Film Transistor-Liquid Crystal Display with
Compensator to Spread Viewing-Cone

      The disclosed invention shows:
  1.  A cell structure with a compensation film to spread the
       viewing-cone, and
  2.  A compensation film which is a negative uniaxis anisotropy.

When it is applied on a TN-Liquid Crystal Display (LCD) in an
adequate direction, it shows some advantage other than ordinary
TN-LCD, such as a darker black state, wide no-grey-inversion angle.

      Today, some compensation films are used for Standard (STN)-LCD,
but not for TN-TFT-LCD.  Also, an absorption axis of
polarizer/analyzer is parallel or perpendicular to the LC alignment
direction (rubbing direction) for O-mode and E-mode respectively, as
shown in Fig. 1.

      When compensation films on each side of an LCD cell are used,
and a polarizer and an analyzer are used without using neither
parallel direction nor perpendicular direction to LC alignment
direction, as shown in Fig. 2, a darker black-state is obtained, as
shown in Fig. 3.  Also, a wider viewing angle in no-grey-inversion,
as shown in Fig. 4, is obtained.

      Especially, when the conditions below are held, much advantage
in the viewing-cone would be received:
  1.  Absorption axis of polarizer/analyzer is 45º  from LC
       alignment direction, as shown in Fig. 2.
  2.  Compensation film is made of a discotic liquid crystal having
       the nature of negative uniaxis a...