Browse Prior Art Database

High Transmittance Thin Film Transistor/Liquid Crystal Display

IP.com Disclosure Number: IPCOM000114987D
Original Publication Date: 1995-Feb-01
Included in the Prior Art Database: 2005-Mar-30
Document File: 2 page(s) / 45K

Publishing Venue

IBM

Related People

Kodate, M: AUTHOR [+2]

Abstract

Disclosed are the combination of two optical eigen-modes and two different grade of polarizers of the Twisted Nematic Liquid Crystal Display (TN LCD); by this combination higher transmittance with minimum degradation of the contrast ratio is realized.

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High Transmittance Thin Film Transistor/Liquid Crystal Display

      Disclosed are the combination of two optical eigen-modes and
two different grade of polarizers of the Twisted Nematic Liquid
Crystal Display (TN LCD); by this combination higher transmittance
with minimum degradation of the contrast ratio is realized.

       For the Thin-Film-Transistor (TFT) addressed LCD, the
contrast ratio was considered to be more important factor than the
transmittance.  Therefore, "high contrast" grade of polarizers are
adopted for the TFT/LCD.  Recently, the requirement of high
transmission TFT/LCD becomes increased from the point of view of
energy saving and so on.  One of the solutions for the high
transmission TFT/LCD is to replace the "high contrast" polarizer by
the "high transmission" polarizer.  However, such TFT/LCD shows
remarkable degradation of contrast ratio.  Disclosed TFT/LCD provides
higher transmittance and minimum degradation of contrast ratio.

      Usually, same grade polarizers is used as the entrance and the
exit polarizers of TFT/LCD.  TFT/LCD shows rather low transmittance
when two "high contrast" polarizers are used.  On the other hand, it
shows large degradation of the contrast ratio when two "high
transmission" polarizers are used.  Disclosed TFT/LCD uses different
grade of polarizers, one is "high contrast" type and the other is
"high transmission" type, for the entrance and the exit surface.
There are two optical eigen-mode in norma...