Browse Prior Art Database

New Hybrid Alignment Method for Active Matrix Liquid Crystal Displays

IP.com Disclosure Number: IPCOM000106825D
Original Publication Date: 1993-Dec-01
Included in the Prior Art Database: 2005-Mar-21
Document File: 2 page(s) / 70K

Publishing Venue

IBM

Related People

Lien, SC: AUTHOR

Abstract

Disclosed is a new hybrid alignment method for active matrix liquid crystal displays to prevent static and mechanical damage to the active matrix elements and to assure a good alignment quality.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

New Hybrid Alignment Method for Active Matrix Liquid Crystal Displays

      Disclosed is a new hybrid alignment method for active matrix
liquid crystal displays to prevent static and mechanical damage to
the active matrix elements and to assure a good alignment quality.

      The Active Matrix Liquid Crystal Cisplay (AMLCD) [*] has drawn
much attention because it can display more information with better
performance than conventional multiplexing LCDs.   The liquid crystal
alignment in an AMLCD is commonly achieved by using the rubbed
polyimide film.  This alignment method gives the LCD a good alignment
quality and long-time stability.  However, its mechanical rubbing may
cause mechanical and/or static damage to the active matrix elements.
On the other hand, an active matrix LCD aligned by Langmuir-Blodgett

(LB) film or by the oblique deposition of the oxide film would not
have mechanical and static problems.  The disadvantage of the LB film
alignment is that it usually gives LCD a low or zero pretilt angle,
which causes a disclination line defect to occurr near the middle of
the pixel.  Thus, the display optical quality would be greatly
deteriorated.  The disadvantage of the alignment with the oblique
deposition of the oxide film is that it causes the LCD to have a too
high pretilt angle, which greatly reduces the contrast ratio of the
display.  Therefore, there is not a good method to align an active
matrix so far.  In this disclosure, a new hybrid alignment method is
disclosed.  Use of this new method to align an active matrix LCD will
prevent static and mechanical damage to the active matrix elements
and will assure a good alignment quality.

      The new method to align an active matrix LCD is that the active
matrix substrate is aligned by LB film alignment and the counter
substrate (the non-active matrix substrate) is aligned by rubbed...