Ferroelectric liquid crystal display

• US 7,212,269 B2
• Filed: 07/02/2004
• Issued: 05/01/2007
• Est. Priority Date: 12/30/2000
• Status: Expired due to Term

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Philips LCD Company Limited (LG Display Co., Ltd.)
• Inventors: Choi, Su Seok, Choi, Suk Won
• Primary Examiner(s): Nelms; David
• Assistant Examiner(s): Caley; Michael H.
• Application Number:
  US10/882,688
• Publication Number:
  US 20050024568A1
• Time in Patent Office: 1,033 Days
• Field of Search: 349/128, 349/133, 349/134, 349/171, 349/172
• US Class Current: 349/133
• CPC Class Codes: G02F 1/1337 Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers
• CPC Class Codes: G02F 1/141 using ferroelectric liquid crystals

Abstract

A ferroelectric liquid crystal display having alignment films with different surface polarities. The alignment films induce an internal electric field through the liquid crystal. Because of the induced internal electric field, initial liquid crystal alignment, and subsequent liquid crystal alignments, can be performed without an externally applied electric field.

Claims

1. A method of fabricating a liquid crystal display device, comprising:

forming a first alignment film having a first surface polarity on a first substrate;

forming a second alignment film having a second surface polarity on a second substrate, wherein the second surface polarity is different from the first surface polarity;

spacing the first and second substrates apart by a gap;

providing a ferroelectric liquid crystal between the first and second substrates; and

aligning the ferroelectric liquid crystal by an internal electric field across the ferroelectric liquid crystal, wherein the different surface polarities induce the internal electric field and the ferroelectric liquid crystal phase-changes into a smectic phase during the alignment of the ferroelectric liquid crystal.

2. The method according to claim 1, wherein said first alignment film and said second alignment film are alignment treated in parallel directions.

3. The method according to claim 1, wherein said ferroelectric liquid crystal is aligned in parallel to said alignment treatment direction of said first alignment film and said second alignment film.

4. The method according to claim 1, wherein said first alignment film and said second alignment film have different material structures.

5. The method according to claim 4, wherein said first alignment film and said second alignment film have different side chain molecular structures.

6. The method according to claim 5, wherein said first alignment film and said second alignment film are polyimides.

7. The method according to claim 1, wherein said first alignment film and said second alignment film have undergone different temperature treatments.

8. The method according to claim 1, wherein said first alignment film and said second alignment film have undergone different alignment treatments.

9. The method according to claim 1, wherein said ferroelectric liquid crystal display is driven by an external applied potential, and wherein said external applied potential compensates for said internal electric field.