Method of alignment of liquid crystals comprising exposing an alignment material to an interference pattern

• US 7,196,758 B2
• Filed: 12/30/2003
• Issued: 03/27/2007
• Est. Priority Date: 12/30/2003
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company), Brown University
• Original Assignee: 3M Innovative Properties Company (3M Company), Brown University
• Inventors: Radcliffe, Marc D., Eakin, James N., Crawford, Gregory P.
• Primary Examiner(s): Schechter; Andrew
• Assistant Examiner(s): CHEN, WEN YING PATTY
• Application Number:
  US10/748,562
• Publication Number:
  US 20050140837A1
• Time in Patent Office: 1,183 Days
• Field of Search: 349/127
• US Class Current: 349/129
• CPC Class Codes: G02F 1/133788 by light irradiation, e.g. linearly polarised light photo-polymerisation

Abstract

A method includes exposing an alignment material to an interference pattern to cause a chemical reaction in the alignment material and exposing the alignment material to a liquid crystal, where the liquid crystal aligns relative to the alignment material based on the interference pattern.

Claims

1. A method, comprising:

exposing an alignment material to an interference pattern having uniform intensity formed from two beams having circular polarization states of opposite handedness to cause a chemical reaction in the alignment material; and

exposing the alignment material to a liquid crystal,

wherein the liquid crystal aligns relative to the alignment material based on the interference pattern.

2. The method of claim 1, wherein the chemical reaction causes polymerization in the alignment material.

3. The method of claim 1, wherein the chemical reaction causes depolymerization in the alignment material.

4. The method of claim 1, wherein the chemical reaction comprises a photochemical reaction.

5. The method of claim 1, wherein a surface of the alignment material is exposed to the interference pattern.

6. The method of claim 5, wherein the surface is substantially planar.

7. The method of claim 5, wherein the surface is curved.

8. The method of claim 7, wherein the surface is an inner-surface of a tube.

9. The method of claim 8, wherein the tube comprises one of a glass and a polymer.

10. The method of claim 5, wherein the surface comprises a channel.

11. The method of claim 1, wherein the alignment material is disposed on a surface of a substrate comprising a substrate material.

12. The method of claim 11, wherein the substrate material is at least one of a glass, a polymer, a metal and a semi-conductor.

13. The method of claim 12, wherein the substrate comprises an electrode layer.

14. The method of claim 13, wherein the electrode layer comprises a transparent electrically conductive material.

15. The method of claim 12, wherein the substrate comprises a thin film transistor.

16. The method of claim 1, wherein the liquid crystal permeates the alignment material.

17. The method of claim 1, wherein the alignment material comprises a liquid crystal.

18. The method of claim 1, wherein the alignment material comprises a polymer.

19. The method of claim 18, wherein the polymer comprises a cinnamate group.

20. The method of claim 18, wherein the polymer is a polyimide.

21. The method of claim 1, wherein the alignment material comprises a silane.

22. The method of claim 1, wherein the beams comprise UV radiation.

23. The method of claim 1, wherein the interference pattern comprises regions of different polarization.

24. The method of claim 23, wherein the interference pattern comprises regions of different linear polarization.

25. The method of claim 23, wherein the liquid crystal aligns relative to the alignment material based on the polarization of the interference pattern.

26. The method of claim 1, wherein at least a portion of the liquid crystal aligns substantially homogeneously relative to a surface of the alignment material.

27. The method of claim 1, wherein the liquid crystal is disposed on the surface prior to exposure to the interference pattern.

28. The method of claim 1, wherein the liquid crystal is disposed on the surface after exposure to the interference pattern.

29. The method of claim 1, further comprising rubbing a surface of the alignment material prior to exposing the alignment material to the interference pattern.

30. The method of claim 1, further comprising exposing a surface of the alignment material to polarized radiation prior to exposing the alignment material to the interference pattern.