IP Library › Granted Patent US 7,139,063
Granted Patent B2
US 7,139,063 · App. 09/749,440 · Granted Nov 21, 2006

Fabricating method for liquid crystal panel implementing ferroelectric liquid crystal and operating in a monostable state

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Quick Facts
Patent No.
US 7,139,063
App. No.
09/749,440
Granted
Nov 21, 2006
Kind
B2
Abstract

In the preferred embodiment of the present invention, a ferroelectric LC layer is formed between first and second substrates of a LC panel. The LC panel is cooled at a low temperature, for example at −20° C., where the ferroelectric LC maintains a smetic phase. Due to the cooling, molecules are uniformly aligned for their early alignment state.

Claims (51)

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

forming a liquid crystal panel including first and second substrates;

forming a ferroelectric liquid crystal layer between the first and second substrates of the liquid crystal panel;

cooling the liquid crystal panel to a predetermined temperature so as to produce monostable alignment within the ferroelectric liquid crystal;

heating the cooled liquid crystal panel substantially to room temperature; and

operating the liquid crystal display device in a monostable state.

2. The method of claim 1 , wherein the predetermined temperature is in a range around −-20° C.

3. The method of claim 1 , wherein the ferroelectric liquid crystal layer includes an anti-ferroelectric liquid crystal layer.

4. The method of claim 1 , wherein the cooling produces a chiral smectic C phase in the ferroelectric liquid crystal.

5. The method of claim 1 , wherein the cooling produces a chiral smectic C A phase in the ferroelectric liquid crystal.

6. The method of claim 1 , wherein the first substrate includes a transparent material.

7. The method of claim 1 , further comprising a step of forming a pixel electrode on the first substrate.

8. The method of claim 1 , further comprising a step of forming a thin film transistor on the first substrate.

9. The method of claim 1 , further comprising a step of forming a color filter on the second substrate.

10. The method of claim 1 , wherein the predetermined temperature is below a smectic phase temperature.

11. The method of claim 1 , wherein the ferro electric liquid crystal layer includes 2-methylbutyl p-[p(decyloxybenzylidene)-amino]-cinnamate (DOBAMBC).

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

forming a liquid crystal panel having a first substrate and a second substrate;

interposing a ferroelectric liquid crystal layer comprised of liquid crystal molecules, between the first substrate and the second substrate;

cooling the liquid crystal layer to a predetermined temperature to form a monostable alignment of the liquid crystal molecules;

heating the cooled liquid crystal layer substantially to room temperature; and

operating the liquid crystal display device in a monostable state.

13. A method of fabricating a liquid crystal display device according to claim 12 , wherein the predetermined temperature is below a smectic phase temperature.

14. A method of fabricating a liquid crystal display device according to claim 13 , wherein the liquid crystal layer is subsequently heated above the smectic phase temperature.

15. A method of fabricating a liquid crystal display device according to claim 12 , wherein the predetermined temperature is about −20° C.

16. A method of fabricating a liquid crystal display device according to claim 12 , wherein the ferro electric liquid crystal layer includes an anti-ferroelectric liquid crystal layer.

17. A method of fabricating a liquid crystal display device according to claim 12 , wherein the cooling produces a chiral smectic C phase in the ferroelectric liquid crystal layer.

18. A method of fabricating a liquid crystal display device according to claim 12 , wherein the cooling produces a chiral smectic C A phase in the ferro electric liquid crystal layer.

19. A method of fabricating a liquid crystal display device according to claim 12 , wherein the ferroelectric liquid crystal layer includes 2-methylbutyl p-[[p(decyloxybenzylidene)-amino]-cinnamate (DOBAMBC).

20. A method of improving the contrast ratio of a liquid crystal display device, comprising:

forming a liquid crystal panel having a first substrate, a second substrate, and an interposed ferroelectric liquid crystal layer that is comprised of liquid crystal molecules;

cooling the liquid crystal layer to a predetermined temperature to form a monostable alignment of the liquid crystal molecules;

heating the cooled liquid crystal layer substantially to room temperature;

operating the liquid crystal display device in a monostable state; and

passing light through said liquid crystal panel.

21. A method of improving the contrast ratio of a liquid crystal display device according to claim 20 , wherein the predetermined temperature is below a smectic phase temperature.

22. A method of improving the contrast ratio of a liquid crystal display device according to claim 21 , wherein the liquid crystal layer is subsequently heated above the smectic phase temperature.

23. A method of improving the contrast ratio of a liquid crystal display device according to claim 20 , wherein the ferroelectric liquid crystal layer includes 2-methylbutyl p-[p(decyloxybenzylidene)-amino]-cinnamate (DOBAMBC).

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

forming a liquid crystal panel including first and second substrates;

forming a ferroelectric liquid crystal layer between the first and second substrates of the liquid crystal panel;

cooling the liquid crystal panel to a predetermined temperature so as to produce monostable alignment within the ferroelectric liquid crystal; and

heating the cooled liquid crystal panel substantially to room temperature;

wherein the predetermined temperature is in a range around −20° C.

25. The method of claim 24 , wherein the ferroelectric liquid crystal layer includes an anti-ferroelectric liquid crystal layer.

26. The method of claim 24 , wherein the cooling produces a chiral smectic C phase in the ferroelectric liquid crystal.

27. The method of claim 24 , wherein the cooling produces a chiral smectic C A phase in the ferroelectric liquid crystal.

28. The method of claim 24 , wherein the first substrate includes a transparent material.

29. The method of claim 24 , further comprising a step of forming a pixel electrode on the first substrate.

30. The method of claim 24 , further comprising a step of forming a thin film transistor on the first substrate.

31. The method of claim 24 , further comprising a step of forming a color filter on the second substrate.

Assignments (1)
CHANGE OF NAME Recorded Oct 17, 2008
From: LG.PHILIPS LCD CO., LTD.
To: LG DISPLAY CO., LTD.
Reel/Frame 021763/0177 →