Coating type optical film, fabrication method thereof and liquid crystal display using the optical film

• US 20050001955A1
• Filed: 12/29/2003
• Published: 01/06/2005
• Est. Priority Date: 07/02/2003
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Philips LCD Company Limited (LG Display Co., Ltd.)
• Inventors: Yoon, Sunghoe
• Granted Patent: US 7,271,864 B2
• Time in Patent Office: Days
• US Class Current: 349/96
• CPC Class Codes: G02F 1/133528 Polarisers
• CPC Class Codes: G02F 1/133531 characterised by the arrangement of polariser or analyser axes
• CPC Class Codes: G02F 1/133541 Circular polarisers
• CPC Class Codes: G02F 1/13356 characterised by the placement of the optical elements
• CPC Class Codes: G02F 1/13363 Birefringent elements, e.g. for optical compensation
• CPC Class Codes: G02F 1/133633 using mesogenic materials
• CPC Class Codes: G02F 2413/03 Number of plates being 3
• CPC Class Codes: G02F 2413/07 All plates on one side of the LC cell

Abstract

A coating type optical film has a linear polarizer formed on a high brightness optical film such as a circular polarizer formed using cholesteric liquid crystal and a phase difference film or an interference type linear polarizer using a coating method. In forming the linear polarizer by coating liquid crystal on the interference type linear polarizer, the liquid crystal is coated by using a bar coating method, a knife coating method or a slit-die coating method. The coated liquid crystal is lyotropic liquid crystal. The lyotropic liquid crystal can include dye and pigment. The linear polarizer formed in this way has an E-mode polarization.

Claims

1. A liquid crystal display comprising:

a liquid crystal panel having an upper plate, a lower plate and liquid crystal injected between the upper plate and the lower plate;

a polarizing plate disposed on the liquid crystal panel; and

an optical film containing a linear polarizer coated on a surface thereof, the linear polarizer having a light transmittance axis perpendicular to a light transmittance axis of the polarizing plate, the optical film positioned at a bottom surface of the liquid crystal panel.

2. A coating type optical film comprising:

a circular polarizer containing cholesteric liquid crystal;

an adhesive layer formed on the circular polarizer;

a phase difference film formed on the adhesive layer; and

a linear polarizer directly coated on the phase difference film.

3. The coating type optical film according to claim 2, further comprising a compensation film formed between the phase difference film and the circular polarizer.

4. The coating type optical film according to claim 2, wherein the linear polarizer comprises a lyotropic liquid crystal.

5. The coating type optical film according to claim 4, wherein the lyotropic liquid crystal contains dye or pigment.

6. The coating type optical film according to claim 2, wherein the optical film has a thickness of at most about 200 μ

m.

7. The coating type optical film according to claim 2, wherein the linear polarizer has a thickness of a few μ

m.

8. A coating type optical film comprising:

an interference type linear polarizer; and

a linear polarizer directly coated on the interference type linear polarizer.

9. The coating type optical film according to claim 8, wherein the linear polarizer comprises a lyotropic liquid crystal.

10. The coating type optical film according to claim 9, wherein the lyotropic liquid crystal contains dye or pigment.

11. The coating type optical film according to claim 8, wherein the optical film has a thickness of at most about 200 μ

m.

12. The coating type optical film according to claim 8, wherein the linear polarizer has a thickness of a few μ

m.

13. A method for fabricating a coating type optical film, comprising:

(a) forming a circular polarizer containing cholesteric liquid crystal on a transparent substrate;

(b) forming an adhesive layer on the circular polarizer;

(c) forming a phase difference film on the adhesive layer; and

(d) forming a linear polarizer by directly coating liquid crystal on the phase difference film.

14. The method according to claim 13, further comprising:

(e) after (b), forming a compensation film; and

(f) forming another adhesive layer on the compensation film.

15. The method according to claim 13, wherein the liquid crystal is coated by a method selected from the group consisting of a bar coating method, a knife coating method and a slit-die coating method.

16. The method according to claim 13, wherein the coated liquid crystal comprises a lyotropic liquid crystal.

17. The method according to claim 16, wherein the lyotropic liquid crystal contains dye or pigment.

18. The method according to claim 13, wherein the linear polarizer has an E-mode polarization.

19. The method according to claim 13, wherein the optical film has a thickness of at most about 200 μ

m.

20. The method according to claim 13, wherein the linear polarizer has a thickness of a few μ

m.

21. A method for fabricating a coating type optical film, comprising:

(a) preparing an interference type linear polarizer; and

(b) forming a linear polarizer by directly coating liquid crystal on the interference type linear polarizer.

22. The method according to claim 21, wherein the liquid crystal is coated by a method selected from the group consisting of a bar coating method, a knife coating method and a slit-die coating method.

23. The method according to claim 21, wherein the coated liquid crystal comprises a lyotropic liquid crystal.

24. The method according to claim 23, wherein the lyotropic liquid crystal includes dye or pigment.

25. The method according to claim 21, wherein the linear polarizer has an E-mode polarization.

26. The method according to claim 21, wherein the optical film has a thickness of at most about 200 μ

m.

27. The method according to claim 21, wherein the linear polarizer has a thickness of a few μ

m.

28. A coating type optical film comprising:

a circular polarizer containing cholesteric liquid crystal;

an adhesive layer formed on the circular polarizer;

a phase difference film formed on the adhesive layer; and

a linear polarizer directly coated on a substrate adhered to a top of the phase difference film.

29. The coating type optical film according to claim 28, wherein the linear polarizer comprises a lyotropic liquid crystal.

30. The coating type optical film according to claim 29, wherein the lyotropic liquid crystal contains dye or pigment.

31. The coating type optical film according to claim 28, wherein the optical film has a thickness of at most about 200 μ

m.

32. The coating type optical film according to claim 28, wherein the linear polarizer has a thickness of a few μ

m.

33. A coating type optical film comprising:

an interference type linear polarizer; and

a linear polarizer directly coated on a substrate adhered to a top of the interference type linear polarizer.

34. The coating type optical film according to claim 33, wherein the linear polarizer comprises a lyotropic liquid crystal.

35. The coating type optical film according to claim 34, wherein the lyotropic liquid crystal contains dye or pigment.

36. The coating type optical film according to claim 33, wherein the optical film has a thickness of at most about 200 μ

m.

37. The coating type optical film according to claim 33, wherein the linear polarizer has a thickness of a few μ

m.