Method and apparatus of forming alignment layer for liquid crystal display device

• US 7,728,933 B2
• Filed: 11/30/2005
• Issued: 06/01/2010
• Est. Priority Date: 02/07/2005
• Status: Expired due to Fees

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Shin, Kwang Hoon, Kim, Chang Dong, Seo, Hyun Sik
• Primary Examiner(s): Dudek; James A
• Application Number:
  US11/289,447
• Publication Number:
  US 20060176432A1
• Time in Patent Office: 1,644 Days
• Field of Search: 349/124
• US Class Current: 349/124
• CPC Class Codes: G02F 1/133723 Polyimide, polyamide-imide
• CPC Class Codes: G02F 1/133765 without a surface treatment
• CPC Class Codes: G02F 1/13378 by treatment of the surface, e.g. embossing, rubbing or light irradiation G02F1/133711, G02F1/133734, G02F1/133753 take precedence

Abstract

A method for forming an alignment layer is disclosed, to prevent light leakage generated by a physical contact between a rubbing roll and a substrate, which includes preparing a substrate; coating an alignment material on the substrate, for initial alignment of liquid crystal; applying an electric field or a magnetic field to the alignment material, for determination of alignment direction in the alignment material; and curing the alignment material.

Claims

1. A method for forming an alignment layer of an LCD device comprising:

preparing a substrate;

coating an alignment material on the substrate, for initial alignment of liquid crystal;

applying a field flux to the alignment material, for determination of alignment direction of the alignment material;

curing the alignment material by using a heater at a temperature below 100°

C.,

wherein applying the field flux is performed with the field flux application direction parallel to the X-axis, perpendicular to the X-axis, or diagonal to the X-axis depending on the alignment direction of the alignment material, and

changing a direction of the field flux by rotating a field flux generator while maintaining the substrate stationary or by rotating the substrate while maintaining the field flux generator stationary.

2. The method of claim 1, wherein the field flux is an electric field.

3. The method of claim 2, wherein the electric field is applied in the same direction as the alignment direction of the alignment material when performing the step of applying the electric field.

4. The method of claim 1, wherein the field flux is a magnetic field.

5. The method of claim 4, wherein the magnetic field is applied substantially perpendicular to the alignment direction of the alignment material.

6. The method of claim 4, wherein applying the magnetic field is performed with a pair of coiled electromagnets.

7. The method of claim 4, wherein applying the magnetic field is performed with a horseshoe magnet.

8. he method of claim 1, wherein coating the alignment material, applying the field flux, and curing the alignment material are performed in sequence.

9. The method of claim 1, wherein the step of preparing the substrate includes:

defining a pixel region on a transparent substrate by forming gate and data lines crossing each other;

forming a thin film transistor at an intersection of the gate and data lines, the thin film transistor including a gate electrode, a source electrode and a drain electrode; and

forming a pixel electrode connected with the drain electrode of the thin film transistor.

10. The method of claim 1, wherein the step of preparing the substrate includes:

defining a pixel region on a transparent substrate by forming gate and data lines crossing each other;

forming a thin film transistor at an intersection of the gate and data lines, the thin film transistor including a gate electrode, a source electrode and a drain electrode;

forming a pixel electrode connected with the drain electrode of the thin film transistor; and

forming a common electrode in parallel to the pixel electrode.

11. The method of claim 1, wherein the step of preparing the substrate includes:

forming a black matrix layer on a transparent substrate, for prevention of light leakage;

forming an R/G/B color filter layer on the black matrix layer; and

forming a common electrode on the color filter layer.

12. The method of claim 1, wherein the step of preparing the substrate includes:

forming a black matrix layer on a transparent substrate, for prevention of light leakage;

forming an R/G/B color filter layer on the black matrix layer; and

forming an overcoat layer on the color filter layer.

13. The method of claim 1, wherein the substrate is a plastic substrate.

14. The method of claim 1, wherein the substrate is a flexible substrate.

15. The method of claim 1, wherein the alignment material is formed of a polymer selected from polyimide, polyamic acid, polyvinylcinnamate, polyazobenzene, polyethyleneimine, polyvinylalcohol, polyamide, polyethylene, polystylene, polyphenylenephthalamide, polyester, polyurethane, or polymethylmethacrylate.

16. The method of claim 1, wherein changing a field flux application direction is performed by rotating a field flux generator while maintaining the substrate stationary.

17. The method of claim 2, wherein the electric field is applied by using an anode and a cathode coming into contact with both sides of the substrate.