Liquid crystal display and method for manufacturing same

• US 8,758,871 B2
• Filed: 08/17/2011
• Issued: 06/24/2014
• Est. Priority Date: 12/09/2002
• Status: Expired due to Fees

• Current Assignee: Japan Display Incorporated
• Original Assignee: Japan Display Incorporated, Panasonic Liquid Crystal Display Company Limited (Panasonic Holdings Corporation)
• Inventors: Tomioka, Yasushi, Abe, Hidetoshi, Kondo, Katsumi
• Primary Examiner(s): WU, SHEAN CHIU
• Application Number:
  US13/212,072
• Publication Number:
  US 20110301324A1
• Time in Patent Office: 1,042 Days
• Field of Search: 428/1.2, 428/1.25, 428/1.26, 428/1.27, 252/299.4, 349/123, 349/135, 525/425, 528/343.344
• US Class Current: 428/1.2
• CPC Class Codes: C09D 179/08 Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
• CPC Class Codes: C09K 19/542 Macromolecular compounds
• CPC Class Codes: C09K 19/56 Aligning agents
• CPC Class Codes: C09K 2019/548 stabilizing the alignment; Polymer stabilized alignment
• CPC Class Codes: C09K 2323/00 Functional layers of liquid crystal optical display excluding electroactive liquid crystal layer characterised by chemical composition
• CPC Class Codes: C09K 2323/02 Alignment layer characterised by chemical composition
• CPC Class Codes: C09K 2323/025 Polyamide
• CPC Class Codes: C09K 2323/027 Polyimide
• CPC Class Codes: C09K 2323/0271 Polyimidfluoride
• CPC Class Codes: C09K 2323/03 Viewing layer characterised by chemical composition
• CPC Class Codes: G02F 1/133723 Polyimide, polyamide-imide
• CPC Class Codes: G02F 1/133788 by light irradiation, e.g. linearly polarised light photo-polymerisation
• CPC Class Codes: G02F 1/134363 for applying an electric field parallel to the substrate, i.e. in-plane switching [IPS]
• CPC Class Codes: G02F 2201/121 common or background
• CPC Class Codes: G02F 2201/123 pixel
• CPC Class Codes: G02F 2202/08 glass transition temperature

Abstract

A liquid crystal display is provided which is capable of reducing the occurrence of defective display due to variations in the initial alignment direction of a liquid crystal alignment control film in a liquid crystal display of an IPS scheme, realizing the stable liquid crystal alignment, providing excellent mass productivity, and having high image quality with a higher contrast ratio. The liquid crystal display has a liquid crystal layer disposed between a pair of substrates, at least one of the substrates being transparent, and an alignment control film formed between the liquid crystal layer and the substrate. At least one of the alignment control films 109 comprises photoreactive polyimide and/or polyamic acid provided with an alignment control ability by irradiation of substantially linearly polarized light.

Claims

1. An alignment control film, adapted to be an alignment control film of a liquid crystal display to drive a liquid crystal with an electric field arising between a pair of electrodes formed on a substrate, comprising a polyamic acid or polyimide that includes cyclobutanetetracarboxylic acid dianhydride and/or its derivative and aromatic diamine;

and

wherein the cyclobutanetetracarboxylic acid dianhydride and/or its derivative is a compound represented by a formula [1];

2. The alignment control film according to claim 1, wherein said alignment control film is polyamic acid or polyimide containing at least 50% of a repeated structure of polyamic acid or polyimide comprising said cyclobutanetetracarboxylic acid dianhydride and/or its derivative and said aromatic diamine.

3. The alignment control film according to claim 1, having a glass transition temperature equal to or higher than 250°

C.

4. The alignment control film according to claim 1, wherein said polyamic acid or polyimide is a photoreactive polyamic acid or polyimide.

5. The alignment control film according to claim 1, wherein said thickness is 1 to 30 nm.

6. The alignment control film according to claim 1, said film having been subjected to alignment processing by irradiating the film with polarized light having a wavelength in a range of 200 to 400 nm.

7. The alignment control film according to claim 1, adapted to be an alignment control film of a liquid crystal display having an electric field parallel to said substrate.

8. A method for using an alignment control film, adapted to be an alignment control film of a liquid crystal display to drive a liquid crystal with an electric field arising between a pair of electrodes formed on one substrate of a pair of substrates, the alignment control film comprising a polyamic acid or polyimide that includes cyclobutanetetracarboxylic acid dianhydride and/or its derivative and aromatic diamine, the method for using an alignment control film comprising:

providing the alignment control film on at least one of the pair of substrates;

wherein the cyclobutanetetracarboxylic acid dianhydride and/or its derivative is a compound represented by a formula [1];

9. The method for using an alignment control film according to claim 8, wherein said alignment control film is polyamic acid or polyimide containing at least 50% of a repeated structure of polyamic acid or polyimide comprising said cyclobutanetetracarboxylic acid dianhydride and/or its derivative and said aromatic diamine.

10. The method for using an alignment control film according to claim 8, having a glass transition temperature equal to or higher than 250°

C.

11. The method for using an alignment control film according to claim 8, wherein said polyamic acid or polyimide is a photoreactive polyamic acid or polyimide.

12. The method for using an alignment control film according to claim 8, wherein said thickness is 1 to 30 nm.

13. The method for using an alignment control film according to claim 8, said film having been subjected to alignment processing by irradiating the film with polarized light having a wavelength in a range of 200 to 400 nm.

14. The method for using an alignment control film according to claim 8, adapted to be an alignment control film of a liquid crystal display having an electric field parallel to said substrate.