Liquid crystal display having a conductive high molecular film for preventing the fringe field in the in-plane switching mode

• US 5,959,708 A
• Filed: 06/19/1997
• Issued: 09/28/1999
• Est. Priority Date: 06/21/1996
• Status: Expired due to Term

• Current Assignee: BOE HYDIS Technology Company Limited (SK Hynix Inc.)
• Original Assignee: Hyundai Electronics Industries Co. Ltd. (SK Hynix Inc.)
• Inventors: Lee, Seung-Hee, Kim, Hyang-Yul, Lee, Deuk-Su, Roh, Bong-Gyu, Park, Han-Jun
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): Eisenhut, Heidi L.
• Application Number:
  US08/878,809
• Time in Patent Office: 831 Days
• Field of Search: 349/141, 349/143, 349/122, 349/123
• US Class Current: 349/143
• CPC Class Codes: G02F 1/134363 for applying an electric field parallel to the substrate, i.e. in-plane switching [IPS]

Abstract

Disclosed is a liquid crystal display device having a pixel electrode and a counter electrode formed on one substrate device. The device includes: a first transparent substrate having a conductive high molecular film formed on the pixel electrode and the counter electrode; a second transparent substrate arranged parallel to the first transparent substrate; and a liquid crystal material disposed between the first and second transparent substrates, for selectively scattering or transmitting light in response to a prescribed input.

Claims

1. A liquid crystal display device wherein a counter electrode and a pixel electrode are formed on a transparent insulating substrate, comprising:

a first transparent insulating substrate having a conductive high molecular film formed on the pixel electrode and counter electrode, preventing the fringe field in the in-plane switching mode;

a second transparent insulating substrate arranged parallel to the first transparent insulating substrate; and

a liquid crystal material disposed between the first and second transparent insulating substrates, for selectively transmitting light in response to a prescribed input.

2. The liquid crystal display device as claimed in claim 1, wherein said high molecular film comprises a material selected from a group consisting of polyacetylene, polyaniline, p-phenylene, polypyrrole, polythiophene and p-phenylenevinylene.

3. The liquid crystal display device as claimed in claim 2, wherein said high molecular film further comprises a photoinitiator.

4. The liquid crystal display device as claimed in claim 1, wherein said high molecular film has a thickness equal to or less than a cell gap.

5. A liquid crystal display device wherein a counter electrode and a pixel electrode are formed on a transparent insulating substrate, comprising:

a first transparent insulating substrate having (a) a high molecular film formed on the pixel electrode and the counter electrode, preventing the fringe field in the in-plane switching mode, (b) a conductor inserted in said high molecular films, the conductor being electrically contacted with said pixel electrode and said counter electrode, and having the same height as said high molecular film, and an alignment film formed on said substrate between said counter electrode and said pixel electrode;

a second transparent insulating substrate arranged parallel to the first transparent insulating substrate; and

a liquid crystal material disposed between the first and second transparent insulating substrates, for selectively transmitting light in response to a prescribed input.

6. The liquid crystal display device as claimed in claim 5, wherein said high molecular film further comprises a photoinitiator.

7. The liquid crystal display device as claimed in claim 5, wherein said high molecular film is a photosensitive insulator.

8. The liquid crystal display device as claimed in claim 5, wherein said high molecular film is a photosensitive conductor.

9. The liquid crystal display device as claimed in claim 5, wherein said high molecular film has a thickness equal to or less than a cell gap.

10. The liquid crystal display device as claimed in claim 5, wherein said conductor is indium tin oxide.

11. A method for fabricating a liquid crystal display device, the method comprising the steps of:

providing a transparent insulating substrate;

forming a counter electrode pattern and a gate electrode pattern on the transparent substrate;

forming a first conductive high molecular film on the counter electrode pattern, preventing the fringe field in the in-plane switching mode;

forming a insulating layer on the whole surface of the substrate;

forming a pixel electrode pattern on a selected portion of the insulating layer;

forming a second conductive high molecular film on the pixel electrode pattern, preventing the fringe field in the in-plane switching mode; and

forming an alignment layer on the whole surface of the substrate.

12. The method as claimed in claim 11, wherein said step for forming said first conductive high molecular film and said second conductive high molecular film, each comprises the steps of:

coating a film on the whole surface of the substrate, the film comprising a conductive high molecular material mixed with a solvent;

curing the film;

forming a photoresist mask pattern on portions of the film over the counter electrode and the pixel electrode;

removing exposed portions of the film using said photoresist mask pattern; and

removing said photoresist mask pattern.

13. The method as claimed in claim 12, wherein said first and second high molecular films are respectively formed by a chemical synthesis of one or more materials selected from a group consisting of polyacetylene, polyaniline, p-phenylene, polypryrrole, polythiophene and p-phenylenevinylene.

14. The method as claimed in claim 11, wherein said step of forming first and second conductive high molecular films, comprises the steps of:

coating a film on the whole surface of the substrate, the film comprising a conductive high molecular material mixed with a solvent;

curing the film;

irradiating ultraviolet rays on portions of the film over the counter electrode and the pixel electrode; and

removing the irradiated portions of the film.

15. The method as claimed in claim 14, wherein said first and second high molecular films are respectively formed by a chemical synthesis of one or more materials selected from a group consisting of polyacetylene, polyaniline, p-phenylene, polypryrrole, polythiophene and p-phenylenevinylene.

16. The method as claimed in claim 11, wherein said high molecular films have a thickness equal to or less than a cell gap.

17. A method for fabricating a liquid crystal display device, the method comprising the steps of:

providing a transparent insulating substrate;

forming a counter electrode pattern and a gate electrode pattern on the transparent substrate;

forming an insulating layer on the whole surface of the transparent substrate;

forming a channel layer on a portion of the insulating layer over the gate electrode pattern;

forming a pixel electrode pattern on a selected portion of the insulating layer;

removing the insulating layer on the counter electrode;

forming conductive high molecular film patterns on the pixel electrode pattern and the counter electrode pattern, preventing the fringe field in the in-plane switching mode; and

forming an alignment layer on the whole surface of the substrate.

18. The method as claimed in claim 17, wherein said step of forming conductive high molecular film patterns, comprises the steps of:

coating a film on the whole surface of the substrate, the film comprising a conductive high molecular material mixed with a solvent;

curing the film;

forming a photoresist mask pattern on portions of film over the counter electrode and the pixel electrode;

removing exposed portions of the film using said photoresist mask pattern; and

removing said photoresist mask pattern.

19. The method as claimed in claim 18, wherein said high molecular film patterns are respectively formed by a chemical synthesis of one or more materials selected from a group consisting of polyacetylene, polyaniline, p-phenylene, polypryrrole, polythiophene and p-phenylenevinylene.

20. The method as claimed in claim 17, wherein said step of forming conductive high molecular film patterns, comprises the steps of:

coating a film on the whole surface of the substrate, the film comprising a conductive high molecular material mixed with a solvent;

curing the film;

irradiating ultraviolet ray on portions of film over the counter electrode and the pixel electrode; and

removing the irradiated portions of the film.

21. The method as claimed in claim 20, wherein said high molecular film patterns are respectively formed by a chemical synthesis of one or more materials selected from a group consisting of polyacetylene, polyaniline, p-phenylene, polypryrrole, polythiophene and p-phenylenevinylene.

22. The method as claimed in claim 17, wherein said high molecular film patterns have a thickness equal to or less than a cell gap.

23. A method for fabricating a liquid crystal display device, the method comprising the steps of:

providing a transparent insulating substrate;

forming a counter electrode pattern and a gate electrode pattern on the transparent substrate;

forming an insulating layer on the whole surface of the transparent substrate;

forming a channel layer on a portion of the insulating layer over the gate electrode pattern;

forming a pixel electrode pattern on a selected portion of the insulating layer;

removing the insulating layer on the counter electrode;

forming photosensitive high molecular film patterns exposing a core portion of the pixel electrode pattern and a core portion of the counter electrode pattern at a selected height or the whole surface, preventing the fringe field in the in-plane switching mode;

filling the exposed portions with a conductor;

removing said high molecular film at portions except the upper portion of the counter electrode and the upper portion of the pixel electrode; and

forming an alignment layer on the whole surface of the substrate.

24. The method as claimed in claim 23, wherein said step of forming said high molecule film, comprises the steps of:

coating a film on the whole surface of the substrate, the film comprising a conductive high molecular material mixed with a solvent;

curing the film;

removing the film by exposure to light and by a development process, except the portions of the film existing on the upper portion of the counter electrode and the upper portion of the pixel electrode.

25. The method as claimed in claim 23, wherein said high molecular film has a thickness equal to or less than a cell gap.

26. The method as claimed in claim 23, further comprising the step of removing the alignment layer on the surface of the high molecular film and the conductor.

27. The method as claimed in claim 23, wherein said conductor is induim tin oxide.