Liquid crystal cell and a method for fabricating that

• US 6,091,471 A
• Filed: 12/30/1996
• Issued: 07/18/2000
• Est. Priority Date: 12/29/1995
• Status: Expired due to Fees

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Nam, Mi Sook, Kim, Jong Hyun, Yoon, Ki Hyuk, Kim, Kyeong Jin, Woo, Joung Won, Choi, Yoo Jin
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): NGUYEN, DUNG T
• Application Number:
  US08/777,126
• Time in Patent Office: 1,296 Days
• Field of Search: 349/124, 349/129, 349/128, 349/123, 349/125, 349/126, 349/191
• US Class Current: 349/124
• CPC Class Codes: G02F 1/133753 with different alignment orientations or pretilt angles on a same surface, e.g. for grey scale or improved viewing angle
• 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
• CPC Class Codes: G02F 1/133784 by rubbing
• CPC Class Codes: G02F 1/133788 by light irradiation, e.g. linearly polarised light photo-polymerisation
• CPC Class Codes: G02F 1/1393 the birefringence of the liquid crystal being electrically controlled, e.g. ECB-, DAP-, HAN-, PI-LC cells G02F1/1396, G02F1/141 take precedence
• CPC Class Codes: G02F 1/1396 the liquid crystal being selectively controlled between a twisted state and a non-twisted state, e.g. TN-LC cell G02F1/141 takes precedence

Abstract

A LC cell is manufactured by the method including the steps of: rubbing a first alignment layer coating a first substrate, such that the first alignment layer has a first pretilt angle associated therewith; exposing said second alignment layer coating a first substrate to light such that said second alignment layer has at least one second pretilt angle associated therewith; and providing a liquid crystal material between said first and second substrates. The materials for the first and second alignment layers include a polyimide and a polysiloxane based material.

Claims

1. A method of manufacturing a liquid crystal display, comprising the steps of:

providing a first alignment layer on a first substrate;

rubbing said first alignment layer such that said first alignment layer has a first pretilt angle associated therewith;

providing a second alignment layer on a second substrate;

exposing said second alignment layer to light such that said second alignment layer includes a plurality of pretilt angles associated therewith, said plurality of pretilt angles being oriented in a plurality of pretilt directions, said light being incident substantially perpendicular to said second alignment layer, and further exposing additional light to select one of said plurality of pretilt angles; and

providing a liquid crystal material between said first and second substrates.

2. A method in accordance with claim 1, wherein said additional light comprises unpolarized light.

3. A method in accordance with claim 2, wherein said unpolarized additional light is obliquely incident to the second alignment layer.

4. A method of manufacturing a liquid crystal display, comprising the steps of:

providing a first alignment layer on a first substrate;

rubbing said first alignment layer such that said alignment layer has a first pretilt angle associated therewith;

providing a second alignment layer on a second substrate;

exposing said second alignment layer to light such that said second alignment layer includes a plurality of pretilt angles associated therewith, said plurality of pretilt angles being oriented in a plurality of pretilt directions; and

exposing said second alignment layer to a polarized light in the perpendicular direction;

exposing said second alignment layer to a nonpolarized light in the oblique direction; and

providing a liquid crystal material between said first and second substrates.

5. A method of manufacturing a liquid crystal display, comprising the steps of:

providing a first alignment layer on a first substrate;

rubbing said first alignment layer such that said alignment layer has a first pretilt angle associated therewith;

providing a second alignment layer on a second substrate;

exposing said second alignment layer to light such that said second alignment layer includes a plurality of pretilt angles associated therewith, said plurality of pretilt angles being oriented in a plurality of pretilt directions;

exposing said second alignment layer to a nonpolarized light in the oblique direction;

exposing said second alignment layer to a polarized light in the perpendicular direction; and

providing a liquid crystal material between said first and second substrates.

6. A method of manufacturing a liquid crystal display, comprising the steps of:

providing a first alignment layer on a first substrate;

rubbing said first alignment layer such that said alignment layer has a first pretilt angle associated therewith;

providing a second alignment layer on a second substrate;

exposing said second alignment layer to light such that said second alignment layer includes a plurality of pretilt angles associated therewith, said plurality of pretilt angles being oriented in a plurality of pretilt directions;

exposing said second alignment layer to a first light such that said plurality of pretilt angles are associated with said second alignment layer, said plurality of pretilt angles being oriented in respective pretilt directions,

exposing a first portion of said second alignment layer to a second light so as to select one of said pretilt angles associated with said first portion oriented in a first direction;

exposing a second portion of said second alignment layer to a third light so as to select one of said pretilt angles associated with said second portion oriented in a second direction; and

providing a liquid crystal material between said first and second substrates.

7. A method in accordance with claim 6, wherein said first light includes linearly polarized light.

8. A method in accordance with claim 6, wherein said first light is incident substantially perpendicular to a surface of said second alignment layer.

9. A method in accordance with claim 6, wherein said second light, said third light, or both said second and third lights include unpolarized light.

10. A method in accordance with claim 9, wherein said second light, said third light, and both said second and third lights are incident obliquely to said surface of said second alignment layer.

11. A method of manufacturing a liquid crystal display, comprising the steps of:

providing a first alignment layer on a first substrate;

rubbing said first alignment layer such that said alignment layer has a first pretilt angle associated therewith;

providing a second alignment layer on a second substrate;

exposing said second alignment layer to light such that said second alignment layer includes a plurality of pretilt angles associated therewith, said plurality of pretilt angles being oriented in a plurality of pretilt directions;

providing a third alignment layer on a portion of said first alignment layer;

rubbing said third alignment layer such that said third alignment layer has a third pretilt angle associated therewith; and

providing a liquid crystal material between said first and second substrates.

12. A method in accordance with claim 11, wherein said third alignment layer has a pretilt angle forming characteristics differing than that of the first alignment layer.

13. A method in accordance with claim 11, wherein said third pretilt angle has a magnitude greater than said first pretilt angle.

14. A method of manufacturing a liquid crystal display, comprising the steps of:

providing a first alignment layer on a first substrate;

rubbing said first alignment layer such that said alignment layer has a first pretilt angle associated therewith;

providing a second alignment layer on a second substrate;

exposing said second alignment layer to light such that said second alignment layer includes a plurality of pretilt angles associated therewith, said plurality of pretilt angles being oriented in a plurality of pretilt directions;

exposing a first portion of said second alignment layer to a first dose of a first light such that a first plurality of pretilt angles having respective pretilt directions are associated with said first portion of said second alignment layer,

exposing a second portion of said second alignment layer to a second dose of said first light such that a second plurality of pretilt angles having respective pretilt directions are associated with said second portion of said second alignment layer; and

providing a liquid crystal material between said first and second substrates.

15. A method in accordance with claim 14, further comprising the steps of:

exposing said first portion of said second alignment layer to a first dose of a second light to select one of said pretilt angles associated with said first portion of said second alignment layer; and

exposing said second portion of said second alignment layer to a second dose of said second light to select ones of said pretilt angles associated with said second portion of said second alignment layer.

16. A method in accordance with claim 15, wherein said second light includes unpolarized light.

17. A method in accordance with claim 15, wherein said second light is incident obliquely to said surface of said second alignment layer.

18. A method in accordance with claim 15, wherein said second light is supplied to said second alignment layer through a plate having a first part aligned with said first portion of said second alignment and having a first transmissivity, and a second part aligned with said second portion of said second alignment layer and having a second transmissivity.

19. A method in accordance with claim 14, wherein said first light includes linearly polarized light.

20. A method in accordance with claim 14, wherein said first light is incident substantially perpendicular to said surface of said second alignment layer.

21. A method in accordance with claim 14, wherein said first plurality of pretilt angles each have a magnitude greater than a magnitude of each of said second plurality of pretilt angles.

22. A method in accordance with claim 14, wherein said first light is supplied to said second alignment layer through a plate having a first part aligned with said first portion of said substrate and having a first transmissivity, and a second part aligned with said second portion of said second alignment layer and having a second transmissivity.

23. A method of manufacturing a liquid crystal display, comprising the steps of:

providing a first alignment layer on a first substrate;

rubbing said first alignment layer such that said alignment layer has a first pretilt angle associated therewith;

providing a second alignment layer on a second substrate;

exposing said second alignment layer to light such that said second alignment layer includes a plurality of pretilt angles associated therewith, said plurality of pretilt angles being oriented in a plurality of pretilt directions;

exposing a first portion of said second alignment layer to a first light such that a first pretilt angle oriented in a first direction is associated with said first portion of said second alignment layer;

exposing a second portion of said second alignment layer to a second light such that a second pretilt angle oriented in a second direction is associated with said second portion of said second alignment layer,

exposing a third portion of said second alignment layer to a third light such that a third pretilt angle oriented in a third direction is associated with said third portion of said second alignment layer;

exposing a fourth portion of said second alignment layer to a fourth light such that a fourth pretilt angle oriented in a fourth direction is associated with said fourth portion of said second alignment layer; and

providing a liquid crystal material between said first and second substrates.

24. A method in accordance with claim 23, wherein at least one of said first, second, third, and fourth lights include unpolarized light.

25. A method in accordance with claim 24, wherein at least one of said first, second, third, and fourth lights is incident obliquely to said surface of said second alignment layer.

26. A method of manufacturing a liquid crystal display, comprising the steps of:

providing a first alignment layer on a first substrate;

rubbing said first alignment layer such that said alignment layer has a first pretilt angle associated therewith;

providing a second alignment layer on a second substrate;

exposing said second alignment layer to light such that said second alignment layer includes a plurality of pretilt angles associated therewith, said plurality of pretilt angles being oriented in a plurality of pretilt directions;

exposing a first portion of said second alignment layer to a first polarized light in the first perpendicular direction;

exposing a second portion of said second alignment layer to a second polarized light in the second perpendicular direction; and

providing a liquid crystal material between said first and second substrates.

27. A method in accordance with claim 26, wherein the exposing step is further comprising the steps of:

exposing a first portion of said second alignment layer to a first unpolarized light in the first oblique direction; and

exposing a second portion of said second alignment layer to a second unpolarized light in the second oblique direction.

28. A method in accordance with claim 26, wherein the exposing step is further comprising the steps of:

exposing a first area of a first portion of said second alignment layer to a first unpolarized light in a first oblique direction;

exposing a second area of a first portion of said second alignment layer to a second unpolarized light in a second oblique direction and;

exposing a first area of a second portion of said second alignment layer to a third unpolarized light in a third oblique direction; and

exposing a second area of a second portion of said second alignment layer to a fourth unpolarized light in a fourth oblique direction.