Liquid crystal display device and method for manufacturing the same

• US 8,654,292 B2
• Filed: 05/13/2010
• Issued: 02/18/2014
• Est. Priority Date: 05/29/2009
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Kubota, Daisuke, Yamashita, Akio, Ishitani, Tetsuji, Tamura, Tomohiro
• Primary Examiner(s): KIANNI, KAVEH C
• Application Number:
  US12/779,604
• Publication Number:
  US 20100302492A1
• Time in Patent Office: 1,377 Days
• Field of Search: None
• US Class Current: 349/138
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133707 Structures for producing distorted electric fields, e.g. bumps, protrusions, recesses, slits in pixel electrodes
• CPC Class Codes: G02F 1/1343 Electrodes reflective electrodes G02F1/133553
• 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 1/134372 for fringe field switching [FFS] where the common electrode is not patterned
• CPC Class Codes: G02F 1/1345 Conductors connecting electrodes to cell terminals
• CPC Class Codes: G02F 1/13793 Blue phases
• CPC Class Codes: G02F 2202/023 curable
• CPC Class Codes: G02F 2202/103 a-Si
• CPC Class Codes: G02F 2202/104 poly-Si
• CPC Class Codes: G02F 2202/105 single crystal Si
• CPC Class Codes: H01L 27/1225 with semiconductor materials not belonging to the group IV of the periodic table, e.g. InGaZnO
• CPC Class Codes: H01L 29/04 characterised by their crystalline structure, e.g. polycrystalline, cubic or particular orientation of crystalline planes characterised by physical imperfections H01L29/30
• CPC Class Codes: H01L 29/78696 characterised by the structure of the channel, e.g. multichannel, transverse or longitudinal shape, length or width, doping structure, or the overlap or alignment between the channel and the gate, the source or the drain, or the contacting structure of the channel H01L29/78612 takes precedence; transistors having a drain offset region or a lightly doped drain [LDD] H01L29/78621

Abstract

A liquid crystal display device using a liquid crystal exhibiting a blue phase and having a novel structure, and a method for manufacturing the liquid crystal display device. A plurality of structure bodies (also referred to as ribs, protrusions, or projecting portions) are formed over the same substrate, and a pixel electrode and an electrode (a common electrode at a fixed potential) corresponding to the pixel electrode are formed thereover. An electric field is applied to the liquid crystal layer exhibiting a blue phase by using the pixel electrode that has an inclination and the electrode corresponding to the pixel electrode, which also has an inclination. A shorter distance between the adjacent structure bodies allows a strong electric field to be applied to the liquid crystal layer, which results in a reduction in power consumption for driving the liquid crystal.

Claims

1. A liquid crystal display device comprising:

a first substrate;

a first structure body, a second structure body, and a third structure body over the first substrate, wherein each of the first to third structure bodies protrudes from the first substrate;

a first electrode layer over the first structure body, the second structure body, and the third structure body, wherein the first electrode layer is electrically connected to one of source and drain electrode layers of a transistor;

an insulating layer over the first electrode layer, the insulating layer protruding from the first substrate due to the protrusion of each of the first to third structure bodies;

a second electrode layer over the insulating layer, the second electrode layer overlapping a side surface of the first structure body and a side surface of the third structure body;

a liquid crystal layer over the second electrode layer, the liquid crystal layer being capable of exhibiting a blue phase; and

a second substrate over the liquid crystal layer,

wherein the second electrode layer includes an opening,

wherein the second structure body is provided between the first structure body and the third structure body, and

wherein the opening of the second electrode layer overlaps the second structure body.

2. The liquid crystal display device according to claim 1,

wherein the first structure body, the second structure body, and the third structure body comprise an organic resin material.

3. The liquid crystal display device according to claim 1,

wherein each of the first to third structure bodies protrude within the liquid crystal layer.

4. The liquid crystal display device according to claim 1, further comprising a third electrode layer between the liquid crystal layer and the second substrate,

wherein the third electrode layer is configured to be applied with a fixed potential.

5. The liquid crystal display device according to claim 1,

wherein the first electrode layer is directly connected to one of the source and the drain electrode layers of the transistor, and

wherein the second electrode layer is configured to be applied with a fixed potential.

6. The liquid crystal display device according to claim 1, further comprising a third electrode layer between the liquid crystal layer and the second substrate,

wherein the third electrode layer is configured to be applied with a fixed potential, and

wherein the third electrode layer overlaps the second electrode layer with the liquid crystal layer interposed therebetween.

7. The liquid crystal display device according to claim 1,

wherein the insulating layer comprises an inorganic insulating material.

8. The liquid crystal display device according to claim 1,

wherein the first structure body, the second structure body, and the third structure body are arranged at a regular interval.

9. The liquid crystal display device according to claim 1,

wherein the insulating layer is in direct contact with the first electrode layer and the second electrode layer.

10. The liquid crystal display device according to claim 1,

wherein the second electrode layer is in direct contact with the liquid crystal layer.

11. The liquid crystal display device according to claim 1,

wherein the first to third structure bodies are in the same plane with the transistor.

12. The liquid crystal display device according to claim 1,

wherein the second electrode protrudes from the first substrate due to the protrusion of the first to third structure bodies.

13. The liquid crystal display device according to claim 1,

wherein the first to third structure bodies do not overlap with the transistor.

14. A liquid crystal display device comprising:

a first substrate;

first to third structure bodies over the first substrate, wherein each of the first to third structure bodies is arranged to protrude from the first substrate;

a first electrode layer over the first to third structure bodies, wherein the first electrode layer is electrically connected to one of source and drain electrode layers of a transistor;

an insulating layer over the first electrode layer, the insulating layer being arranged to protrude from the first substrate due to the protrusion of each of the first to third structure bodies;

a second electrode layer over the insulating layer;

a liquid crystal layer over the second electrode layer, the liquid crystal layer being capable of exhibiting a blue phase; and

a second substrate over the liquid crystal layer.

15. The liquid crystal display device according to claim 14,

wherein the first to third structure bodies comprise an organic resin material.

16. The liquid crystal display device according to claim 14,

wherein each of the first to third structure bodies protrude within the liquid crystal layer.

17. The liquid crystal display device according to claim 14, further comprising a third electrode layer between the liquid crystal layer and the second substrate,

wherein the third electrode layer is configured to be applied with a fixed potential.

18. The liquid crystal display device according to claim 14,

wherein the first electrode layer is directly connected to one of the source and the drain electrode layers of the transistor, and

wherein the second electrode layer is configured to be applied with a fixed potential.

19. The liquid crystal display device according to claim 14, further comprising a third electrode layer between the liquid crystal layer and the second substrate,

wherein the third electrode layer is configured to be applied with a fixed potential, and

wherein the third electrode layer overlaps the second electrode layer with the liquid crystal layer interposed therebetween.

20. The liquid crystal display device according to claim 14,

wherein the first to third structure bodies are arranged at a regular interval.

21. The liquid crystal display device according to claim 14,

wherein the second electrode layer includes an opening which overlaps the second structure body, and

wherein the second structure body is located between the first structure body and the third structure body.

22. The liquid crystal display device according to claim 14,

wherein the insulating layer is in direct contact with the first electrode layer and the second electrode layer.

23. The liquid crystal display device according to claim 14,

wherein the second electrode layer is in direct contact with the liquid crystal layer.

24. The liquid crystal display device according to claim 14,

wherein the first to third structure bodies are in the same plane with the transistor.

25. The liquid crystal display device according to claim 14,

wherein the second electrode protrudes from the first substrate due to the protrusion of the first to third structure bodies.

26. The liquid crystal display device according to claim 14,

wherein the first to third structure bodies do not overlap with the transistor.