DISPLAY DEVICE

• US 20120327350A1
• Filed: 01/12/2012
• Published: 12/27/2012
• Est. Priority Date: 06/24/2011
• Status: Active Grant

• Current Assignee: Industrial Technology Research Institute, University of Central Florida Research Foundation Inc. (State University System of Florida)
• Original Assignee: Industrial Technology Research Institute, University of Central Florida (State University System of Florida)
• Inventors: Chang, Yu-Pei, Yang, Ming-Huan, Tsai, Chen-Chu, Jiao, Meizi, Wu, Shin-Tson, Li, Yan
• Granted Patent: US 8,736,800 B2
• Time in Patent Office: Days
• US Class Current: 349/139
• CPC Class Codes: G02F 1/133371 Cells with varying thickness of the liquid crystal layer
• 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 1/134363 for applying an electric field parallel to the substrate, i.e. in-plane switching [IPS]
• CPC Class Codes: G02F 1/13793 Blue phases

Abstract

A display device includes a first substrate, at least a first protrusion, a first electrode, a second substrate, at least a second protrusion, a second electrode and a display medium. The first protrusion is disposed on the first substrate. The first electrode is disposed on the first protrusion. The second substrate is disposed opposite to the first substrate. The second protrusion is disposed on the second substrate. The second electrode is disposed on the second protrusion, wherein the first electrode and the second electrode are displaced in a horizontal direction so as to form a lateral electric field therebetween. The display medium is sandwiched between the first and the second substrates.

Claims

1. A display device comprising:

a first substrate;

at least one first protrusion on the first substrate;

a first electrode on the first protrusion;

a second substrate opposite to the first substrate;

at least one second protrusion on the second substrate;

a second electrode on the second protrusion, wherein the first electrode and the second electrode are displaced in a horizontal direction to each other so as to form a lateral electric field therebetween, wherein the smallest gap between the first electrode and the second electrode in a vertical direction ranges from −

100 μ

m to 100 μ

m; and

a display medium sandwiched between the first and the second substrates.

2. The display device of claim 1, wherein the smallest gap between the first electrode and the second electrode in the vertical direction ranges from 0.5 μ

m to 10 μ

m.

3. The display device of claim 1, wherein the first protrusion and the second protrusion respectively have a width ranged from 0.2 μ

m to 100 μ

m, horizontal gaps between adjacent first protrusions and between adjacent second protrusions ranged from 0.2 μ

m to 100 μ

m, and thicknesses of the first protrusion and the second protrusion ranged from 0.2 μ

m to 100 μ

m.

4. The display device of claim 1, wherein the first protrusion and the second protrusion have the same or different shapes from a cross-sectional view.

5. The display device of claim 1 further comprising:

a first linear or circular polarizer disposed on the first substrate;

a second linear or circular polarizer disposed on the second substrate; and

at least one retardation film disposed between the first and second linear or circular polarizers,

wherein the retardation film is a biaxial film with its Nz factor (Nz=(nx−

nz)/(nx−

ny)) at about 0.5, and the in-plane phase retardation R0=d×

(nx−

ny) between 100 nm and 300 nm.

6. The display device of claim 1, wherein the display medium comprises a blue phase liquid crystal (BPLC), a polymer-stabilized BPLC composite or an optically isotropic liquid crystal composite.

7. A display device comprising:

a first substrate;

a plurality of first protrusions on the first substrate, each first protrusion having a first side wall and a second side wall;

a first electrode, on the first side wall of each first protrusion;

a second electrode, on the second side wall of each first protrusion, wherein a lateral electric field is formed between the first electrode on each first protrusion and the second electrode on the adjacent first protrusion;

a second substrate opposite to the first substrate;

a plurality of second protrusions on the second substrate, each second protrusion having a third side wall and a fourth side wall;

a third electrode, on the third side wall of each second protrusion;

a fourth electrode, on the fourth side wall of each second protrusion, wherein a lateral electric field is formed between the third electrode on each second protrusion and the fourth electrode on the adjacent second protrusion; and

a display medium sandwiched between the first and the second substrates.

8. The display device of claim 7, wherein the first protrusions and the second protrusions are complementarily aligned.

9. The display device of claim 7, wherein the first and second protrusions have a width ranged from 0.2 μ

m to 100 μ

m, the horizontal gaps between adjacent first protrusions and between adjacent second protrusions ranged from 0.2 μ

m to 100 μ

m, and thicknesses of the first and second protrusions ranged from 0.2 μ

m to 100 μ

m.

10. The display device of claim 7, wherein shapes of the first and second protrusions from the cross-sectional view are the same or different.

11. The display device of claim 7, wherein the first electrode is aligned to the third electrode in a vertical direction, and the second electrode is aligned to the fourth electrode in the vertical direction.

12. The display device of claim 7, wherein the first electrode is aligned to the fourth electrode in a vertical direction, and the second electrode is aligned to the third electrode in the vertical direction.

13. The display device of claim 7, wherein each first protrusion has a top surface and a bottom surface smaller than the top surface, and each second protrusion has a top surface and a bottom surface smaller than the top surface.

14. The display device of claim 7 further comprising:

a first linear or circular polarizer disposed on the first substrate;

a second linear or circular polarizer disposed on the second substrate; and

at least one retardation film disposed between the first and second linear or circular polarizers,

wherein the retardation film is a biaxial film with its Nz factor (Nz=(nx−

nz)/(nx−

ny)) at about 0.5, and the in-plane phase retardation R0=d×

(nx−

ny) between 100 nm and 300 nm.

15. The display device of claim 7, wherein the display medium comprises a blue phase liquid crystal (BPLC), a polymer-stabilized BPLC composite or an optically isotropic liquid crystal composite.

16. A display device comprising:

a first substrate;

a plurality of first protrusions on the first substrate, each first protrusion having a first side wall and a second side wall;

a first electrode, on the first side wall of each first protrusion;

a second electrode, on the second side wall of each first protrusion, wherein a lateral electric field is formed between the first electrode on each first protrusion and the second electrode on the adjacent first protrusion;

a plurality of second protrusions disposed on the first protrusions, each second protrusion having a third side wall and a fourth side wall;

a third electrode, on the third side wall of each second protrusion and contacts with the first electrode on the first protrusions;

a fourth electrode, on the fourth side wall of each second protrusion and contacts with the second electrode on the first protrusions, wherein a lateral electric field is formed between the third electrode on each second protrusion and the fourth electrode on the adjacent second protrusion;

a second substrate opposite to the first substrate; and

a display medium sandwiched between the first and the second substrates.

17. The display device of claim 16, wherein the first protrusions and the second protrusions are complementarily aligned.

18. The display device of claim 16, wherein the first and second protrusions have a width ranged from 0.2 μ

m to 100 μ

m, horizontal gaps between adjacent first protrusions and between adjacent second protrusions ranged from 0.2 μ

m to 100 μ

m, and thicknesses of the first and second protrusions ranged from 0.2 μ

m to 100 μ

m.

19. The display device of claim 16, wherein shapes of the first and second protrusions from the cross-sectional view are the same or different.

20. The display device of claim 16 further comprising:

a first linear or circular polarizer disposed on the first substrate;

a second linear or circular polarizer disposed on the second substrate; and

at least one retardation film disposed between the first and second linear or circular polarizers,

wherein the retardation film is a biaxial film with its Nz factor (Nz=(nx−

nz)/(nx−

ny)) at about 0.5, and the in-plane phase retardation R0=d×

(nx−

ny) between 100 nm and 300 nm.

21. The display device of claim 16, wherein the display medium comprises a blue phase liquid crystal (BPLC), a polymer-stabilized BPLC composite, or an optically isotropic liquid crystal composite.

22. A display device comprising:

a first substrate;

at least one first bump electrode on the first substrate;

a second substrate opposite to the first substrate;

at least one second bump electrode on the second substrate, wherein the first bump electrode and the second bump electrode are displaced in a horizontal direction so as to form a lateral electric field therebetween, and a overlapping height between the first bump electrode and the second bump electrode in the vertical direction is larger than 0 and smaller than a cell gap between the first substrate and the second substrate; and

a display medium sandwiched between the first and the second substrates.

23. The display device of claim 22, wherein the first bump electrode and second bump electrode have a width ranged from 0.2 μ

m to 100 μ

m, horizontal gaps between adjacent first bump electrodes and between adjacent second bump electrodes ranged from 0.2 μ

m to 100 μ

m, and thicknesses of the first bump electrode and the second bump electrode ranged from 0.2 μ

m to 100 μ

m.

24. The display device of claim 22, wherein the first bump electrode and the second bump electrode have the same or different shapes from a cross-sectional view.

25. The display device of claim 22 further comprising:

a first linear or circular polarizer disposed on the first substrate;

a second linear or circular polarizer disposed on the second substrate; and

at least one retardation film disposed between the first and second linear or circular polarizers,

wherein the retardation film is a biaxial film with its Nz factor (Nz=(nx−

nz)/(nx−

ny)) at about 0.5, and the in-plane phase retardation R0=d×

(nx−

ny) between 100 nm and 300 nm.

26. The display device of claim 22, wherein the display medium comprises a blue phase liquid crystal (BPLC), a polymer-stabilized BPLC composite, or an optically isotropic liquid crystal composite.