LIQUID CRYSTAL DISPLAY DEVICE AND FABRICATING METHOD THEREOF

• US 20140184984A1
• Filed: 12/17/2013
• Published: 07/03/2014
• Est. Priority Date: 01/02/2013
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: KIM, Kyeong Jin, HWANG, Jung Im, JEON, Ji Na, HA, Kyung Su
• Granted Patent: US 9,366,920 B2
• Time in Patent Office: Days
• US Class Current: 349/61
• CPC Class Codes: G02F 1/1334 based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals
• 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 2202/36 Micro- or nanomaterials

Abstract

Provided are a liquid crystal display (LCD) device and fabricating method thereof. The liquid crystal display device, including a liquid crystal panel, includes: a first substrate, including: a pixel electrode, and a common electrode separated from the pixel electrode, a ratio of a width of the pixel electrode to a distance between the pixel electrode and the common electrode being in a range of about 1:1 to 1:7, and a nanocapsule liquid crystal layer formed on the first substrate, the nanocapsule liquid crystal layer including: a buffer material, and nanocapsules, each filled with liquid crystal molecules.

Claims

1. A liquid crystal display (LCD) device, comprising a liquid crystal panel, comprising:

a first substrate, comprising;

a pixel electrode; and

a common electrode separated from the pixel electrode, a ratio of a width of the pixel electrode to a distance between the pixel electrode and the common electrode being in a range of about 1;

1 to 1;

7; and

a nanocapsule liquid crystal layer formed on the first substrate, the nanocapsule liquid crystal layer comprising;

a buffer material; and

nanocapsules, each filled with liquid crystal molecules.

2. The liquid crystal display device of claim 1, wherein a diameter of each of the nanocapsules is in a range of about 1 nm to 320 nm.

3. The liquid crystal display device of claim 2, wherein the diameter of each of the nanocapsules is in a range of about 30 nm to 100 nm.

4. The liquid crystal display device of claim 1, wherein the nanocapsules comprise 25 vol % to 65 vol % of the nanocapsule liquid crystal layer.

5. The liquid crystal display device of claim 1, wherein a dielectric constant Δ

∈

of the liquid crystal molecules is in a range of about 35 to 100.

6. The liquid crystal display device of claim 1, wherein a refractive index Δ

n of the liquid crystal molecules is in a range of about 0.18 to 0.30.

7. The liquid crystal display device of claim 1, wherein a difference between an average refractive index Δ

n of the liquid crystal molecules and a refractive index Δ

n of the buffer layer is about 0.1.

8. The liquid crystal display device of claim 1, further comprising:

a second substrate opposed to the first substrate with the nanocapsule liquid crystal layer therebetween;

a gate line and a data line on the first substrate that cross perpendicularly to each other and define a pixel region;

a thin film transistor at an intersection of the gate line and the data line; and

a color filter layer on the second substrate.

9. The liquid crystal display device of claim 1, further comprising:

a second substrate opposed to the first substrate with the nanocapsule liquid crystal layer therebetween;

a gate line and a data line on the first substrate that cross perpendicularly to each other and define a pixel region;

a thin film transistor at an intersection of the gate and data lines; and

a color filter layer on the first substrate, the first substrate being provided with the thin film transistor.

10. The liquid crystal display device of claim 1, further comprising:

a polarizing plate in direct contract with the nanocapsule liquid crystal layer; and

a backlight unit on a rear surface of the liquid crystal panel and configured to;

irradiate light onto the liquid crystal panel; and

emit red, green, and blue light.

11. The liquid crystal display device of claim 1, wherein the liquid crystal panel comprises one of:

a flexible panel and a curved panel.

12. The liquid crystal display device of claim 1, wherein the pixel electrode and the common electrode have a same width.

13. The liquid crystal display device of claim 1, wherein the pixel electrode and the common electrode comprise a protrusive structure.

14. The liquid crystal display device of claim 13, wherein the protrusive structure comprises:

at least one protrusion layer; and

at least one metal layer.

15. The liquid crystal display device of claim 13, wherein respective heights of the pixel electrode and the common electrode are in a range of about 0.5 μ

m to 5.0 μ

m.

16. The liquid crystal display device of claim 1, wherein a thickness of the nanocapsule liquid crystal layer is in a range of about 1 μ

m to 10 μ

m.

17. The liquid crystal display device of claim 1, further comprising:

a gate line on the first substrate;

a data line that crosses the gate line and defines a pixel region;

a power supply line that crosses the gate line and is separated from the data line;

a first thin film transistor connected to the gate line and the data line; and

a second thin film transistor connected to the gate line and the power supply line,

wherein the first thin film transistor is configured to supply the pixel electrode with a level-shifted data voltage, and

wherein the second thin film transistor is configured to supply the common electrode with a level-shifted common voltage in a level-shifting polarity opposite to the data voltage.

18. The liquid crystal display device of claim 17, wherein:

the data line, the power supply line, the pixel electrode and the common electrode are in a structure that is symmetrically bent about a central portion of the pixel region; and

wherein the pixel region has at least two domains.

19. A method of fabricating a liquid crystal display (LCD) device, the method comprising:

forming a thin film transistor on a first substrate, comprising;

forming a pixel electrode connected to the thin film transistor; and

forming a common electrode which is separated from the pixel electrode;

forming a nanocapsule liquid crystal layer on the first substrate; and

providing a liquid crystal panel,

wherein the nanocapsule liquid crystal layer comprises;

a buffer material; and

nanocapsules each filled with liquid crystal molecules, and

wherein a ratio of a width of the pixel electrode to a distance between the pixel electrode and the common electrode is in a range of about 1;

1 to 1;

7.

20. The method of claim 19, wherein the pixel electrode and the common electrode have a same width.

21. The method of claim 19, wherein the pixel electrode and the common electrode are formed in a protrusive structure.

22. The method of claim 21, wherein respective heights of the pixel electrode and the common electrode are formed in a range of about 0.5 μ

m to 5.0 μ

m.

23. The method of claim 19, wherein a thickness of the nanocapsule liquid crystal layer is formed in a range of about 1 μ

m to 10 μ

m.

24. The method of claim 19, wherein the formation of the thin film transistor comprises:

forming a gate line, a first gate electrode, and a second gate electrode on the first substrate;

forming a gate insulation film on the first substrate provided with the gate line, the first gate electrode, and the second gate electrode;

forming a semiconductor layer on the gate insulation film; and

forming a data line crossing the gate line, a power line crossing the gate line and separated from the data line, a first source electrode, a second source electrode, a first drain electrode, and a second drain electrode on the first substrate with the semiconductor layer,

wherein the gate line and the data line cross each other and define a pixel region,

wherein the first drain electrode is configured to supply the pixel electrode with a level-shifted data voltage, and

wherein the second drain electrode is configured to supply the common electrode with a level-shifted common voltage in a level shifting polarity opposite to the data voltage.

25. The method of claim 24, wherein:

the data line, the power supply line, the pixel electrode, and the common electrode are formed in a structure that is symmetrically bent about a central portion of the pixel region; and

wherein the pixel region has two domains.