NANOCAPSULE LIQUID CRYSTAL DISPLAY DEVICE

• US 20160011443A1
• Filed: 06/26/2015
• Published: 01/14/2016
• Est. Priority Date: 07/09/2014
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: JEON, Ji-Na, KIM, Kyeong-Jin, CHOI, Min-Geon
• Granted Patent: US 10,061,149 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G02F 1/1334 based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals
• CPC Class Codes: G02F 1/133634 the refractive index Nz perpendicular to the element surface being different from in-plane refractive indices Nx and Ny, e.g. biaxial or with normal optical axis
• 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 2202/36 Micro- or nanomaterials

Abstract

Disclosed is a nanocapsule liquid crystal display device. The display includes a liquid crystal panel having a substrate and a nanocapsule liquid crystal layer over the substrate; a first polarizing plate on an outer surface of the substrate and including a first polarizing layer; and a second polarizing plate directly on an outer surface of the nanocapsule liquid crystal layer and including a second polarizing layer and a phase difference layer, wherein a retardation of the nanocapsule liquid crystal layer is compensated by the phase difference layer.

Claims

1. A nanocapsule liquid crystal display device, comprising:

a liquid crystal panel including a substrate and a nanocapsule liquid crystal layer over the substrate;

a first polarizing plate on an outer surface of the substrate and including a first polarizing layer; and

a second polarizing plate directly on an outer surface of the nanocapsule liquid crystal layer and including a second polarizing layer and a phase difference layer,

wherein a retardation of the nanocapsule liquid crystal layer is compensated by the phase difference layer.

2. The device of claim 1, wherein a summation of thickness retardation values of the nanocapsule layer and the phase difference layer is zero.

3. The device of claim 2, wherein the nanocapsule liquid crystal layer has thickness of about 1 to about 10 micrometers and a negative C property, and a thickness retardation value of the nanocapsule layer is within about −

40 to about −

5 nm.

4. The device of claim 3, wherein the phase difference layer has a positive C property.

5. The device of claim 4, wherein the first polarizing plate further includes a base film disposed between the first polarizing layer and the substrate and being a zero retardation film, and wherein a thickness retardation value of the phase difference layer is within about 5 to about 40 nm.

6. The device of claim 4, wherein the first polarizing plate further includes a base film disposed between the first polarizing layer and the substrate and being a non-zero retardation film with a thickness retardation value within about −

75 to about −

80 nm, and wherein a thickness retardation value of the phase difference layer is within about 80 to about 120 nm.

7. The device of claim 3, wherein the phase difference layer has a positive biaxial property.

8. The device of claim 7, wherein the first polarizing plate further includes a base film disposed between the first polarizing layer and the substrate and being a zero retardation film, and wherein the phase difference layer has an in-plane retardation value within about 5 to about 40 nm and a thickness retardation value within about 5 to about 40 nm.

9. The device of claim 7, wherein the first polarizing plate further includes a base film disposed between the first polarizing layer and the substrate and being a non-zero retardation film with a thickness retardation value within about −

75 to about −

80 nm, and wherein the phase difference layer has an in-plane retardation value within about 80 to about 120 nm and a thickness retardation value within about 80 to about 120 nm.

10. The device of claim 1, wherein a transmissive axis of the first polarizing plate is perpendicular to a transmissive axis of the second polarizing plate.

11. The device of claim 1, wherein the first polarizing plate further includes a first base film under the first polarizing layer, a second base film between the first polarizing layer and the substrate and an adhesive layer between the second base film and the substrate.

12. The device of claim 1, wherein the second polarizing plate further includes an adhesive layer between the phase difference layer and the nanocapsule liquid crystal layer, and the second polarizing plate is directly attached on the nanocapsule liquid crystal layer by the adhesive layer.

13. The device of claim 1, wherein the nanocapsule liquid crystal layer includes a plurality of nano-sized capsules, each of which includes a plurality of liquid crystal molecules therein, dispersed in a buffer layer.

14. The device of claim 13, wherein a diameter of each nano-sized capsule is about 1 nm to about 320 nm.

15. The device of claim 13, wherein a volume of the nano-sized capsule is about 25% to about 65% of a volume of the nanocapsule liquid crystal layer.

16. The device of claim 13, wherein a refractive index difference between the nematic liquid crystal molecule and the nano-sized capsule is about ±

0.1.

17. The device of claim 1, wherein the nanocapsule liquid crystal layer is formed by a curing process such that a vertical diameter of the nanocapsule is smaller than a horizontal diameter of the nanocapsule.

18. The device of claim 1, wherein the liquid crystal panel further includes:

gate and data lines on the substrate and crossing each other to define a pixel region;

a thin film transistor in the pixel region and connected to the gate and data lines;

a pixel electrode in the pixel region and connected to the thin film transistor; and

a common electrode in the pixel region and spaced apart from the pixel electrode.

19. The device of claim 18, wherein the nanocapsule liquid crystal layer contacts the pixel and common electrodes.

20. The device of claim 1, further comprising:

a backlight unit located below the first polarizing plate and including a light source.