# US 2010/0165265 A1 · Liquid crystal display device having wide viewing angle

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- Number: US 2010/0165265 A1
- Document ID: US20100165265A1
- Status: Published application
- Kind: A1
- Application number: 12/649,868
- Filed: 2009-12-30
- Published: 2010-07-01
- Earliest claimed: 2008-12-31
- Assignees: LG Display Co., Ltd.
- Inventors: Jong-Won Moon; Kwang-Hoon Shin
- Web page: https://patentgrep.com/patent/US20100165265A1

## CPC

- 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}
- G02F 1/134363: {for applying an electric field parallel to the substrate, i.e. in-plane switching [IPS]}
- G02F 2202/40: Materials having a particular birefringence, retardation
- G02F 2413/02: Number of plates being 2
- G02F 2413/12: Biaxial compensators
- G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS

## Abstract

Disclosed is a liquid crystal display device having a wide viewing angle, in which compensation films are disposed between a liquid crystal display panel and polarizers to change a polarized state of light, which is incident on the liquid crystal display panel and output therefrom through the polarizers, thereby preventing light from being leaked in a diagonal direction of the liquid crystal display device in a normally black mode.

## Claims

### Claim 1

A liquid crystal display (LCD) device comprising:
a liquid crystal display panel having a liquid crystal layer;
a first polarizer and a second polarizer respectively disposed at upper and lower portions of the liquid crystal display panel to polarize light;
a positive C-film disposed between the first polarizer and the liquid crystal display panel to change a polarized state of light, the positive C-film having a retardation value of Re=0 nm in a horizontal direction and a retardation value of Rth=−50˜−200 nm in a thickness direction; and
a positive biaxial film disposed between the liquid crystal display panel and the second polarizer to change a polarized state of light, the positive biaxial film having a retardation value of Re=80˜160 nm in a horizontal direction and a retardation value of Rth=−24˜−160 nm in a thickness direction,
wherein Re=(nx−ny)d and Rth=(nx−nz)d, where nx, ny and nz respectively denote a refractive index in x-axial direction, a refractive index in y-axial direction and a refractive index in z-axial direction.

### Claim 2 (depends on 1)

The device of claim 1, wherein absorption axes of the first polarizer and the second polarizer are perpendicular to each other.

### Claim 3 (depends on 1)

The device of claim 1, wherein the first polarizer comprises:
a first supporting body; and
a first polarizing body having one surface attached onto the first supporting body.

### Claim 4 (depends on 3)

The device of claim 3, wherein the first supporting body is formed of a transparent protection film.

### Claim 5 (depends on 4)

The device of claim 4, wherein the transparent protection film is formed of triacetylcellulose.

### Claim 6 (depends on 3)

The device of claim 3, wherein the first polarizer is formed of a polyvinyl alcohol (PVA) based resin.

### Claim 7 (depends on 3)

The device of claim 3, wherein the first polarizer comprises:
a first polarizing body; and
a first supporting body disposed between the first polarizer and the positive C-film, the first supporting body being formed of triacetylcellulose without retardation Rth.

### Claim 8 (depends on 1)

The device of claim 1, wherein the second polarizer comprises:
a second supporting body; and
a second polarizing body having one surface attached onto the second supporting body.

### Claim 9 (depends on 8)

The device of claim 8, wherein the second supporting body is formed of a transparent protection film.

### Claim 10 (depends on 9)

The device of claim 9, wherein the transparent protection film is formed of triacetylcellulose.

### Claim 11 (depends on 8)

The device of claim 8, wherein the second polarizer is formed of a polyvinyl alcohol (PVA) based resin.

### Claim 12 (depends on 1)

The device of claim 1, wherein the positive C-film is formed of a UV-curable perpendicularly-aligned liquid crystal film or a biaxially-stretched polymer film.

### Claim 13 (depends on 1)

The device of claim 1, wherein the positive biaxial film is formed of a material selected from a group consisting of UV-curable liquid crystal film polycarbonate, polyethylene terephthalate, polystyrene, uniaxially-stretched TAC, uniaxially-stretched polynorbonene (PNB), biaxially-stretched polycarbonate (PC), biaxially-stretched COP, and biaxial LC film.

### Claim 14 (depends on 1)

The device of claim 1, wherein nx-axis of the positive biaxial film is parallel to a light absorption axis of the second polarizer.

### Claim 15 (depends on 1)

The device of claim 1, wherein the rubbing direction of the liquid crystal display panel is parallel to a light absorption axis of the first polarizer.

### Claim 16 (depends on 1)

The device of claim 1, wherein a non-polarized light is incident through the first polarizer.

### Claim 17 (depends on 1)

The device of claim 1, wherein a non-polarized light is incident through the second polarizer.

### Claim 18 (depends on 1)

The device of claim 1, wherein the liquid crystal display panel is either an in-plane switching (IPS) mode liquid crystal display panel or a fringe field switching (FFS) mode liquid crystal display panel.