# US 2014/0192297 A1 · Liquid crystal display device with wide-viewing angle

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- Number: US 2014/0192297 A1
- Document ID: US20140192297A1
- Status: Published application
- Kind: A1
- Application number: 14/144,142
- Filed: 2013-12-30
- Published: 2014-07-10
- Earliest claimed: 2013-01-04
- Assignees: LG Display Co., Ltd.
- Applicants: LG Display Co., Ltd.
- Inventors: Sang-Woong CHOI; Jeong-Hoon KO; Hyoun-Sung SON; Eun-Jung KIM; Dong-Ha YOO
- Web page: https://patentgrep.com/patent/US20140192297A1

## CPC

- G02F 1/13363: Birefringent elements, e.g. for optical compensation
- 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 1/133638: {Waveplates, i.e. plates with a retardation value of lambda/n}
- G02F 2413/02: Number of plates being 2
- G02F 2413/04: Number of plates greater than or equal to 4
- G02F 2413/05: Single plate on one side of the LC cell
- G02F 2413/06: Two plates on one side of the LC cell
- 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

An LCD device includes a liquid crystal panel; a first polarizer attached to a first surface of the liquid crystal panel and including a first polarizing film, first and second optical compensation films disposed on one surface of the first polarizing film, and a phase retardation film, a protective film and a functional film disposed on another surface of the first polarizing film; and a second polarizer attached to a second surface of the liquid crystal panel and including a second polarizing film, an inner protective film disposed on one surface of the second polarizing film, and an outer protective film disposed on another surface of the second polarizing film, wherein the first polarizing film is disposed between the phase retardation film and the liquid crystal panel, and the phase retardation film has a retardation value of λ/4.

## Claims

### Claim 1

A liquid crystal display device, comprising:
a liquid crystal panel;
a first polarizer attached to a first surface of the liquid crystal panel and including a first polarizing film, first and second optical compensation films, a phase retardation film, a protective film, and a functional film, wherein the first and second optical compensation films are disposed on one surface of the first polarizing film, and the phase retardation film, the protective film and the functional film are disposed on another surface of the first polarizing film; and
a second polarizer attached to a second surface of the liquid crystal panel and including a second polarizing film, an inner protective film, and an outer protective film, wherein the inner protective film is disposed on one surface of the second polarizing film, and the outer protective film is disposed on another surface of the second polarizing film,
wherein the first polarizing film is disposed between the phase retardation film and the liquid crystal panel, and the phase retardation film has a retardation value of λ/4.

### Claim 2 (depends on 1)

The device according to claim 1, wherein the first optical compensation film is a negative B plate, and the second optical compensation film is a positive C plate.

### Claim 3 (depends on 2)

The device according to claim 2, wherein the second optical compensation film is disposed between the first optical compensation film and the liquid crystal panel.

### Claim 4 (depends on 2)

The device according to claim 2, where the first optical compensation film has an in-plane retardation value of 120±10 nm and a thickness retardation value of 100±30 nm, and the second optical compensation film has a thickness retardation value of −130±30 nm.

### Claim 5 (depends on 1)

The device according to claim 1, wherein the phase retardation film includes a liquid crystal material, and an alignment layer is formed between the protective film and the phase retardation film.

### Claim 6 (depends on 1)

The device according to claim 1, wherein the second optical compensation film includes a liquid crystal material, and an alignment layer is formed between the first optical compensation film and the second optical compensation film.

### Claim 7 (depends on 1)

The device according to claim 1, wherein the functional film includes an anti-static layer and a hard-coating layer.

### Claim 8 (depends on 7)

The device according to claim 7, wherein the anti-static layer includes gold and azo tin oxide.

### Claim 9 (depends on 1)

The device according to claim 1, wherein the second polarizer further includes a brightness enhancement film on an outer surface of the outer protective film.