IP Library Granted Patent US 7,589,802
Granted Patent B2
US 7,589,802 · App. 11/464,962 · Granted Sep 15, 2009

Liquid crystal display device, method of manufacturing liquid crystal display device and method of designing liquid crystal display device

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Quick Facts
Patent No.
US 7,589,802
App. No.
11/464,962
Granted
Sep 15, 2009
Kind
B2
Abstract

A liquid crystal display device includes an area light source unit which is opposed to one of polarizer. The area light source unit includes a light guide having a light incidence surface opposed to a cold cathode tube, a light emission surface which emits light that is incident on the light incidence surface, and an opposed surface which is opposed to the light emission surface, and a prismatic sheet disposed between the polarizer plate and the light guide. The light guide has prisms on at least the opposed surface. The prismatic sheet has prisms which extend in a direction that is displaced counterclockwise by a first predetermined angle from a direction that is perpendicular to a direction of extension of the prisms. An angle between a polarization axis of the polarizer plate and a polarization axis of the prismatic sheet is set at a second predetermined angle.

Claims (25)

1. A liquid crystal display device comprising:

a liquid crystal display panel in which a liquid crystal layer is held between a pair of mutually opposed substrates;

polarizer plates which are disposed on outer surfaces of the pair of substrates; and

an area light source unit which is opposed to one of the polarizer plates,

wherein the area light source unit includes:

a light source;

a light guide having a light incidence surface which is opposed to the light source, a light emission surface which emits light that is incident on the light incidence surface, and an opposed surface which is opposed to the light emission surface; and

a prismatic sheet which is disposed between said one of the polarizer plates and the light guide,

the light guide has prisms on at least one of the light emission surface and the opposed surface,

the prismatic sheet has prisms which extend in a direction that is displaced counterclockwise by a first predetermined angle from a direction that is perpendicular to a direction of extension of the prisms of the light guide, and

an angle between a polarization axis of said one of the polarizer plates and a polarization axis of the prismatic sheet is set between 0° and 20°.

2. The liquid crystal display device according to claim I, wherein the first predetermined angle is set between 4° and 8°.

3. The liquid crystal display device according to claim 1 , wherein the prismatic sheet is formed of a PET base material.

4. A liquid crystal display device comprising:

a liquid crystal display panel in which a liquid crystal layer is held between a pair of mutually opposed substrates;

polarizer plates which are disposed on outer surfaces of the pair of substrates; and

an area light source unit which is opposed to one of the polarizer plates,

wherein the area light source unit includes:

a light source;

a light guide having a light incidence surface which is opposed to the light source, a light emission surface which emits light that is incident on the light incidence surface, and an opposed surface which is opposed to the light emission surface; and

a prismatic sheet which is disposed between said one of the polarizer plates and the light guide,

the light guide has prisms on at least one of the light emission surface and the opposed surface,

the prismatic sheet has prisms which extend in a direction that is displaced counterclockwise by a first predetermined angle between 4° and 8° from a direction that is perpendicular to a direction of extension of the prisms of the light guide, and

an angle between a polarization axis of said one of the polarizer plates and a polarization axis of the prismatic sheet is set at a second predetermined angle.

5. The liquid crystal display device according to claim 4 , wherein the prismatic sheet is formed of a PET base material.

Assignments (4)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 24, 2025
From: JAPAN DISPLAY INC.
To: MAGNOLIA WHITE CORPORATION
Reel/Frame 072209/0001 →
MERGER AND CHANGE OF NAME Recorded Jul 2, 2025
From: JAPAN DISPLAY EAST INC.; JAPAN DISPLAY CENTRAL INC.
To: JAPAN DISPLAY INC.
Reel/Frame 071787/0434 →
CHANGE OF NAME Recorded Jun 8, 2012
From: TOSHIBA MATSUSHITA DISPLAY TECHNOLOGY CO., LTD.
To: TOSHIBA MOBILE DISPLAY CO., LTD.
Reel/Frame 028339/0273 →
CHANGE OF NAME Recorded Jun 8, 2012
From: TOSHIBA MOBILE DISPLAY CO., LTD.
To: JAPAN DISPLAY CENTRAL INC.
Reel/Frame 028339/0316 →