LIQUID CRYSTAL PANEL, LIQUID CRYSTAL DISPLAY APPARATUS USING THE PANEL, AND METHOD OF PRODUCING A LIQUID CRYSTAL PANEL

• US 20100134737A1
• Filed: 01/26/2007
• Published: 06/03/2010
• Est. Priority Date: 02/20/2006
• Status: Abandoned Application

• Current Assignee: Nitto Denko Corporation
• Original Assignee: Nitto Denko Corporation
• Inventors: Hada, Kazuya, Kamijou, Takashi, Umemoto, Seiji, Yonezawa, Hideyuki, Kawamoto, Ikuo, Kobayashi, Kentarou
• Application Number:
  US12/067,467
• Publication Number:
  US 20100134737A1
• Time in Patent Office: Days
• US Class Current: 349/119
• CPC Class Codes: G02B 5/3083 Birefringent or phase retarding elements G02B5/3008, G02B5/3016 take precedence; systems for polarisation control G02B27/286; manufacturing phase modulating patterns by lithographic processes G03F7/001
• CPC Class Codes: G02F 1/133555 Transflectors
• CPC Class Codes: G02F 1/13363 Birefringent elements, e.g. for optical compensation
• CPC Class Codes: G02F 1/133633 using mesogenic materials
• 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 1/133635 Multifunctional compensators
• 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 2201/50 Protective arrangements
• CPC Class Codes: G02F 2202/28 Adhesive materials or arrangements
• CPC Class Codes: G02F 2413/04 Number of plates greater than or equal to 4
• CPC Class Codes: G02F 2413/13 Positive birefingence

Abstract

Provided are a liquid crystal panel and a liquid crystal display apparatus each of which: contributes to a reduction in thickness; and is excellent in optical characteristics, and a method of producing the liquid crystal panel with extremely high production efficiency. A liquid crystal panel of the present invention has a first polarizer, a first protective layer, a first optical compensation layer, a first negative C plate, a liquid crystal cell, a second negative C plate, a second optical compensation layer, a second protective layer, and a second polarizer in the stated order. The first optical compensation layer is arranged between the first protective layer and the first negative C plate to be in close contact with the first protective layer without using any adhesive. The second optical compensation layer is arranged between the second negative C plate and the second protective layer to be in close contact with the second protective layer without using any adhesive. The first and second optical compensation layers are each a coating layer functioning as a λ/4 plate, and each have a thickness of 0.3 to 3 μm. The first and second negative C plates are each a coating layer, and each have a thickness of 0.5 to 10 μm.

Claims

1. A liquid crystal panel, comprising:

a liquid crystal cell;

a first polarizer arranged on one side of the liquid crystal cell;

a second polarizer arranged on the other side of the liquid crystal cell;

a first protective layer, a first optical compensation layer, and a first negative C plate arranged between the first polarizer and the liquid crystal cell; and

a second negative C plate, a second optical compensation layer, and a second protective layer arranged between the liquid crystal cell and the second polarizer, wherein;

the first optical compensation layer is arranged between the first protective layer and the first negative C plate to be in close contact with the first protective layer without using any adhesive;

the second optical compensation layer is arranged between the second negative C plate and the second protective layer to be in close contact with the second protective layer without using any adhesive;

the first optical compensation layer and the second optical compensation layer each comprise a coating layer functioning as a λ

/4 plate, and each have a thickness of 0.3 to 3 μ

m; and

the first negative C plate and the second negative C plate each comprise a coating layer, and each have a thickness of 0.5 to 10 μ

m.

2. A liquid crystal display apparatus, comprising the liquid crystal panel according to claim 1.

3. A method of producing a liquid crystal panel, comprising the steps of:

subjecting a surface of a first protective layer to an alignment treatment;

forming a first optical compensation layer on the surface of the first protective layer that has been subjected to the alignment treatment;

laminating a first polarizer on a remaining surface of the first protective layer;

sticking a first negative C plate to a surface of the first optical compensation layer opposite to the first protective layer to provide a first laminate;

sticking a side of the first negative C plate of the first laminate to one surface of a liquid crystal cell;

subjecting a surface of a second protective layer to the alignment treatment;

forming a second optical compensation layer on the surface of the second protective layer that has been subjected to the alignment treatment;

laminating a second polarizer on a remaining surface of the second protective layer;

sticking a second negative C plate to a surface of the second optical compensation layer opposite to the second protective layer to provide a second laminate; and

sticking a side of the second negative C plate of the second laminate to the other surface of the liquid crystal cell.

4. A production method according to claim 3, wherein the step of forming the first optical compensation layer includes the steps of:

applying a liquid crystal material onto the first protective layer; and

treating the applied liquid crystal material at a temperature at which the liquid crystal material shows a liquid crystal phase.

5. A production method according to claim 3, wherein:

the first negative C plate is formed by a method including the steps of;

applying a liquid crystal composition containing a liquid crystal material and a chiral agent onto a substrate; and

treating the applied liquid crystal composition at a temperature at which the liquid crystal material shows a liquid crystal phase; and

the production method further comprises the step of peeling the substrate after the sticking of the first negative C plate to the surface of the first optical compensation layer opposite to the first protective layer.

6. A production method according to claim 3, wherein the step of forming the second optical compensation layer includes the steps of:

applying a liquid crystal material onto the second protective layer; and

treating the applied liquid crystal material at a temperature at which the liquid crystal material shows a liquid crystal phase.

7. A production method according to claim 3, wherein:

the second negative C plate is formed by a method including the steps of;

applying a liquid crystal composition containing a liquid crystal material and a chiral agent onto a substrate; and

treating the applied liquid crystal composition at a temperature at which the liquid crystal material shows a liquid crystal phase; and

the production method further comprises the step of peeling the substrate after the sticking of the second negative C plate to the surface of the second optical compensation layer opposite to the second protective layer.

8. A production method according to claim 3, wherein:

the first negative C plate is formed by a method including the step of applying a solution containing at least one kind of a non-liquid crystalline polymer selected from the group consisting of polyamide, polyimide, polyester, polyetherketone, polyamideimide, and polyesterimide onto a substrate; and

the production method further comprises the step of peeling the substrate after the sticking of the first negative C plate to the surface of the first optical compensation layer opposite to the first protective layer.

9. A production method according to claim 3, wherein:

the second negative C plate is formed by a method including the step of applying a solution containing at least one kind of a non-liquid crystalline polymer selected from the group consisting of polyamide, polyimide, polyester, polyetherketone, polyamideimide, and polyesterimide onto a substrate; and

the production method further comprises the step of peeling the substrate after the sticking of the second negative C plate to the surface of the second optical compensation layer opposite to the second protective layer.