LIQUID CRYSTAL PANEL AND LIQUID CRYSTAL DISPLAY APPARATUS

• US 20100182546A1
• Filed: 03/26/2007
• Published: 07/22/2010
• Est. Priority Date: 04/05/2006
• Status: Active Grant

• Current Assignee: Nitto Denko Corporation
• Original Assignee: Nitto Denko Corporation
• Inventors: Niinou, Teppei, Maezawa, Shouhei, Nagano, Shinobu, Osuka, Tatsuya
• Granted Patent: US 8,031,296 B2
• Time in Patent Office: Days
• US Class Current: 349/96
• CPC Class Codes: G02B 5/30 Polarising elements light-modulating devices with active elements G02F1/00
• CPC Class Codes: G02F 1/133528 Polarisers

Abstract

It is an object of the present invention to provide a liquid crystal display panel having a high contrast ratio.

A liquid crystal panel according to an embodiment of the present invention includes: a liquid crystal cell; a first polarizing plate placed on a viewer side of the liquid crystal cell; and a second polarizing plate placed on an opposite side of the liquid crystal cell with respect to the viewer side. A light transmittance (T₂) of the second polarizing plate is larger than a light transmittance (T₁) of the first polarizing plate. Such a liquid crystal panel has a remarkably high contrast ratio and shows excellent display properties, compared to conventional liquid crystal panel.

Claims

1. A liquid crystal panel, comprising:

a liquid crystal cell;

a first polarizing plate placed on a viewer side of the liquid crystal cell; and

a second polarizing plate placed on an opposite side of the liquid crystal cell with respect to the viewer side,

wherein a light transmittance (T₂) of the second polarizing plate is larger than a light transmittance (T₁) of the first polarizing plate.

2. A liquid crystal panel according to claim 1, wherein a difference (Δ

T=T₂−

T₁) between the light transmittance (T₂) of the second polarizing plate and the light transmittance (T₁) of the first polarizing plate is 0.1% to 6.0%.

3. A liquid crystal panel according to claim 1, wherein the liquid crystal cell includes a liquid crystal layer containing liquid crystal molecules arranged in a homogeneous alignment in the absence of an electric field.

4. A liquid crystal panel according to claim 1, wherein the light transmittance (T₁) of the first polarizing plate is 38.3% to 43.3%.

5. A liquid crystal panel according to claim 1, wherein the light transmittance (T₂) of the second polarizing plate is 41.1% to 44.3%.

6. A liquid crystal panel according to claim 1, wherein a degree of polarization of the first polarizing plate and/or the second polarizing plate is 99% or more.

7. A liquid crystal panel according to claim 1, wherein the first polarizing plate includes a first polarizer, the second polarizing plate includes a second polarizer, and the first polarizer and the second polarizer respectively contain as a main component an iodine-containing polyvinyl alcohol-based resin.

8. A liquid crystal panel according to claim 7, wherein a difference (Δ

T=I₁−

I₂) between an iodine content (I₁) of the first polarizer and an iodine content (I₂) of the second polarizer is 0.1% by weight to 1.9% by weight.

9. A liquid crystal panel according to claim 7, wherein the iodine content of the first polarizer and/or the second polarizer is 2.0% by weight to 5.0% by weight.

10. A liquid crystal panel according to claim 7, wherein the first polarizer and/or the second polarizer further contain potassium, and a content of the potassium is 0.2% by weight to 1.0% by weight.

11. A liquid crystal panel according to claim 1, further comprising a brightness enhancing film on an opposite side of the second polarizing plate with respect to the liquid crystal cell side.

12. A liquid crystal panel according to claim 11, wherein the brightness enhancing film is a laminate including a thermoplastic resin layer (A) and a thermoplastic resin layer (B), and an in-plane birefringence of the thermoplastic resin layer (A) is 0.05 or more.

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