Optical film, optical compensation film, polarizing plate and liquid crystal display

Patent metadata

Field	Value
Publication number	US-9348177-B2
Application number	US-201514792835-A
Country	US
Kind code	B2
Filing date	Jul 7, 2015
Priority date	Sep 9, 2005
Publication date	May 24, 2016
Grant date	May 24, 2016

Abstract

An optical film is provided and has retardations satisfying relations (1) to (3):

0≦ Re (550)≦10;  (1)

−25≦ Rth (550)≦25; and  (2)

| I|+|II|+|III|+|IV |>0.5 (nm),  (3)

with definitions:
I=Re(450)−Re(550); II=Re(650)−Re(550); III=Rth(450)−Rth(550); and IV=Rth(650)−Rth(550),

wherein Re(450), Re(550) and Re(650) are in-plane retardations measured with lights of wavelength of 450, 550 and 650 nm, respectively; and Rth(450), Rth(550) and Rth(650) are retardations in a thickness direction of the optical film, which are measured with lights of wavelength of 450, 550 and 650 nm, respectively.

First claim

What is claimed is:

1. An optical film having retardations satisfying relations (1) to (3):
1≦ Re (550)≦5;  (1)

−15≦ Rth (550)≦15; and  (2)

| I|+|II|+|III|+|IV|> 0.5 (nm),  (3)

with definitions:
I=Re(450)−Re(550);
II=Re(650)−Re(550);
III=Rth(450)−Rth(550); and
IV=Rth(650)−Rth(550),
wherein Re(450), Re(550) and Re(650) are in-plane retardations of 450, 550 and 650 nm, respectively; and Rth(450), Rth(550) and Rth(650) are retardations in a thickness direction of the optical film, which are of wavelength of 450, 550 and 650 nm, respectively, and
wherein I, II, III and IV satisfy relations (4-D) to (7-D):
0< I≦ 50;  (4-D)

−50≦ II< 0;  (5-D)

−50≦ III≦ 0; and  (6-D)

0 ≦IV≦ 50,  (7-D)

wherein a material for forming the optical film comprises an acrylic polymer, or cellulose acylate.

2. The optical film according to claim 1 , wherein −15≦Rth(550)≦0.

3. The optical film according to claim 1 , wherein the optical film is stretched.

4. The optical film according to claim 1 , wherein the optical film has a thickness of from 20 to 200 μm.

5. The optical film according to claim 1 , wherein the material for forming the optical film is cellulose acylate.

6. The optical film according to claim 5 , wherein the cellulose acylate has an acyl substituent, the acyl substituent is substantially only an acetyl group, and a total substitution degree of the acyl substituent is from 2.56 to 3.00.

7. A polarizing plate comprising: a polarizer; and the optical film according to claim 1 .

8. A liquid crystal display comprising:
a substrate;
the optical film according to claim 1 ; and
a liquid crystal cell containing liquid crystal molecules aligned to be substantially parallel to the substrate in a black display state of the liquid crystal display,
wherein the optical film is disposed directly on the liquid crystal cell.

9. The optical film according to claim 1 , wherein:
−11.2≦ III≦− 0.1; and  (6-D)

0≦ IV≦ 4.8.  (7-D)

10. The optical film according to claim 1 , wherein: |I|+|II|+|III|+|IV|>4.0 (nm).

11. The optical film according to claim 1 , wherein −2.0≦Rth(550)≦15 nm.

Assignees

• Fujifilm Corp

Inventors

• Nakayama Hajime
• Toyama Hirofumi
• Takahashi Yuta

Classifications

• G02F2001/133531

  Physics · mapped topic

• G02F2001/133638

  Physics · mapped topic

• G02B5/3083

  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 title

• G02F2413/02

  Number of plates being 2 · CPC title

• G02F2202/40

  Materials having a particular birefringence, retardation · CPC title