OPTICAL FILM, POLARIZING PLATE, AND IMAGE DISPLAY APPARATUS

• US 20090091835A1
• Filed: 09/26/2008
• Published: 04/09/2009
• Est. Priority Date: 09/28/2007
• Status: Active Grant

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Inventors: Suzuki, Takato, WAKIZAKA, Daiki
• Granted Patent: US 8,322,869 B2
• Time in Patent Office: Days
• US Class Current: 359/586
• CPC Class Codes: G02B 1/115 Multilayers
• CPC Class Codes: G02B 5/3033 in the form of a thin sheet or foil, e.g. Polaroid
• CPC Class Codes: Y10T 428/26 Web or sheet containing structurally defined element or component, the element or component having a specified physical dimension

Abstract

An optical film includes, in the following order, a support; an antiglare layer having an uneven surface; a high refractive index layer; and a low refractive index layer, wherein an arithmetic average roughness (Ra) of the optical film is: 0.03 μm<Ra<0.4 μm, an average distance of unevenness (Sm) of the optical film is: 80 μm<Sm<700 μm, a region of 0°<θ<0.5° (θ (0.5)) of the optical film, where θ is a tilting angle of the unevenness, accounts for 40% or more, and an integral reflectance of the optical film is 1.5% or less.

Claims

1. An optical film comprising, in the following order:

a support;

an antiglare layer having an uneven surface;

a high refractive index layer; and

a low refractive index layer,

wherein

an arithmetic average roughness (Ra) of the optical film is;

0.03 μ

m<

Ra<

0.4 μ

m,

an average distance of unevenness (Sm) of the optical film is;

80 μ

m<

Sm<

700 μ

m,

a region of 0°

<

θ

<

0.5°

(θ

(0.5)) of the optical film, where θ

is a tilting angle of unevenness, accounts for 40% or more, and

an integral reflectance of the optical film is 1.5% or less.

2. The optical film of claim 1, wherein

the antiglare layer contains at least one kind of light transmissive particles having an average particle diameter larger than an average film thickness of the antiglare layer by 0.01 to 4.0 μ

m.

3. The optical film of claim 2, wherein

an amount of the light transmissive particles to be added is 0.01 to 1 mass % based on a total solid content of the antiglare layer.

4. The optical film of claim 2, wherein

the number per unit area in the antiglare layer of the light transmissive particles having a larger average particle diameter than the average film thickness of the antiglare layer is 10 to 1500 particles/mm².

5. The optical film of claim 2, wherein

the antiglare layer contains second light transmissive particles having a smaller average particle diameter than the average film thickness of the antiglare layer.

6. The optical film of claim 1, wherein

the antiglare layer contains at least one kind of fine particles, and

the fine particles are cohesive metal oxide fine particles.

7. The optical film of claim 6, wherein

an amount of the metal oxide fine particles to be added is 0.01 to 5 mass % based on a total solid content of the antiglare layer.

8. The optical film of claim 6, wherein

the antiglare layer contains second light transmissive particles having a smaller average particle diameter than an average film thickness of the antiglare layer.

9. The optical film of claim 1, wherein

the high refractive index layer contains fine particles of an oxide of at least one metal selected from Si, Al, Ti, Zr, Sb, Zn, Sn, and In.

10. The optical film of claim 9, wherein

the fine particles of the oxide of at least one metal are contained in an amount of 30 mass % or more based on a total solid content of the high refractive index layer.

11. The optical film of claim 1, wherein

the high refractive index layer comprises a fluorine type or silicone type levelling agent.

12. The optical film of claim 1, further comprising:

an intermediate refractive index layer having a refractive index higher than that of the antiglare layer and lower than that of the high refractive index layer, provided between the antiglare layer and the high refractive index layer.

13. The optical film of claim 12, wherein

the intermediate refractive index layer contains fine particles of an oxide of at least one metal selected from Si, Al, Ti, Zr, Sb, Zn, Sn, and In.

14. The optical film of claim 13, wherein

the fine particles of the oxide of at least one metal are contained in an amount of 30 mass % or more based on a total solid content of the intermediate refractive index layer.

15. The optical film of claim 12, wherein

the intermediate refractive index layer comprises a fluorine type or silicone type levelling agent.

16. A polarizing plate comprising:

a polarizing film; and

a pair of protective films provided on the both sides of the polarizing film,

wherein

at least one of the pair of the protective films is the optical film of claim 1.

17. An image display apparatus comprising:

the optical film of claim 1 on an outermost surface of the display.

18. An image display apparatus comprising:

the polarizing plate of claim 16 on an outermost surface of the display.