OPTICAL LAYERED BODY, POLARIZER AND IMAGE DISPLAY DEVICE

• US 20130194211A1
• Filed: 01/16/2013
• Published: 08/01/2013
• Est. Priority Date: 01/27/2012
• Status: Active Grant

• Current Assignee: Dai Nippon Printing Company Limited
• Original Assignee: Dai Nippon Printing Company Limited
• Inventors: Shinohara, Seiji, Isojima, Seiichi, Nakagawa, Hiroki, Furui, Gen
• Granted Patent: US 8,692,959 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G02B 1/115 Multilayers
• 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 1/133528 Polarisers
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer

Abstract

Provided is an optical layered body that includes a polyester base, a primer layer formed thereon, and a hard coat layer formed on the primer. The polyester has a retardation of not less than 8000 nm, and a difference (nx−ny) of 0.07 to 0.20 between a refractive index (nx) in a slow axis direction that is a high refractive index direction and a refractive index (ny) of a fast axis direction that is orthogonal to the slow axis direction, a refractive index (np) of the primer, the refractive index (nx) in the slow axis direction of the polyester, and the refractive index (ny) in the fast axis direction of the polyester satisfy ny<np<nx, and a refractive index (nh) of the hard coat, the refractive index (nx) in the slow axis direction of the polyester, and the refractive index (ny) in the fast axis direction of the polyester satisfy ny<nh<nx.

Claims

1. An optical layered body comprising:

a polyester base,

a primer layer formed on the polyester base, and

a hard coat layer formed on the primer layer,

wherein

the polyester base has a retardation of not less than 8000 nm, and a difference (nx−

ny) of 0.07 to 0.20 between a refractive index (nx) in a slow axis direction that is a high refractive index direction and a refractive index (ny) of a fast axis direction that is orthogonal to the slow axis direction,

a refractive index (np) of the primer layer, the refractive index (nx) in the slow axis direction of the polyester base, and the refractive index (ny) in the fast axis direction of the polyester base satisfy ny<

np<

nx, and

a refractive index (nh) of the hard coat layer, the refractive index (nx) in the slow axis direction of the polyester base, and the refractive index (ny) in the fast axis direction of the polyester base satisfy ny<

nh<

nx.

6. The optical layered body according to claim 1,

wherein

the primer layer and the hard coat layer are formed on both surfaces of the polyester base.

7. A polarizer comprising a polarizing element,

wherein

the polarizer further includes the optical layered body according to claim 1, on a surface of the polarizing element.

8. An image display device comprising the optical layered body according to claim 1, or the polarizer according to claim 7.

9. A touch panel comprising the optical layered body according to claim 1,

wherein

an invisible electrode is provided on a surface of the hard coat layer of the optical layered body on a side opposite the side covered with the primer layer.

10. A touch panel comprising the optical layered body according to claim 6,

wherein

an invisible electrode is provided on at least one hard coat layer of the optical layered body on a side opposite the side covered with the primer layer.

2. An optical layered body comprising:

a polyester base;

a primer layer formed on the polyester base; and

a hard coat layer formed on the primer layer,

wherein

the polyester base has a retardation of not less than 8000 nm, and a difference (nx−

ny) of 0.07 to 0.20 between a refractive index (nx) in a slow axis direction that is a high refractive index direction and a refractive index (ny) of a fast axis direction that is orthogonal to the slow axis direction,

the primer layer has a thickness of 3 to 30 nm,

a refractive index (nh) of the hard coat layer, the refractive index (nx) in the slow axis direction of the polyester base, and the refractive index (ny) in the fast axis direction of the polyester base satisfy ny<

nh<

nx.

3. The optical layered body according to claim 2,

wherein

the refractive index (ny) in the fast axis direction of the polyester base and a refractive index (np) of the primer layer satisfy ny>

np.

4. The optical layered body according to claim 3,

wherein

a difference (ny−

np) between the refractive index (ny) in the fast axis direction of the polyester base and the refractive index (np) of the primer layer is not more than 0.05.

5. The optical layered body according to claim 2,

wherein a difference (nx−

nh) between the refractive index (nx) in the slow axis direction of the polyester base and the refractive index (nh) of the hard coat layer and a difference (nh−

ny) of the refractive index (nh) of the hard coat layer and the refractive index (ny) in the fast axis direction of the polyester base are both not less than 0.025.

11. The optical layered body according to claim 3, wherein a difference (nx−

nh) between the refractive index (nx) in the slow axis direction of the polyester base and the refractive index (nh) of the hard coat layer and a difference (nh−

ny) of the refractive index (nh) of the hard coat layer and the refractive index (ny) in the fast axis direction of the polyester base are both not less than 0.025.

12. The optical layered body according to claim 4, wherein a difference (nx−

nh) between the refractive index (nx) in the slow axis direction of the polyester base and the refractive index (nh) of the hard coat layer and a difference (nh−

ny) of the refractive index (nh) of the hard coat layer and the refractive index (ny) in the fast axis direction of the polyester base are both not less than 0.025.

13. The optical layered body according to claim 2, wherein the primer layer and the hard coat layer are formed on both surfaces of the polyester base.

14. The optical layered body according to claim 3, wherein the primer layer and the hard coat layer are formed on both surfaces of the polyester base.

15. The optical layered body according to claim 4, wherein the primer layer and the hard coat layer are formed on both surfaces of the polyester base.

16. The optical layered body according to claim 5, wherein the primer layer and the hard coat layer are formed on both surfaces of the polyester base.

17. A polarizer comprising a polarizing element, wherein the polarizer further includes the optical layered body according to claim 2 on a surface of the polarizing element.

18. A polarizer comprising a polarizing element, wherein the polarizer further includes the optical layered body according to claim 3 on a surface of the polarizing element.

19. A polarizer comprising a polarizing element, wherein the polarizer further includes the optical layered body according to claim 4 on a surface of the polarizing element.

20. A polarizer comprising a polarizing element, wherein the polarizer further includes the optical layered body according to claim 5 on a surface of the polarizing element.