Polarizing plate for OLED and OLED display including the same

1. A polarizing plate for an OLED, the polarizing plate comprising:

a polarizer;

a first retardation layer on a lower side of the polarizer;

a second retardation layer on a lower side of the first retardation layer; and

a pattern layer on a lower side of the second retardation layer, the pattern layer including a plurality of engraved patterns on a lower side thereof.

2. The polarizing plate as claimed in claim 1 , wherein the pattern layer has an index of refraction of about 1.46 to about 1.80.

3. The polarizing plate as claimed in claim 1 , wherein an aspect ratio (H/A) of a height (H) of each engraved pattern to a width (A) of each engraved pattern is about 1 to about 3.

4. The polarizing plate as claimed in claim 1 , wherein:

the engraved patterns are separated from each other, and

a ratio (S/A) of a separation (S) between the engraved patterns to a width (A) of each of the engraved patterns is about 3.0 or less.

5. The polarizing plate as claimed in claim 1 , wherein the pattern layer includes at least one of a (meth)acrylic resin, a polycarbonate resin, a polyester resin, a cycloolefin polymer resin, a cellulose resin, or a polyvinyl chloride resin.

6. The polarizing plate as claimed in claim 1 , wherein each of the engraved patterns includes a filling section that is filled with a filler, the filler having a lower index of refraction than that of the pattern layer.

7. The polarizing plate as claimed in claim 6 , wherein the filler includes air.

8. The polarizing plate as claimed in claim 6 , wherein the filler includes a filling resin having an index of refraction of about 1.20 to about 1.45.

9. The polarizing plate as claimed in claim 6 , wherein the filler includes:

a filling resin layer having an index of refraction of about 1.20 to about 1.45, and

an air layer stacked on the filling resin layer in a thickness direction of the filling section.

10. The polarizing plate as claimed in claim 6 , wherein the filler includes:

a filling resin layer having an index of refraction from about 1.20 to about 1.45, and

an adhesive layer stacked on the filling resin layer in a thickness direction of the filling section.

11. The polarizing plate as claimed in claim 6 , wherein the filler includes:

a filling resin having an index of refraction of about 1.20 to about 1.45, and

a light spreading agent.

12. The polarizing plate as claimed in claim 1 , further comprising at least one of an adhesive layer, a first optical layer, a second optical layer, and a light spreading layer on a lower side of the pattern layer, wherein:

when the first optical layer is included, the first optical layer has a lower index of refraction than the pattern layer,

when the first optical layer and the second optical layer are included, the second optical layer has a lower index of refraction than the first optical layer.

13. The polarizing plate as claimed in claim 1 , further comprising a base layer between the second retardation layer and the pattern layer.

14. The polarizing plate as claimed in claim 13 , further comprising a light spreading layer between the base layer and the pattern layer.

15. The polarizing plate as claimed in claim 1 , further comprising a protective layer on an upper side of the polarizer.

16. The polarizing plate as claimed in claim 8 , wherein the filling resin includes at least one of a (meth)acrylic resin, a polycarbonate resin, a polyester resin, a cycloolefin polymer resin, a cellulose resin, or a polyvinyl chloride resin.

17. The polarizing plate as claimed in claim 12 , wherein:

the polarizing plate includes the first optical layer, and

the first optical layer includes at least one of a (meth)acrylic resin, a polycarbonate resin, a polyester resin, a cycloolefin polymer resin, a cellulose resin, or a polyvinyl chloride resin.

18. The polarizing plate as claimed in claim 1 , wherein:

the first retardation layer has an in-plane retardation (Re) at a wavelength of 550 nm of about 250 nm to about 300 nm, and

the second retardation layer has an in-plane retardation (Re) at a wavelength of 550 nm of about 110 nm to about 160 nm.

19. The polarizing plate as claimed in claim 1 , wherein:

the first retardation layer has an out-of-plane retardation (Rth) at a wavelength of 550 nm of about 0 nm to about 300 nm, and

the second retardation layer has an out-of-plane retardation (Rth) at a wavelength of 550 nm of about −160 nm to about 0 nm.

20. The polarizing plate as claimed in claim 1 , wherein:

the first retardation layer has a short wavelength dispersibility of about 1.00 to about 1.05 and a long wavelength dispersibility of about 0.95 to about 1.00, and

the second retardation layer has a short wavelength dispersibility of about 1.00 to about 1.20 and a long wavelength dispersibility of about 0.85 to about 1.00.

21. The polarizing plate as claimed in claim 1 , wherein:

an angle defined between a slow axis of the first retardation layer and an absorption axis of the polarizer is about 63° to about 73° or about −73° to about −63°, and

an angle defined between a slow axis of the second retardation layer and the absorption axis of the polarizer is about −5° to about 5°.

22. An OLED display comprising the polarizing plate for an OLED as claimed in claim 1 .