Polarizing plate and liquid crystal display comprising the same
A polarizing plate includes: a polarizer; a pattern layer on one surface of the polarizer, the pattern layer including a first refractive index layer having at least one engraved pattern and a second refractive index layer having a filling pattern filling at least a portion of the engraved pattern, the first refractive index layer having a higher refractive index than the second refractive index layer; and a first protective layer. The polarizing plate has a structure in which the polarizer, the second refractive index layer, the first refractive index layer and the first protective layer are sequentially stacked in that order, or in which the polarizer, the first protective layer, the second refractive index layer and the first refractive index layer are sequentially stacked in that order. The first protective layer includes a base film including at least one resin of triacetylcellulose, polyethylene terephthalate, cyclic olefin polymer, and acrylic resins.
1. A polarizing plate comprising:
a polarizer;
a pattern layer arranged at a first side of the polarizer, the pattern layer comprising a first refractive index layer having engraved patterns and each of the engraved patterns having a lenticular or prism shape and a second refractive index layer having a filling pattern filling at least a portion of an engraved pattern of the engraved patterns, a ratio of the sum of maximum pitches of the engraved patterns to a total width of the first refractive index layer being from about 40% to about 60%, and the first refractive index layer having a higher refractive index than the second refractive index layer; and
a first protective layer,
the polarizing plate having a stack structure in which the polarizer, the second refractive index layer, the first refractive index layer and the first protective layer are sequentially stacked in that order, or a stack structure in which the polarizer, the first protective layer, the second refractive index layer and the first refractive index layer are sequentially stacked in that order,
wherein the first protective layer comprises a base film comprising at least one resin of triacetylcellulose, polyethylene terephthalate, cyclic olefin polymer, and acrylic resins, wherein a ratio of a thickness of the pattern layer to a thickness of the first protective layer is 0.1 to about 0.75.
2. The polarizing plate according to claim 1 , wherein the lenticular shape has a curved surface, or the prism shape has a triangular to decagonal cross-section.
3. The polarizing plate according to claim 1 , wherein the prism shape has a truncated triangular cross-sectional prism shape, the lenticular shape has a truncated lenticular lens shape, or the lenticular or prism shape has one or more flat surfaces at an uppermost surface thereof and an n-gonal cross-section, n being an integer greater than or equal to 5.
4. The polarizing plate according to claim 1 , wherein the first refractive index layer further comprises a flat portion between adjacent engraved patterns of the engraved patterns.
5. The polarizing plate according to claim 4 , wherein a ratio of a maximum pitch of an engraved pattern of the adjacent engraved patterns to a pitch of the flat portion is about 1 or less.
6. The polarizing plate according to claim 1 , wherein a difference in refractive index between the first refractive index layer and the second refractive index layer is about 0.30 or less.
7. The polarizing plate according to claim 1 , wherein the first protective layer has an in-plane retardation (Re) of about 8,000 nm or more at a wavelength of 550 nm and comprises a polyethylene terephthalate resin.
8. The polarizing plate according to claim 1 , wherein the first protective layer comprises the base film and a primer layer on at least one surface of the base film, and a ratio of a refractive index of the primer layer to a refractive index of the base film is about 1.0 or less.
9. The polarizing plate according to claim 8 , wherein the first protective layer has a light transmittance of about 90% or more at a wavelength of 550 nm.
10. The polarizing plate according to claim 1 , wherein the base film comprises polyethylene terephthalate resin, and the first protective layer is formed by uniaxially stretching the base film comprising the polyethylene terephthalate resin.
11. The polarizing plate according to claim 1 , wherein the second refractive index layer, the first refractive index layer, and the first protective layer are sequentially stacked on the polarizer.
12. The polarizing plate according to claim 11 , wherein the first refractive index layer is directly on the first protective layer.
13. The polarizing plate according to claim 11 , further comprising a bonding layer between the polarizer and the second refractive index layer.
14. The polarizing plate according to claim 1 , further comprising a second protective layer arranged at a second side of the polarizer that is opposite the first side.
15. The polarizing plate according to claim 14 , wherein the second protective layer comprises a film comprising at least one of triacetylcellulose, polyethylene terephthalate, cyclic olefin polymer, and acrylic resins.
16. A liquid crystal display comprising the polarizing plate according to claim 1 .