POLARIZING PLATE AND OPTICAL DISPLAY APPARATUS
Disclosed are a polarizing plate and an optical display apparatus including the same. The polarizing plate includes: a polarizer; and a retardation layer formed on one surface of the polarizer, wherein the retardation layer comprises a liquid crystal retardation layer, the liquid crystal retardation layer satisfying Formula 1 described in detail in the specification.
1 . A polarizing plate comprising:
a polarizer; and
a retardation layer on one surface of the polarizer,
wherein the retardation layer comprises a liquid crystal retardation layer, the liquid crystal retardation layer satisfying Formula 1:
5
≤
❘
"\[LeftBracketingBar]"
(
CD
(
400
nm
)
-
CD
(
300
nm
)
)
/
100
❘
"\[RightBracketingBar]"
≤
23
,
(
1
)
where CD(400) is a circular dichroism value, in unit of mdeg, of the liquid crystal retardation layer at a wavelength of 400 nm, and
CD(300) is a circular dichroism value, in unit of mdeg, of the liquid crystal retardation layer at a wavelength of 300 nm.
2 . The polarizing plate as claimed in claim 1 , wherein the liquid crystal retardation layer has a CD(300) value of −2,500 mdeg to −500 mdeg and a CD(400) value of −500 mdeg to 0 mdeg.
3 . The polarizing plate as claimed in claim 1 , wherein the liquid crystal retardation layer has an in-plane retardation of 100 nm to 155 nm at a wavelength of 550 nm.
4 . The polarizing plate as claimed in claim 1 , wherein the liquid crystal retardation layer comprises a twisted nematic liquid crystal layer.
5 . The polarizing plate as claimed in claim 1 , wherein the liquid crystal retardation layer has a thickness of 10 μm or less.
6 . The polarizing plate as claimed in claim 1 , wherein the liquid crystal retardation layer has a thickness of greater than 1.0 μm and less than or equal to 3.5 μm.
7 . The polarizing plate as claimed in claim 1 , wherein the liquid crystal retardation layer comprises a dry or cured product of a composition comprising a twisted nematic liquid crystal compound and a chiral agent.
8 . The polarizing plate as claimed in claim 7 , wherein the chiral agent comprises an acrylic levorotatory chiral agent.
9 . The polarizing plate as claimed in claim 8 , wherein the acrylic levorotatory chiral agent is 0.001 parts by weight to 10 parts by weight in amount relative to 100 parts by weight of the liquid crystal compound.
10 . The polarizing plate as claimed in claim 8 , wherein the acrylic levorotatory chiral agent is 0.1 parts by weight to 0.5 parts by weight in amount relative to 100 parts by weight of the liquid crystal compound.
11 . The polarizing plate as claimed in claim 1 , wherein the liquid crystal retardation layer has a thickness greater than or equal to 80% of a thickness of the retardation layer.
12 . The polarizing plate as claimed in claim 1 , further comprising:
at least one of a first protective layer or a second protective layer on the polarizer.
13 . An optical display apparatus comprising the polarizing plate as claimed in claim 1 .