Polarizing plate, method for preparing the same, and optical display apparatus including the same
First Claim
1. A polarizing plate, comprising:
- a polarizer, a half-wavelength (λ
/2) retardation film, and a quarter-wavelength (λ
/4) retardation film,wherein an absolute orthogonal b-coordinate value based on a CIELAB color coordinate system is approximately 3 or less when the polarizing plate is stacked with a reference polarizing plate having a degree of polarization of at least 99.9% such that an angle between an absorption axis of the polarizer and a reference absorption axis of a reference polarizer of the reference polarizing plate is 90°
,wherein at a wavelength of 550 nanometers, the quarter-wavelength (λ
/4) retardation film has an out-of-plane retardation value ranging from approximately −
100 nanometers to approximately −
130 nanometers, andwherein the out-of-plane retardation value (Rth) is calculated using the formula Rth=((nx+ny)/2−
nz)×
d, wherein nx, ny, and nz are refractive indexes in x-, y-, and z-axis directions of each retardation film, and d is a thickness of the retardation film.
1 Assignment
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Accused Products
Abstract
A polarizing plate includes a polarizer having absorption and transmission axes, a protective film on an upper surface of the polarizer, a half-wavelength (λ/2) retardation film on a lower surface of the polarizer, an adhesive layer on a lower surface of the half-wavelength (λ/2) retardation film, and a quarter-wavelength (λ/4) retardation film on a lower surface of the adhesive layer. An absolute orthogonal b-coordinate value based on a CIELAB color coordinate system of the polarizing plate may be approximately 3 or less when the polarizing plate is stacked with a reference polarizing plate having a degree of polarization of at least 99.9% such that an angle between the absorption axis of the polarizer and an absorption axis of a polarizer of the reference polarizing plate or an angle between the transmission axis of the polarizer and a transmission axis of the polarizer of the reference polarizing plate is 90°.
7 Citations
19 Claims
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1. A polarizing plate, comprising:
-
a polarizer, a half-wavelength (λ
/2) retardation film, and a quarter-wavelength (λ
/4) retardation film,wherein an absolute orthogonal b-coordinate value based on a CIELAB color coordinate system is approximately 3 or less when the polarizing plate is stacked with a reference polarizing plate having a degree of polarization of at least 99.9% such that an angle between an absorption axis of the polarizer and a reference absorption axis of a reference polarizer of the reference polarizing plate is 90°
,wherein at a wavelength of 550 nanometers, the quarter-wavelength (λ
/4) retardation film has an out-of-plane retardation value ranging from approximately −
100 nanometers to approximately −
130 nanometers, andwherein the out-of-plane retardation value (Rth) is calculated using the formula Rth=((nx+ny)/2−
nz)×
d, wherein nx, ny, and nz are refractive indexes in x-, y-, and z-axis directions of each retardation film, and d is a thickness of the retardation film. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method for preparing a polarizing plate, comprising:
-
preparing a polarizer comprising approximately 25 wt % to approximately 26 wt % moisture and approximately 20.5 wt % to approximately 22.5 wt % boric acid; and forming a protective film and/or a retardation film on at least one surface of the polarizer, wherein preparing the polarizer comprises; stretching a polyvinyl alcohol film in an aqueous boric acid solution comprising approximately 3.0 wt % to approximately 3.5 wt % boric acid, and drying the stretched polyvinyl alcohol film at a drying temperature of approximately 50°
C. to approximately 70°
C., and at an air volume having an air supply rate of approximately 1400 RPM to approximately 1500 RPM, and an air exhaust rate of approximately 2000 RPM to approximately 3000 RPM. - View Dependent Claims (13)
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14. An optical display apparatus comprising:
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a panel; and a polarizing plate stacked on an upper surface of the panel; wherein the polarizing plate comprises a polarizer having an absorption axis, a half-wavelength (λ
/2) retardation film on a lower surface of the polarizer, and a quarter-wavelength (λ
/4) retardation film on a lower surface of the half-wavelength (λ
/2) retardation film,wherein an absolute orthogonal b-coordinate value based on a CIELAB color coordinate system is approximately 3 or less when the polarizing plate is stacked with a reference polarizing plate having a degree of polarization of at least 99.9% such that an angle between the absorption axis of the polarizer and a reference absorption axis of a reference polarizer of the reference polarizing plate is 90°
,wherein at a wavelength of 550 nanometers, the quarter-wavelength (λ
/4) retardation film has an out-of-plane retardation value ranging from approximately −
100 nanometers to approximately −
130 nanometers, andwherein the out-of-plane retardation value (Rth) is calculated using the formula Rth=((nx+ny)/2−
nz)×
d, wherein nx, ny, and nz are refractive indexes in x-, y-, and z-axis directions of each retardation film, and d is a thickness of the retardation film. - View Dependent Claims (15, 16, 17, 18, 19)
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Specification