Optical filter for anti-reflection and organic light-emitting device
The present application relates to an optical filter and an organic light-emitting display device. The optical filter of the present application has excellent omnidirectional antireflection performance and color characteristics on the side as well as the front, and the optical filter can be applied to an organic light-emitting device to improve visibility.
1. An optical filter for anti-reflection comprising:
a polarizer having an absorption axis formed in one direction,
a first retardation film having reverse wavelength dispersion characteristics and quarter-wave phase retardation characteristics,
a second retardation film satisfying Equation 1, sequentially, and
further comprising an optical compensation layer between the polarizer and the first retardation film, wherein the optical compensation layer comprises a third retardation film having an in-plane slow axis that is parallel or orthogonal to the absorption axis of the polarizer, and having an Nz value for light of a wavelength of about 550 nm of 1.2 to 1.2 in Equation 8:
nx=ny<nz Equation 1:
Nz =( nx−nz )/( nx−ny ) Equation 8:
wherein, nx, ny, and nz are refractive indexes in the x-axis, y-axis and z-axis directions of the retardation film, the x-axis is a direction parallel to the in-plane slow axis of the retardation film, the y-axis is a direction parallel to an in-plane fast axis of the retardation film, and the z-axis is a thickness direction of the retardation film.
2. The optical filter according to claim 1 , wherein the first retardation film is a retardation film satisfying Equation 2, 3 or 4 below:
ny<nx≠nz Equation 2:
nx>ny>nz Equation 3:
nx>ny=nz Equation 4:
wherein, nx, ny and nz are refractive indexes in the x-axis, y-axis and z-axis directions of the retardation film, the x-axis is a direction parallel to the in-plane slow axis of the retardation film, the y-axis is a direction parallel to an in-plane fast axis of the retardation film, and the z-axis is a thickness direction of the retardation film.
3. The optical filter according to claim 1 , wherein the first retardation film has an in-plane retardation of 130 nm to 150 nm for light having a wavelength of 550 nm.
4. The optical filter according to claim 1 , wherein the first retardation film has an R (450)/R (550) of 0.60 to 0.92, and R (λ) means an in-plane retardation of the retardation film for light of λ, nm.
5. The optical filter according to claim 1 , wherein the third retardation film has an in-plane retardation for light of a wavelength of about 550 nm of 70 nm to 200 nm.
6. The optical filter according to claim 1 , wherein the third retardation film has an Nz value of from −1 to 1.
7. The optical filter according to claim 1 , wherein the third retardation film has an Nz value of −0.2 to 0.8.
8. The optical filter according to claim 1 , wherein the third retardation film has an in-plane slow axis parallel to the absorption axis of the polarizer, an in-plane retardation for light of a wavelength of about 550 nm of 70 nm to 180 nm and an Nz value of −0.2 to 0.8, and the second retardation film has a thickness-direction retardation of 70 nm to 120 nm.
9. The optical filter according to claim 1 , wherein the third retardation film has an in-plane slow axis orthogonal to the absorption axis of the polarizer, an in-plane retardation for light of a wavelength of about 550 nm of 100 nm to 200 nm and an Nz value of −0.4 to 0.6, and the second retardation film has a thickness-direction retardation of 100 nm to 160 nm.
10. An organic light-emitting device comprising the optical filter of claim 1 and an organic light-emitting display panel.
11. The organic light-emitting device according to claim 10 , wherein the first retardation film of the optical filter is disposed adjacent to the organic light-emitting display panel as compared with the polarizer.
12. An optical filter for anti-reflection comprising:
a polarizer having an absorption axis formed in one direction,
a first retardation film having reverse wavelength dispersion characteristics and quarter-wave phase retardation characteristics, wherein an in-plane slow axis of the first retardation film forms 43 degrees to 47 degrees with the absorption axis of the polarizer,
a second retardation film satisfying Equation 1, sequentially, and
further comprising an optical compensation layer between the polarizer and the first retardation film, wherein the optical compensation layer comprises a third retardation film having an Nz value for light of a wavelength of about 550 nm of −1.2 to 1.2 in Equation 8:
nx=ny<nz Equation 1:
Nz =( nx−nz )/( nx−ny ) Equation 8:
wherein, nx, ny, and nz are refractive indexes in the x-axis, y-axis and z-axis directions of the retardation film, the x-axis is a direction parallel to the in-plane slow axis of the retardation film, the y-axis is a direction parallel to an in-plane fast axis of the retardation film, and the z-axis is a thickness direction of the retardation film.
13. An optical filter for anti-reflection comprising:
a polarizer having an absorption axis formed in one direction,
a first retardation film having reverse wavelength dispersion characteristics and quarter-wave phase retardation characteristics,
a second retardation film satisfying Equation 1, sequentially, wherein the second retardation film has a thickness-direction retardation for light of a wavelength of about 550 nm of 70 nm to 160 nm, and
further comprising an optical compensation layer between the polarizer and the first retardation film, wherein the optical compensation layer comprises a third retardation film having an Nz value for light of a wavelength of about 550 nm of −1.2 to 1.2 in Equation 8:
nx=ny<nz Equation 1:
Nz =( nx−nz )/( nx−ny ) Equation 8:
wherein, nx, ny, and nz are refractive indexes in the x-axis, y-axis and z-axis directions of the retardation film, the x-axis is a direction parallel to the in-plane slow axis of the retardation film, the y-axis is a direction parallel to an in-plane fast axis of the retardation film, and the z-axis is a thickness direction of the retardation film.