Optical film and organic light emitting display apparatus including the same
View Patent ↗An optical film capable of preventing reflection of external light, and an organic light emitting display (OLED) apparatus including the same, are disclosed. The optical film is disposed on a substrate of an organic light emitting display, and comprises a first substrate, a first electrode, a light emitting unit comprising a plurality of organic light emitting elements, and a second electrode sequentially formed on the first substrate. The second substrate concentrates light emitted from the light emitting unit so as to emit outward, and absorbs external light so as to prevent the external light from being reflected.
1. An organic light emitting display (OLED) apparatus, comprising:
a first substrate;
an organic light emitting unit disposed on the first substrate and comprising a plurality of organic light emitting elements;
a second substrate covering the first substrate; and
an optical film disposed on the second substrate;
wherein the optical film concentrates light emitted from the light emitting unit so as to emit the concentrated light outward, and absorbs external light so as to prevent the external light from being reflected.
2. The apparatus of claim 1 , wherein the optical film comprises:
a plurality of microstructures; and
a light absorption unit disposed between the plurality of microstructures and absorbing external light;
wherein the microstructures concentrate light emitted from the OLED apparatus so as to emit the concentrated light outward, and
wherein the light absorption unit absorbs light incident from outside the OLED apparatus so as to prevent the incident light from being reflected.
3. The apparatus of claim 2 , wherein each of the plurality of microstructures comprises:
a first transmission unit disposed on a first surface of the optical film, and facing outward;
a second transmission unit disposed on a second surface of the optical film, which is opposite to the first surface; and
a reflection unit connecting the first transmission unit and the second transmission unit and forming a side wall of each of the plurality of microstructures;
wherein an area of the first transmission unit is smaller than an area of the second transmission unit.
4. The apparatus of claim 3 , wherein each of the first transmission unit and the second transmission unit transmits light.
5. The apparatus of claim 3 , wherein each of the first surface and the second surface is a smooth surface.
6. The apparatus of claim 3 , wherein the reflection unit reflects light transmitted through one of the first transmission unit and the second transmission unit and proceeding toward the reflection unit.
7. The apparatus of claim 3 , wherein the reflection unit is convex toward the first surface.
8. The apparatus of claim 2 , wherein internal portions of the plurality of microstructures are formed of a transparent resin material.
9. The apparatus of claim 8 , wherein a refractive index of the resin material continuously changes in a direction from the first surface toward the second surface.
10. The apparatus of claim 9 , wherein the refractive index of the resin material is increased in a direction from the first surface toward the second surface.
11. The apparatus of claim 1 , wherein a refractive index of the plurality of microstructures is greater than that of the light absorption unit.
12. The apparatus of claim 1 , wherein one organic light emitting element corresponds to a plurality of microstructures.
13. The apparatus of claim 1 , wherein a distance between the plurality of microstructures is greater than a distance between the plurality of organic light emitting elements.
14. The apparatus of claim 13 , wherein the distance between the plurality of microstructures is in a range of about 200 nm to 250 nm.