Substrate for optical element, organic electroluminescence element and organic electroluminescence display device
View Patent ↗The present invention uses a substrate for an optical element comprising a light scattering unit that scatters visible light, and a light transmissive opening that transmits the visible light in a light transparent substrate transmitting the visible light, as a light extraction substrate of the organic electroluminescence element. With this, a substrate for an optical element, an organic electroluminescence element, and an organic electroluminescence display device are provided that improves the light extraction efficiency to outside of the substrate and also improves the light extraction efficiency by obtaining a high luminance organic electroluminescence element.
1. A substrate for an optical element, comprising
a light scattering unit that scatters visible light, and a light transmissive opening that transmits the visible light in a light transparent substrate transmitting the visible light;
wherein a length L of the light scattering unit in a thickness direction of the substrate and a width W of the light transmissive opening is found by the following equation:
W/L ≦tan(arc sin( n 1 /n 2))
where n1 indicates a refractive index of air and n2 indicates a refractive index of the light transparent substrate.
2. The substrate according to claim 1 ,
wherein a surface of the light scattering unit has the same surface as the light transparent substrate.
3. The substrate according to claim 1 ,
wherein the light transmissive opening is formed in the light transparent substrate, by being segmented by at least the light scattering unit, and
wherein the light transmissive opening is periodically placed in a direction of the substrate surface.
4. The substrate according to claim 1 , wherein the substrate for the optical element forms at least one display pixel, and the light scattering unit extends in at least one direction in the display pixel.
5. The substrate according to claim 4 , wherein the light scattering unit is a wall structure that segments the display pixel.
6. The substrate according to claim 5 , wherein the light transmissive opening segmented by the wall type structure is periodically placed in the direction of the substrate surface.
7. The substrate according to claim 1 , wherein the width W of the light transmissive opening is 100 nm to 20 μm.
8. The substrate according to claim 3 , wherein the light transmissive opening is periodically placed in the direction of the substrate surface, and the sum of the thickness of the segmenting wall and the width of one light transmissive opening adjacent to the segmenting wall is 130 nm to 25 μm.
9. An organic electroluminescence element, comprising the substrate for an optical element of claim 1 , an anode, an organic layer made of at least an emission layer, and a cathode.
10. An organic electroluminescence display comprising a plurality of the organic electroluminescence elements of claim 9 .