Patent ID: 8610149

Claim:
An organic light emitting diode display, comprising: a substrate; a first electrode positioned on the substrate, wherein the first electrode is configured to substantially transmit visible light therethrough; an organic emission layer positioned on the first electrode; a second electrode positioned on the organic emission layer, wherein the second electrode is configured to substantially reflect visible light; and a semi-transmissive layer positioned between the substrate and the first electrode, wherein the semi-transmissive layer comprises a plurality of refractive sub-layers, wherein two abutting ones of the plurality of sub-layers have different refractive indices and wherein the plurality of sub-layers comprises a first refractive sub-layer positioned between the substrate and the first electrode and having a first refractive sub-index, and a second refractive sub-layer positioned between the first refractive sub-layer and the substrate, the second refractive sub-layer having a second refractive index that is greater than the first refractive index, wherein the thickness of the first refractive sub-layer and the thickness of the second refractive sub-layer are about the same.