Patent ID: 8179029

Claim:
A light emitting device having at least a first and a second light emitting element, with the first light emitting element emitting a first light and the second light emitting element emitting a second light, each light emitting element being an OLED, the OLED comprising a sandwich structure with a substrate, a first and a second electrode and an organic layer being provided between the first and the second electrode, the organic layer comprising an organic material capable of emitting light, and a light leaving the light emitting device, wherein at least a part of said light is provided by a superposition of the first and the second light, wherein: the second electrode of the first or the second light emitting element is positioned between the organic layer and the substrate of the first or second light emitting element, respectively, the substrate of the first light emitting element is faced to the substrate of the second light emitting element, both substrates are optically coupled with a transparent medium, the substrate of the first light emitting element comprises a first refractive index n 1 and the substrate of the second light emitting element comprises a second refractive index n 2 , and the transparent medium has a refractive index n m , which is less than the refractive index of the first and the second substrate.