Light source having an outsource device

摘要

The invention relates to a light source (1) comprising a light generating unit (2) like an organic light emitting diode and an outcoupling device (3) for coupling light out of the light generating unit in an outcoupling direction (4). The outcoupling device comprises a first region (5) for facing the light generating unit, a second region (7) having a refractive index being smaller than the refractive index of the first region, and a structured intermediate region (6) between the first region and the second region. The first region is optically homogenous and has a thickness in the outcoupling direction being larger than a coherence length of the light, thereby reducing generally possible wavelength dependent interference effects and, thus, a corresponding degradation of the outcoupling efficiency. The outcoupling efficiency can therefore be increased.

主权项

1. A light source comprising: a light generating unit for generating light, and an outcoupling device for coupling light out of the light generating unit in an outcoupling direction, wherein the outcoupling device comprises: a first region for facing the light generating unit, the first region being optically homogenous and having a thickness in the outcoupling direction being larger than 10 pm, a second region having a refractive index being smaller than the refractive index of the first region, and an intermediate region between the first region and the second region, the intermediate region being structured, wherein the intermediate region comprises particles for structuring the intermediate region, the particles having a refractive index being equal to or smaller than the refractive index of the second region or larger than the refractive index of the first region; and wherein the particles are distributed on and attached to the surface of the second region.