| 摘要 |
PROBLEM TO BE SOLVED: To provide an organic EL light emitting device utilizing light emission of an organic EL in which light extraction efficiency is improved. SOLUTION: The organic EL light emitting device 1 is provided with an organic EL layer 2 and a substrate 3 having translucency, and light from the organic EL layer 2 is extracted through the substrate 3. A gradient refractive index layer 4 which has a gradient so that the refractive index becomes higher as it goes from the substrate 3 side toward the organic EL layer 2 side is further provided between the organic EL layer 2 and the substrate 3. The gradient refractive index layer 4 has a convex part 45 which upheaves from the organic EL layer 2 side toward the substrate 3 side viewed in cross-section when the region having the same refractive index is seen, and these convex parts 45 are distributed adjoined plurally in the face. Thereby, since the light incident into the gradient refractive index layer 4 is refracted to the optical axis 46 direction of the convex part 45, the incident angle to the substrate 3 becomes small and reflection of light on the interfaces 31, 32 of the substrate 3 is prevented. COPYRIGHT: (C)2010,JPO&INPIT
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