Patent ID: 8283850

Claim:
An electroluminescent element comprising a transparent substrate, and a first electrode layer, a light-emitting layer, and a second electrode layer, which layers are deposited on the substrate in this order, wherein a surface of the transparent substrate on the side of the first electrode layer has a light-directional structure, wherein the first electrode layer is prepared by deposition on the surface of the light-directional structure, wherein the light-directional structure comprises a microlens array, wherein the transparent substrate is a plate in the shape of a square or a rectangle, wherein the transparent substrate has the light-directional structure in both surfaces thereof, one of which is the surface of the transparent substrate directly contacting the first electrode layer and has a smaller refractive index than a refractive index of the first electrode layer, and another of which is the interface between the transparent substrate and the surrounding air, and wherein the microlens array comprises a plurality of microlenses, each with a height of 0.01 to 100 μm, arranged throughout the length and breadth of the transparent substrate at a pitch of 10 μm to 1 mm.