Patent ID: 7920227

Claim:
An illumination device comprising: a light-emitting layer in which a plurality of light sources are scattered; and a diffusion layer that is formed on the light-emitting layer and diffuses light from the light-emitting layer, the diffusion layer having a transmittance of light in an area close to each of the light sources which transmittance is smaller than a transmittance of light in an area that is far from each of the light sources, the light sources each having directivity in a light emission direction, the directivity being such that a light component in a direction parallel to a boundary surface between the light-emitting layer and the diffusion layer is larger than a light component in a direction perpendicular to the boundary surface, and a plurality of unit structures each of which is made up of two of the light sources that are arranged to face each other, and are alternately arranged so that the light sources of unit structures that are adjacent to one another are not in alignment with one another.