Patent ID: 7796209

Claim:
An illumination device comprising: a plurality of pairs of a light source and a light guide plate, the light guide plate receiving light from the light source, diffusing the light, and performing surface emission of the light, the light guide plate including: a light-emitting section having a light-emitting surface from which the light is emitted; and a light guide section for guiding, to the light-emitting section, the light from the light source, the light guide plates being adjacent to one another in such a manner that a light-emitting section of one light guide plate on one side is disposed on a light guide section of a light guide plate adjacent thereto on the other side, wherein: the light-emitting surface includes: a parallel surface parallel to an irradiation object; and a slant surface slanted relative to the irradiation object, the slant surface being provided between the parallel surface and the light guide section of the light guide plate; and the slant surface has gradients varying continuously relative to the parallel surface in such a manner as to form a curved surface continuously connected with the parallel surface.