US Patent 7245436 Illumination device and projector

An illumination device includes a light source, a first lens array having a plurality of first small lenses, a second lens array having a plurality of second small lenses corresponding to the plurality of first small lenses, and a superimposing lens. The plurality of first small lenses is made eccentric in a certain direction while the plurality of second small lenses is made eccentric in one of the certain direction and a direction orthogonal to the certain direction. The first and second lens arrays are integrally formed into one light-transmissive member.