Patent ID: 8894215

Claim:
An illumination unit, comprising: one or more light sources, each light source including a solid-state light-emitting device configured to emit light from a light emission region; and an optical member allowing the light incident from each solid-state light-emitting device to pass therethrough and exit therefrom, each solid-state light-emitting device including a single chip or a plurality of chips emitting the light, wherein the optical member includes an integrator having a first fly-eye lens on which the light from each solid-state light-emitting device is incident and a second fly-eye lens on which the light from the first fly-eye lens is incident, the integrator providing uniformity to an illuminance distribution of light in a predetermined illumination region illuminated by the light incident from each solid-state light-emitting device, each of the first fly-eye lens and the second fly-eye lens has a plurality of cells, the cells of the first fly-eye lens being arranged in a first direction and a second direction that intersect each other, positions of the cells in the second direction are different from one another at least partially among a plurality of cell rows arranged along the first direction in the first fly-eye lens, the positions of the cells in the second direction are shifted in a same direction between adjacent cell rows among the cell rows arranged along the first direction, and an amount “d” by which the cells are shifted between the adjacent cell rows satisfies a relational equation in which d=(h FEL1y /n x ), where h FEL1y is a size of one of the cells in the first fly-eye lens in the second direction, and n x is a number of cells in the first fly-eye lens in the first direction.