Abstract: An illumination apparatus includes a plurality of LED chips arranged to form an LED array, light from the plurality of LED chips superimpose to project a light intensity distribution projected on the predetermined plane; a pair of lens arrays each including a plurality of lenses and configured to collect light from the LED arrays; a driving unit configured to adjust a distance between the pair of lens arrays and change the light intensity distribution projected on the predetermined plane; and a control unit for individually controlling the output of the first and second LED arrays.

Abstract: A light intensity distribution on an irradiation target plane is adjusted to a desired distribution using a light source device that includes a light-emitting diode (LED) array. A light source device that includes an LED array in which a plurality of LED chips is arranged and forms on a predetermined plane a light intensity distribution obtained by superimposing light intensity distributions of light from the plurality of LED chips includes a pair of lens arrays including a plurality of lenses configured to collect light from the plurality of LED chips, wherein a distance between the pair of lens arrays is changed, thereby changing the light intensity distribution to be formed on the predetermined plane.