| 摘要 |
PROBLEM TO BE SOLVED: To provide a light irradiation apparatus capable of irradiating an outer peripheral surface of a drum with ultraviolet light of a plurality of wavelengths whose peak intensities are aligned.SOLUTION: A light irradiation apparatus, which irradiates a sheet-like irradiation target moving along a part of an outer peripheral surface of a cylindrical drum in a closely contact manner with light, comprises a plurality of optical units which have: a light source part which consists of a plurality of light-emitting elements arranged on a substrate along a first direction and a second direction; and a pair of rectangular reflection mirrors which is arranged so as to sandwich optical axes of the plurality of light-emitting elements from the second direction, guide light from the light source part by a pair of reflection mirrors, and emit light of a predetermined spread angle and light quantity to the drum. The plurality of optical units consist of N×M pieces (M denotes an integer of 1 or more) of optical units which emit N types (N denotes an integer of 2 or more) of light having different wavelengths, each emission surface of N×M pieces of the optical units is arranged on a predetermined reference plane, and a distance between the pair of reflection mirrors of each optical unit is set based on a distance from a reference plane of the optical axis to the outer peripheral surface of the drum. |
