Light illuminating apparatus

Abstract

(Problem) To provide a small light illuminating apparatus configured to uniformly cool a plurality of light emitting diodes (LEDs) (Problem-solving approach) A light illuminating apparatus that irradiates light of a line shape includes a light source unit having a plurality of light sources arranged along a first direction on a surface of a substrate, a heat dissipation unit having a plurality of heat sink fins formed along the first direction, and thermally coupled to an opposing surface side of the substrate, a housing which receives the heat dissipation unit and forms a wind tunnel with a cooling wind flowing inside, wherein the cooling wind cools the heat sink fins, and a first cooling fan which generates the cooling wind flowing in the first direction within the wind tunnel, wherein at least one of opposite sides of a second direction of the housing has an air hole through which the cooling wind is discharged to outside via the plurality of heat sink fins, or the cooling wind is absorbed via the plurality of heat sink fins from outside, and the wind tunnel serves as a pressure chamber in which positive pressure or negative pressure is produced by the cooling wind.