Patent ID: 7896524

Claim:
A light irradiation apparatus, comprising: an LED, an optical unit with an optical transmission characteristic that makes light from the LED pass through the inside thereof and makes it emit from its apical surface, and a supporting body having the LED installed on its apical surface, wherein the optical unit is in a shape of a rotating body centered in an optical axis of the light emitted from the LED, and is so configured that a base end recess for housing the LED is opened in a central part of its base end face, and a reflection plane for performing substantially total reflection of the light from the LED is formed on its side, and is further equipped with a position adjustment mechanism for adjusting a relative position between the LED and the optical unit along an optical axis direction, wherein the position adjustment mechanism makes the optical unit move relative to the LED between a proximity position at which a part or whole of the above mentioned supporting body is housed in a base end recess and a clearance position at which substantially the whole of the supporting body comes out of the base end recess and the apical surface of the supporting body and a base end face of the optical unit become substantially the same height, wherein the optical unit is so configured that a central convex lens part formed on its apical surface central part, a ring convex lens part with a different curvature formed on an apical surface in the periphery of the central convex lens part, and a curvilinear bulge surface acting as a reflection plane formed on its side, and the optical unit is so configured that at least at the proximity position, among the light rays emitted from the LED, substantially all the light rays passing through the side of the base end recess undergo total reflection on the curvilinear bulge surface and output them as mutually converging light rays through the ring convex lens part, while substantially all the light rays passing through a bottom of the recess emit to the outside as mutually converging light rays through the central convex lens part.