| 主权项 |
1. An ultraviolet irradiation head comprising
a substrate, multiple ultraviolet LED elements arranged on the substrate, a heat sink thermally connected to the substrate, and a fan unit, the heat sink including a fin segment formed of multiple fins aligned in a direction in which the ultraviolet LED elements are aligned, and wherein in operation, cooling air travels from the fan unit and acts on the fin segment to cool the ultraviolet LED elements, wherein the fan unit is arranged near a distal end of the fin segment,
a vent hole is formed in a case of the irradiation head, and the vent hole is formed to expose a base end of the fin segment entirely in the direction in which the fins are aligned, wherein the vent hole is formed over gaps between all of the fins,and wherein a flow path area of the cooling air flowing through the vent hole is less than a flow path area of the cooling air flowing through the gaps between all of the fins,the heat sink is configured such that each gap between the fins is substantially blocked in a part other than where the vent hole is present,the gap is an opening extending in a width direction perpendicular to the direction in which the fins are aligned, andspace between the distal end of the fin segment and the fan unit functions as a pressure chamber that is placed in a positively pressurized condition or a negatively pressurized condition by the cooling air from the fan unit. |
