PROBLEM TO BE SOLVED: To appropriately control the temperatures of a cooling base part and an arc tube part at turning off a low-pressure gas discharge lamp.SOLUTION: In an ultraviolet irradiation apparatus which includes the low-pressure mercury gas discharge lamp (17) where the cooling base part (15) for controlling a mercury vapor pressure in the arc tube part (10) is provided at the end of the arc tube part (10), a first cooling device (31) for cooling the cooling base part (15), a second cooling device (32) for cooling the arc tube part (10), a lighting device (20) for turning on and off the low-pressure mercury gas discharge lamp (17) when receiving a turn-on signal and a turn-off signal, and a control part (40) for controlling the first cooling device (31), the second cooling device (32), and the lighting device (20), when the control part (40) receives the turn-off signal, it controls the operational states of the first cooling device (31) and the second cooling device (32) while the low pressure mercury gas discharge lamp (17) is lit so that a temperature gradient between the cooling base part (15) and the arc tube part (10) is small, and then makes the lighting device (20) turn off the low-pressure mercury gas discharge lamp (17).COPYRIGHT: (C)2011,JPO&INPIT【課題】低圧蒸気放電灯の消灯時に冷却ベース部の温度及び発光管部の温度を適切に制御する。【解決手段】発光管部(10)の端部に発光管内の水銀蒸気圧を制御するための冷却ベース部(15)を備えた低圧水銀蒸気放電灯(17)、冷却ベース部を冷却する第一の冷却装置(31)、発光管部を冷却する第二の冷却装置(32)、点灯信号及び消灯信号を受けて低圧水銀蒸気放電灯の点灯及び消灯を行なう点灯装置(20)、並びに第一の冷却装置、第二の冷却装置及び点灯装置を制御する制御部(40)を備えた紫外線照射装置において、制御部が、消灯信号を受けると、放電灯を点灯させたまま冷却ベース部の温度と発光管部の温度の温度勾配が小さくなるように第一の冷却装置及び第二の冷却装置の動作状態を制御した後に、点灯装置に低圧水銀蒸気放電灯を消灯させるよう構成した。【選択図】図3
