| 摘要 |
PURPOSE:To effectively and stably cool a light source so as to keep the temperature of the tube wall of the light source proper and to improve the light emitting efficiency of the light source by providing a blowing means for cooling the light source near the light source. CONSTITUTION:A fluorescent lamp holder 9 is mounted above a 1st scanner 8 and an opening part 10 is formed on the fluorescent lamp holder 9 so as to house a fluorescent lamp 12 which is the light source in it. A supporting plate 17 is mounted on the rear side of said holder 9 opposite to the opening part 10 in order to mount a cooling fan 18 consisting of an axial flow fan functioning as the blowing means which blows to the fluorescent lamp 12 and cools it on the plate 17. Moreover, a thermistor 19 functioning as a temperature detecting means for detecting the temperature of the tube wall of the fluorescent lamp 12 is attached to the outer peripheral surface of said holder 9. Thus, the light source can be effectively and stably cooled to keep the temperature of the tube wall of the light source proper and the light emitting efficiency of the light source can be improved. |
