| 摘要 |
PROBLEM TO BE SOLVED: To completely evaporate the whole of the sealed mercury in lighting, sufficiently provide large intensity light radiation, and effectively prevent overheated state of a front base by providing a metal plate member having cooling air deflecting part in the front base. SOLUTION: A metal plate member 20 having a fixing cylinder part and a cooling air deflecting part is fitted around the outer circumference of the front base 15 of a mercury electric discharge lamp 10. The cooling air deflecting part of the metal plate member 20 has a projecting shape in the radial outward direction so as to deflect the cooling air flowing from the front in the direction separating from the optical axis, namely, deflect it in the radial outward direction of the fixing cylinder part. The metal plate member 20 is thus cooled down highly efficiently by the cooling air so that the base 15 of the lamp 10 is sufficiently cooled and the front side sealed tube part 11c is surely prevented from being in an overheated state. The cooling air deflecting part of the metal plate member 20 thus prevents the flow of the cooling air from directly blowing on the front face region of the central projecting part of the sealing body 11 of the lamp 10 so that the central projecting part is prevented from being overcooled and therefore the radiation intensity can be improved. |
