| 摘要 |
<p>PURPOSE:To make it possible to cool effectively, by fitting the both ends of a fluorescent discharge tube to the both fitting parts formed at an end surface of a base, and contacting only partially to allow a ventilation without contacting the all periphery of the fluorescent discharge tube. CONSTITUTION:An almost cylindrical sleeve 16 is fitted to a fluorescent discharge tub 1, and the radiating opening of the sleeve 16 is faced to a luminous display portion 2 of the fluorescent discharge tube 1, in the horizontal direction to the axial direction. At the radiation opening of the sleeve 16, a lens 17 formed by a glass or the like is furnished watertight, and an airing passage 18 is formed between the inner surface of the sleeve 16 and the outer surface of an almost rectangular base 3. The cooling air from the rear side of the luminous display flows through the airing passage 18 between the sleeve 16 and the base 3 into the sleeve 16, and cools all the fluorescent discharge tube 1, while the air flowing in from the airing inlet 6 is exhausted through the gap of the fitting portions 4 and 5 to cool the end of the fluorescent discharge tube 1.</p> |
