| 摘要 |
PURPOSE:To increase the degree of ventilation in a shell in which electric parts are installed so as to decrease the temperature rise of a discharge lamp device by providing the area of said shell through which air is introduced with a slant in such a manner as to decrease the thickness toward the end periphery. CONSTITUTION:The second shell 19 has a cylindrical section 20 which is connected to the outer periphery of the connection section 14 of the first shell 8. The inner surface of the cylindrical section 20 is provided with three projections 21 which correspond to and engage with the connection holes 15 of the first shell 8. A slant surface 22 becoming thin toward the end opening is formed on each of three middle areas formed between the three projections 21. In the shoulder section 24 of the second shell 19, a plural number of air holes 25 for thermal radiation are formed. Because of the above constitution, air is introduced from the thin end periphery of the slant surfaces 22 and exhausted through the air holes 25, thereby, causing convection to be easily produced. |
