| 摘要 |
PURPOSE:To enable the temperature of an outer tube to be efficiently controlled by providing a thermal-radiation-shielding plate made of a metal, glass, ceramics or the like between a space formed between the outer tube bulb and the inner tube. CONSTITUTION:A nickel plate of 2cm square used as an infrared-ray-shielding plate 13 is fixed in the middle between an outer tube 6 and an emission tube 7 by use of a band 11 and a supporting bar 12. When the temperature of the surface of the outer tube 6 is measured after the electric-discharge lamp is lit at room temperature (25 deg.C) and 20W, it is observed that the temperature of a part which is shaded by the shielding plate 13 is suppressed to around 40 deg.C although those of parts which are not shaded by the shielding plate 13 increase to 55 deg.C- 60 deg.C. Since such a shielding plate used for preventing the radiation of infrared rays doesn't require any nearly isolated space as a member which is used for preventing thermal conduction and convection, there is no need to install the shielding plate extremely close to the tube wall and to use a large plate which almost covers the sectional area of the tube. Therefore, the shielding plate can be manufactured easily. |
