| 摘要 |
PURPOSE:To improve the luminous nonuniformity of a luminous tube and shorten the rise time at the time of lighting, by making small the diameter of an alumina made luminous tube enclosure gradually toward its end portions in comparison with its central portion and attaching tightly electrode conductors in the end portions of the luminous tube enclosure respectively. CONSTITUTION:The inside diameters phie of the end portions of an alumina made luminous tube enclosure 12 is set so as to be phie>=0.6phic to the inside diameter phic of its central portion, and the shape of the enclosure 12 is formed so that its diameter becomes gradually small toward its end portions in comparison with its central portion. Furthermore, tube-like electrode conductor 4, 5 made of niodium are attached directly and tightly in its both end portions respectively. As the difference of temperature between the central portion and the end portions becomes small thereby in comparison with it of a usual straight tube like enclosure, the luminous nonuniformity along the luminous tube can be improved, the rise time at the time of lighting can be shortened, and lamp efficiency can be improved. |
