| 摘要 |
PURPOSE:To improve the luminous efficacy of a lamp and obtain the sufficient brightness of it by setting a filament electrode within 10mm. from the end of the lamp in a fluorescent lamp which has a total length of less than 120mm. and has a power consumption of less than 1.5W. CONSTITUTION:A glass enclosure 1, which contains a very small amount of mercury, argon gas, etc., is made less than 120mm. in its total length L, and less than 8mm. in its inner diameter D, and a fluorescent substance is coated on its inner wall surface. And a filament 2 made of tungsten and others is set within 10mm. from the end of the enclosure 1, and further a thermal insulating material 4 is applied on the surface of the enclosure 1 in the vicinity of the filament 2; thus a small-size fluorescent lamp with a power consumption of less than 1.5W is formed which is used as the back light of a liquid crystal element, etc. In this way, the coldest point at the time of lighting the lamp is located behind and near the filament 2, and the temperature can be easily raised. This makes it possible to raise the vapor pressure of mercury and improve the liminous efficacy. |
