| 摘要 |
PURPOSE:To improve the performance of a rapid-start fluorescent lamp which contains a rare earth phosphor and is charged with a gas principally composed of Kr by specifying additives contained in the alumina protection film, the Nesa resistance and the fluorescent film. CONSTITUTION:The inner surface of a glass tube 1 is coated with a Nesa film 2 principally composed of tin oxide. The average resistance of the tube end portions of the Nesa film 2 each corresponds to 1/3 of the total length of the tube 1 is adjusted to at least 30kOMEGA/cm<2> and the average resistance of the remaining central portion of the tube 1 is adjusted to 1-10kOMEGA/cm<2>. Next, the Nesa film 2 is coated with an alumina protection film 3 composed of gamma-alumina and having a density of 0.01-0.1mg/cm<2>. Next, the film 3 is coated with a fluorescent film 4 principally composed of a rare earth phosphor and containing 1-4wt% of alpha-alumina. After that, the tube 1 is charged with a rare gas 6 principally composed of mercury 5 and Kr, thereby constituting a rapid-start fluorescent lamp. Therefore it is possible to improve both the decrease of the electromotive voltage of the lamp and its inferior appearance caused by Hg staining without causing any discrepancy. |
