| 摘要 |
PURPOSE:To obtain a fluorescent lamp free of faults, e.g., blackish brown spots, by suppressing the occurrence of blakish brown spots by covering a transparent conductive film with a fluorescent substance containing a specific amount of manganese as an activator. CONSTITUTION:The inner surface of the glass tube is covered with the transparent conductive film 2 composed of tin oxide, etc., and then with the fluorescent substance 3 containing 0.5wt% or less manganese as an activator. Thus, when the fluorescent substance suffers a current impact, the formation of blackish manganese dioxide from the reaction of trace oxygen present in the tube with manganese is reduced and therefore blackish brown spots are greatly suppressed. Thus, a fluorescent lamp having no trouble, e.g., the occurrence of blackish brown spots, can be obtained. |
