| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide first a fluorescent lamp which has small dark portion at the lamp end part, and secondly, a fluorescent lamp which has a high luminous efficiency by making a positive column long. Ž<P>SOLUTION: The fluorescent lamp 100 is provided with a glass tube 1, which has a fluorescent face 2 made of phosphor on the inner face and seals both ends and introduces at least rare gas to be sealed, lead wires 4a, 4b, 4c, 4d which penetrate both end parts of the glass tube 1, respectively by a pair; a filament 5 which is fixed respectively at the inside end of the pair of lead wires 4a, 4b, 4c, 4d; and a cover 8, which covers the center side and the side face part of the glass tube 1 of the filament 5 and has an opening part 8b on the end part side of the glass tube 1. The shortest distance between the end on the center side of the glass tube 1 of the filament 5 and a plane perpendicular to the center line of the glass tube 1, including at least a part of the opening part 8b of the cover 8, is 5 mm or larger. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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