FLUORESCENT LAMP AND LUMINAIRE

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PROBLEM TO BE SOLVED : To provide a fluorescent lamp capable of controlling mercury vapor pressure so as not to lower the emission efficiency in either of a low-temperature area and a high-temperature area. SOLUTION : The fluorescent lamp comprises : at least a pair of straight-line portions 1a, 1b having a length of 1, 000 mm or more and extending in proximity to each other; a communicating part 1b for allowing the pair of straight-line portions 1a, 1b to communicate with each other at one of ends thereof; and a pair of electrodes 2, 2 sealed at a position located on the side of the other ends of the pair of straight-line portions 1a, 1b and at a distance T from those other ends. The fluorescent lamp further comprises : a translucent discharge vessel 1 disposed to satisfy 0.5T≤H≤4T where H is the distance from one of the ends of each of the straight-line portions 1a, 1b to a center of a discharge path of the communicating part 1b; a phosphor layer 4 formed on an inner surface of the translucent discharge vessel 1; and a rare gas enclosed in the translucent discharge vessel 1. Since the coolest portion is formed in the translucent discharge vessel 1 on the side of the one of the ends of each of the straight-line portions 1a, 1b, it is possible to allow a flux of light to rise rapidly at the start of lighting.