COMPACT-TYPE FLUORESCENT LAMP

摘要

Intended is to provide a compact-type fluorescent lamp having eight or more tubes using liquid mercury. The fluorescent lamp is enabled to lower the temperature of the vicinity of its base by forming such a portion at the leading end portion of a light-emitting tube as becomes the lowest of about 50 °C at the lighting time. The compact-type fluorescent lamp has eight or more U-shaped light emitting tubes but does not regulate the mercury vapor pressure. The fluorescent lamp is characterized in that the crest of at least one of the U-shaped tubes has such a section as is wider in the vicinity of the crotch of the U-shaped tube and as converges from the wider portion toward the leading end portion of the crest, and in that the axially inner size (L1) of the crest and the axially inner size (L2) between the wider portion near the crotch of the U-shaped tube and the leading end portion of the crest are: 11 = L1 = 17 (at the unit of [mm]) (1); and L1-7 = L2 = L1-2 (at the unit of [mm]) (2).