US Patent 7264375 Self-ballasted fluorescent lamp

A fluorescent lamp unit employing a fluorescent tube having a double spiral configuration is provided. The fluorescent lamp unit include a double spiral configured fluorescent tube having an upper central portion from which two spiral portions extend at a downward incline and wind around a vertical axis such that an outer diameter of the double spiral configuration increases as the spiral portions extends from the upper central portion to sealed ends of the fluorescent tube. The fluorescent lamp unit further includes a ballast housing having an electronic ballast contained therein. The ballast housing is partially enclosed by the spiral portions of the fluorescent tube.