Compact lighting unit having a convoluted fluorescent lamp with integral mercury-vapor pressure-regulating means, and method of phosphor-coating the convoluted envelope for such a lamp

摘要

A fluorescent lamp having a multi-U-bent tubular envelope of convoluted configuration is combined with circuit means, a translucent protective cover and a base module to provide an efficient lamp unit of high brightness and long life that is compact enough to be used as a replacement for incandescent lamps in fixtures designed for residential and commerical lighting installations. Various spatial arrangements for including the ballast and starter components of the energizing circuit as integral parts of the compact lamp unit, despite the stringent space limitations, and also venting the cover and base module to provide convection cooling of the convoluted fluorescent lamp and the other electrical components are also disclosed. Tubulations provided on U-bent portions of the lamp envelope serve as phosphor-drainage means during lamp manufacture and are subsequently tipped off to form mercury-condensation chambers within the finished lamp that regulate the mercury-vapor pressure during lamp operation. The vapor-pressure regulating tubulations are so located relative to the vent openings in the lamp unit that they are exposed in the cool air which circulates through the lamp unit when the latter is energized and in use.