Patent ID: 6081070
Filing Date: 2000-06-27
Classification: H01J

Abstract:
An electrodeless fluorescent high-frequency lamp and fixture comprising:a bulbous lamp envelope and a reentrant cavity disposed in said envelope, a rare gas and vaporizable metal fill in said envelope, and a phosphor coating on the interior of the envelope for the generation of visible light;a lamp base disposed outside said envelope and said fixture, said fixture being attached to said lamp base;an induction coil for the generation of a plasma to produce radiation to excite said phosphor coating, said coil made from multiple strands of wire, said coil situated outside said envelope and fitted within said cavity;a ferrite core disposed inside said coil to increase the magnetic field generating in said plasma an azimuthal electric field igniting and maintaining said plasma;means to remove heat generated by said plasma from said cavity, said means being disposed in said cavity inside said ferrite and welded to the lamp base, said ferrite core and said coil whereby to redirect said heat to said fixture;means to suppress capacitive coupling between said coil and central tubulation to prevent the formation of a plasma inside said tubulation thereby reducing ion bombardment of the protective coating inside said tubulation thereby improving lamp maintenance; andan amalgam disposed in said tubulation to control metal vapor pressure in said envelope.