Patent ID: 6288490
Filing Date: 2001-09-11
Classification: H01J

Abstract:
An electrodeless fluorescent lamp comprising:a glass lamp envelope formed of a tube in the shape of a closed loop, said tube having an inner surface and an outer surface;a filling of an inert gas and at least one vaporous metal selected from the group consisting of mercury, cadmium, sodium, the vapor pressure of said metal being below 10 torr during operation;a protective coating disposed on the inner surface of said envelope;a phosphor coating disposed on said protective coating;an induction coil formed of a plurality of parallel windings disposed on the outer surface of said envelope, said windings being disposed on planes parallel to the axis of said tube, said coil covering a small portion of the outer surface of said envelope;a radio-frequency power source coupled to said induction coil to ignite and maintain RF discharge in said envelope to generate a plasma.