Patent ID: 6362570
Filing Date: 2002-03-26
Classification: H01J

Abstract:
An electrodeless fluorescent lamp comprising:a glass lamp envelope formed of a tube having two sealed ends; a filling of 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 and a phosphor coating disposed on said protective coating; an inductive coil formed of a plurality of turns disposed on the atmospheric side of said tube along the wall of said tube in the axial direction, said turns being parallel to each other and disposed in planes, said planes being parallel to the axis of said tube at any cross section of said tube thereby generating a closed-loop axially uniform plasma in said tube; a radio-frequency (RF) power source coupled to said coil to ignite and maintain RF discharge in said envelope to generate a plasma.