Patent ID: 7038365

Claim:
An electrode-less fluorescent lamp having a 3-D structure comprising: a closed-loop tubular discharge tube enclosing a discharge gas, said tube being coated with a fluorescent layer on an inner surface and made of a light-transmissive material, wherein a center-line through said discharge tube forms a virtual closed-curved-surface of a 3-D structure in a 3-D space; at least one core surrounding at least a portion of said discharge tube; at least one coil wound around said at least one core, said coil supplying electromagnetic power to said discharge tube by producing a time-varying magnetic field in said core; and a radio frequency (RF) power source supplying RF power to said coil so that discharge generated in said discharge tube is maintained by said RF power, wherein said RF power generated by said RF source is supplied to said coil, said time-varying magnetic field is induced by said RF power supplied, and said electromagnetic power is supplied to said discharge tube via induced magnetic field, wherein said closed-loop tubular discharge tube comprises: two (2) U-shaped tubular parts; and a connecting part connecting said two U-shaped tubular parts to form a closed-loop, wherein said U-shaped tubular part comprises two straight tubular parts and a curved tubular part connecting said two straight tubular parts, said curved tubular part being at least partially surrounded by said core.