Annulus fluorescent lamp with overheat protection

An annulus fluorescent lamp, comprising:

• a plurality of annulus fluorescent tubes formed into shapes having different diameters and disposed substantially concentrically in substantially the same plane, each of the annulus fluorescent tubes having a first end with electrodes and outer lead wires and a second end without electrodes, the second ends of the annulus fluorescent tubes being communicated with each other via a bridge portion so that a single discharge path is formed inside the plurality of annulus fluorescent tubes;
• a mouthpiece covering the first and second ends of the annulus fluorescent tubes and having lead terminals;
• and
• an overheat protection component disposed in the mouthpiece and close to the electrode seal portion, the overheat protection component being connected electrically between at least one of the outer lead wires of the electrodes and one of the lead terminals of the mouthpiece, the overheat protection component being in thermal communication with the surface of the annulus fluorescent tubes at a portion close to the electrode seal portion via a resin, so that the overheat protection component cuts off current supply to the annulus fluorescent tubes corresponding to the heat conducted from the electrode seal portion via the resin when the electrode seal portion is overheated in a last period of the lamp life.