| 摘要 |
In a preferred embodiment a lighting system contains a cathode 12 with an external surface 34 coated with an external cathode film 40 for the emission of electrons. A first anode 14 runs inside the cathode 12 to heat up the cathode in order to emit electrons from the external surface 34. A second anode 16 is arranged outside the cathode 12 to accelerate the electrons which are emitted from the external surface 34 of the cathode. A bulb body 18 surrounds the cathode 12, the first anode 14 and the second anode 16 in a hermetic seal. The bulb body contains a predetermined gas composition, the atoms of which are ionized by the electrons emitted by the cathode. The ionized atoms in the gas composition emit rays in the ultraviolet bandwidth of the electromagnetic spectrum. The bulb body 18 is coated with a fluorescing material 20 to trap the ultraviolet energy originating from the ionization of the atoms in the gas composition. The fluorescing material 20 emits rays in the visible bandwidth in the electromagnetic spectrum and emits a visible light. <IMAGE>
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