| 摘要 |
PURPOSE:To provide an electrodeless discharge lamp which does not need large electric power supply for its starting auxiliary electrodes and has good starting properties. CONSTITUTION:A wire of an induction coil 2 is coiled on the outer circumference of a bulb 1 made of a transparent material and high frequency current is carried to the induction coil 2 from a high frequency electric power source 4. A discharge gas is sealed in the bulb 1 and a high frequency electromagnetic field in the surroundings of the induction coil 2 is applied to the discharge gas to excite the discharge gas and emit light. The bulb 1 is cylindrical and has a recessed part 1a in one bottom face. Two starting auxiliary electrodes 3a, 3b which are put along the coiled direction of the induction coil 2 are formed in the circumferential wall of the recessed part 1a. When high frequency voltage is applied to the starting auxiliary electrodes 3a, 3b, predischarge is generated. After that, when high frequency current is applied to the induction coil 2, the pre-discharge transfers to main discharge due to an induced electric field formed by the induction coil 2 and the lamp comes into lighting state. |
