PURPOSE: To provide an electrodeless electric drscharge lamp which can be easily started only by the electric conduction of the high frequency current in an inductive coil.
CONSTITUTION: A bulb 1 is an annular bulb body made of light transmissive material, and an inductive coil 2 is wound in the circumferential direction on the outside. A starting assisting member 3 consisting of dielectric is arranged over the whole peripheral surface surrounding the center hole of the bulb 1. When the inductive coil 2 is applied with high frequency current, a ring shaped inductive electric field is generated in the bulb 1, and the inductive electric field is acted on the electric discharge gas introduced into the bulb 1, and a streamer is generated. The streamer advances along the inner peripheral side of the bulb 1 close to the starting assisting member 3, and forms a loop. When the loop due to the streamer is formed, an inductive electric current flows, and the transition to the annular electric discharge is performed and light is emitted. Since the streamer is generated on the inner peripheral side in the inside space of the bulb 1, the length of the path to the loop is shortened, and the transition to the annular electric discharge is performed with less energy supplied.
WADA SEIGO
UKEKAWA MAKOTO
TOSAKA SHINGO
KOTANI MIKI
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