摘要 |
PURPOSE:To contrive to improve the effect of restricting the discharge in a discharge region in an electrode by forming a constitution wherein only a region which does not allow the discharge of an electrode coated with a dielectric such as a glass is coated with a fluoric polymer. CONSTITUTION:A ground side electrode and a high voltage side electrode are constituted by coating the surface of a metallic tube 8 with the dielectric 16 of a high dielectric constant composed of a dielectric such as a glass. Only the region which does not allow the discharge on this dielectric 16 is coated with a dielectric 17 of a low dielectric constant using the fluoric polymer. When a voltage is impressed between both the electrodes of the ground side electrode and the high voltage side electrode constituted in such a manner, the potential difference of which each dielectric takes charge differs with regions coated with both of the dielectrics; at the region coated with the dielectric 17, a large potential difference generates by the existence of the fluoric polymer layer, and a discharge does not occur. Thereby, the effect of controlling the discharge can be remarkably improved by the simple electrode structure. |