| 摘要 |
PURPOSE:To decrease a level of radio noise, by forming an adhesive agent film layer, having powder of an inorganic insulating material, in at least an end part of at least either upper or lower side of a rotor electrode. CONSTITUTION:An adhesive agent film layer 16 is formed to the end upper side of a rotor electrode 15. This film layer 16 is formed in such a manner that, for instance, an adhesive agent used with water glass is mixed with powder of alumina as an inorganic insulating material, applied with this material and dried. This film layer 16 causes temperature of the electrode 15 to rise high with active emission of an electron, and a thermionic effect is activated. Accordingly, discharge voltage is lowered, and a capacitance discharge current is decreased to suppress generation of a radio noise arising from a spark discharge. Further an electric charge is stored between a conductor part of the electrode 15 and the film layer 16, and its residual charge effect loweres electric discharge voltage. |
