Ion generating unit

摘要

An ion generating unit is made compact, yet avoids the undesired arc discharge for successfully generating the ions. The ion generating unit includes a dielectric base having a length and carrying a needle electrode and a ground electrode. The needle electrode has a pointed tip and is adapted to receive a high electric voltage relative to the ground electrode for electrically charging particles present in the surrounding air. The dielectric base being a polyhedron having multiple faces including a first face and a second face which are different from each other and have the length of the dielectric base. The needle electrode is mounted on or in a closely adjacent relation to the first face, and has its pointed tip directing forwardly along the length of the dielectric base with the pointed tip receded from the front end of the base. The ground electrode is mounted at the front end of the base in longitudinally spaced relation with the pointed tip. The ground electrode include anchor ends only by which the ground electrode is secured to the base. The anchor ends are fixed to the second face of the base, but not to the first face. Thus, the creepage distance between the electrodes extends over the first face and also the second face of the dielectric base, thereby being given an elongated distance relative to the air path between the electrodes for successfully generating the ions. <IMAGE>