| 摘要 |
PROBLEM TO BE SOLVED: To suppress a change of an electretized amount caused by an ionizer irradiation of a dielectric film which is transduced to an electret and to reduce a change of sensitivity in a microphone. SOLUTION: A conductive substance 4 is not grounded to the earth, thereby a current path to an ionizer 1 is cut, and ions irradiated from the ionizer by an electric field generating by forming a loop circuit can suppress a drawing effect into a dielectric film 32. Therefore, an effect of reducing the change of the electrified amount caused by the ionizer 1 is attained, and a variation of the electrified amount decreases, thereby leading to a suppression of the change of sensitivity in the microphone. COPYRIGHT: (C)2010,JPO&INPIT |
