Actuator and electric toothbrush using the same

摘要

An actuator allows miniaturization by realizing back-and-forth rotating motion of, for example, an electric brush without a drive transmitting mechanism which constitutes a separate entity from a drive source. In a movable body (160) of this actuator (100), an outer yoke (110) is provided with inner wall planes (112a and 113a) located opposing each other spaced a predetermined interval apart and magnets (121 and 123) of different magnetic poles opposing each other in the inner walls planes (112a and 113a). The movable body (160) has a center yoke (140) located between the magnets (121 and 124) through air gaps. The movable body (160) is provided with a shaft (150). The fixed body (180) has a coil (170) which is located in the air gaps and which circles the center yoke (140). The fixed body (180) movably supports the movable body (160) through elastic bodies (190). An alternating current supplying section (195) supplies to the coil (170) the alternating current of a frequency virtually equal to the resonance frequency of the movable body (160).