Patent ID: 7671512

Claim:
An impact drive actuator comprising: a vibrating base plate configured to be slightly displaced in a reciprocating manner by a vibrator in a first direction and a second direction opposite to the first direction; a first slider and a second slider disposed on the vibrating base plate; a first electrode, a fourth electrode and a fifth electrode formed on the vibrating base plate; a second electrode and a third electrode so formed on the first slider and the second slider as to face the first, fourth and fifth electrodes through an insulation film; and a potential difference generator configured to generate a potential difference between the first electrode and the fifth electrode to allow a first electrostatic attractive force to act between the vibrating base plate and first slider by applying a voltage between the first electrode and the fifth electrode, and configured to generate a potential difference between the fourth electrode and the fifth electrode to allow a second electrostatic attractive force to act between the vibrating base plate and the second slider, by applying a voltage between the fourth electrode and the fifth electrode, wherein when the vibrator reciprocates the vibrating base plate, the potential difference generator causes an electrostatic force to act between the first electrode, the fifth electrode and the second electrode, by which a frictional force acting between the first slider and the vibrating base plate is changed, and to act between the fourth electrode, the fifth electrode and the third electrode, by which a frictional force acting between the second slider and the vibrating base plate is changed, thereby adjusting a displacement amount of the first slider and a displacement amount of the second slider, and the time needed to displace the vibrating base plate in the first direction and time needed to displace the vibrating base plate in the second direction differ from each other, and the first slider and the second slider are displaced relative to the vibrating base plate in the direction where the time needed for displacement is larger.