Ring-form two-dimensional (X-Y) moving piezoelectric actuator

This paper deals with a ring-form two-dimensional (X-Y) moving piezoelectric actuator. Use of this actuator enables, for example, a short distance stroke of a few mm for a lens in a camera. The actuator has two moving functions of rotational and linear motions. A combination of these two functions drives the actuator effectively; that is, such functions wherein first, the moving direction angle is determined by the rotational motion and next, the linear motion gives the straight moving distance, can be made possible. The actuator is constructed using a ring-form piezoelectric multimode vibrator in which three resonance modes degenerate: two of them are B-21 and B-21' bending modes of the same form which have two nodal circles and a nodal diameter, and the other is the first radial vibration mode (R,1). In this paper, the operation principle of the actuator and its basic characteristics of Linear and rotational motions are shown, and moreover, the driving force characteristics are also presented and quantified.