Driver for piezoelectric actuator and shutter control device utilizing

Abstract

There is disclosed a driving device for piezoelectric actuator, in which a voltage is applied to a piezoelectric actuator to generate a mechanical deformation therein, thus actuating a mechanical system. In an aspect, the piezoelectric actuator is at first given a voltage of inverse polarity, for generating a displacement in an opposite direction, and then given a voltage of forward polarity, for generating a displacement in the normal functioning direction, thereby actuating the mechanical system. Displacement and acceleration become larger, as the displacement of the actuator takes place from a position in the inverse direction. In another aspect, the electrical insulation state of the piezoelectric actuator is detected, and, if deteriorated, the destruction of insulation is prevented by an alarm generation and/or inhibition of voltage application. In an embodiment, the insulation state is identified from the ambient humidity of the actuator. In another aspect, if the detected humidity is at a high level that may induce destruction of insulation, the piezoelectric actuator is driven with a low voltage, in order to dehumidity by heat generation. Also shutter control devices for camera, utilizing piezoelectric actuator, are disclosed.