Apparatus and method for effecting fine movement by impact force produced by piezoelectric or electrostrictive element.

摘要

An apparatus for effecting a fine movement of an object by making use of impact produced by a piezoelectric/electrostrictive element (11), which has a moving member (12), the piezoelectric/electrostrictive element (11) is attached to the moving member (12), means (16, 17) for driving the piezoelectric/electrostrictive element (11), and an inertia member (13) operative in response to the driving of the piezoelectric/electrostrictive element (11) so as to impart an impact to the moving member (12). As an electric field is applied to the piezoelectric/electrostrictive element (11), a strain is caused by a stress which acts to expand or contract the piezoelectric/electrostrictive element (11) to a length determined by the level of the electric field. By making use of this phenomenon, impact is produced by the inertia member (13) which operates in response to the stress, thereby effecting a step-like fine movement of the moving member (12). Thus, the inertia member (13) is impactingly driven by elongation or contraction of the piezoelectric/electrostrictive element (11) so that a reactional force overcomes the friction acting between the moving member (12) and a base so as to realize a fine movement of the moving member (12).