ELECTROSTRICTION TRANSDUCER COMPRISING ELECTROSTRICTION LAYERS OF AXIALLY VARIED THICKNESSES

摘要

In an electrostriction transducer comprising protection layers (21, 22) in which no electric fields are produced during operation, each of end electrostriction layers (41, 42) which are contiguous to the respective protection layers with pertinent ones of internal electrodes (16, 17) interposed, is given a thicker thickness (at) as compared with other or intermediate electrostriction layers (23) to make the transducer have a long life and a high reliability. The intermediate electrostriction layers may have a common thickness (t). Alternatively, the intermediate electrostriction layers may have monotonously decreasing thicknesses when placed nearer to a plane which bisects a pile (19) of the electrostriction layers parallel to both end surfaces of the pile. When a pair of holding members for the transducer are used on both longitudinal ends, each protection layer is preferably received in an indent formed in the holding member. Alternatively, it is preferred that each holding member should comprise a metal plate contiguous to the protection layer and a metal band surrounding parts of the metal plate and the protection layer.