JPH0152911B

PURPOSE:To measure displacement generated by a displacement generator precisely without reference to hysteresis characteristics that a displacement generating element has, by providing a means for detecting the displacement to a means for restraining the displacement of the displacement generating element. CONSTITUTION:A displacement generator 1 consists of an electrostrictive element 2 which is displaced by being applied with a driving voltage, bolts 3 which restrain the displacement of the electrostrictive element, and a strain gauge 4 which is adhered to the bolts 3 and detects strain generated at the bolts 3 by the displacement of the elecrostrictive element 2. A displacement position for the driving voltage E is found by measuring the output of the strain gauge 4. The bolt 3 is reduced in sectional area partially, where the displacement of the electrostrictive element 2 is generated to perform higher-precision displacement detection.