| 摘要 |
PURPOSE:To allow to increase the displacement amount without shortening the life time, by pressing an electrostrictive element by the atability of a flat spring. CONSTITUTION:A stainless plate 2 curved so as to generate height difference between the end parts and the center is set so that the concave surface may be opposed to the electrostrictive element 1 and extended by a pressing plates 3a and 3b and adhered on the element 1. In this constitution, because of the stability that the plate 2 restores to the original curved form when no drive, the compressive force is applied on the element 1. Next, when a high voltage is impressed between a lead wire 7 and the plate 2, a strong field is applied on the element 1 between an electrode 4 and the plate 2, and accordingly the element 1 contracts. On the other hand, the plate 2 is going to restore to the original curved form. Thereby, when drive, the element 1 and the plate 2 curve and displace a piece member 5 and a typing wire 6 upward resulting in typing. In this constitution, since the tensile stress generated in the element 1 when the displacement amount is increased by applying a strong field does not increase, the displacement amount can be increased without shortening the life time length. |
