| 摘要 |
PURPOSE:To decrease the quantity of elastic deformation of a vibrator so as to prevent the breakage of a piezoelectric element at the time of catching the piezoelectric element by thickening the diameter on the inside periphery side of the vibrator. CONSTITUTION:A hollow metallic vibrator B has a thread part BB, which screws on a bolt extended to the top ab of an upper vibrator B, and a thread d, which enlarges the diameter of the vibrator B. The bottom BA of the lower vibrator B is fixed to one part of, for example, a camera or a printer, and the top BC is provided with a piezoelectric element C as an electric-mechanical energy conversion element. That is, at least, one side of the vibrator B is provided with a part whose inside diameter is larger than other part. Hereby, a crack does not occur in the piezoelectric element C when holding the piezoelectric element C, and vibration properties and efficiency can be improved. |
