| 摘要 |
PURPOSE: To establish the predetermined mode pattern by arranging a plurality of piezo elements each having two disposed electrodes in a piezo structure, and giving reverse polarity distribution to the respective elements. CONSTITUTION: Reverse dipoles 12, 14 are distributed at four, six or eight poles in a piezo structure 10 to polarize a mode pattern. On the other hand, when two continuous electrodes are disposed at the respective sides of the structure, alternating tensile (expanding) and compressive (shrinking) strains are generated by the application of the fixed polarity DC voltage crossing these electrodes according to the direction of the predetermined polarity at the time of manufacturing and its space disposition. Further, when an alternating voltage is applied to regulate the frequency to a principle intrinsic value corresponding to the polarized pattern to the structure, the structure 10 is resonated to perform the displacement of the magnitude depending upon the drive voltage and the voltage coefficient of the strain and the attenuation loss in the structure. |
