| 摘要 |
<p>Disclosed is a piezoelectric oscillator that generates traveling waves with two standing waves whereby the phases of modes B (1, n) (n is a natural number) differ by 90º. The piezoelectric element formation process, the polarization process and the manufacturing process can be simplified, and a structure that permits reduced cost is obtained. (4/3)n piezoelectric elements (5-16) are provided on the bottom surface of the piezoelectric oscillator to generate n wave traveling waves by synthesis of two standing waves, whereby the phases of modes B (1, n) differ by 90º, are provided on the underside of an oscillating body (4). Letting the wavelength of the traveling waves be l, the piezoelectric elements (5-16) have a circumferential length occupying a central angle corresponding to (1/2)??, and the multiple piezoelectric elements (5-16) are disposed at intervals occupying a central angle corresponding to (1/4)??. Each piezoelectric element comprises a piezoelectric body polarized in the thickness direction and a pair of electrodes formed on two sides of the piezoelectric body, and the direction of polarization of the piezoelectric body of the piezoelectric element in the circumferential direction is to one side or the other side in the thickness direction for every two elements.</p> |
