| 摘要 |
An upper electrode (50) includes a first electrode (51) formed in a circle and a second electrode (52) formed in an annulus outside the first electrode (51). The first electrode (51) and the second electrode (52) are electrically separated from each other via an insulating region. A lower electrode (30) includes a third electrode (31) formed in a circle and a fourth electrode (32) formed in an annulus outside of the third electrode (31). Similarly, the third electrode (31) and the fourth electrode (32) are electrically separated from each other via an insulating region. Further, the third electrode (31)is provided so as to face the first electrode (51) via the piezoelectric body (40) and the fourth electrode (32) is provided to face the second electrode (52) via the piezoelectric body (40), respectively.
|
