| 摘要 |
In an inner bottom surface of a case (31), a substantially oblong recess (40) having a long axis and a short axis forms a vibration area (VA). A piezoelectric element (37) is bonded to the center of the recess (40). On the opposite sides of the vibration area (VA), vibration suppression areas (SVA) thicker than the vibration area (VA) are disposed. A side portion of the case (31) is formed to be thin over the entire circumference. A reinforcing member (41) higher in rigidity than the case (31) is bonded to upper portions of the vibration suppression areas (SVA). The reinforcing member (41) has a bottom surface substantially equal to the shape of the vibration suppression areas (SVA), and has a predetermined height. A gap between the reinforcing member (41) and an inner side surface of the case (31) is also filled with a filling member (35). |
