| 摘要 |
<p>This ultrasonic sensor is provided with: a bottomed cylindrical case (51) having an opening, a bottom portion, and a side wall portion; a piezoelectric element (52), bonded to the inner surface of a bottom portion (51b) of the case (51); and filling materials (55, 56) that are applied to the inside of the case (51). A vibration region including a bonding position of the piezoelectric element (52), and a thick portion (51r), which is disposed on the outer circumference of the vibration region, and which is thicker than the vibration region, are provided on the inner side of the bottom portion of the case (51). A reinforcing material (57) having higher rigidity than the bottom portion of the case is disposed on the thick portion (51r). The thick portion (51r) is continuous over the whole circumference in the circumferential direction of the bottom portion of the case (51). With such structure, vibration amplitude of the vibration region is increased, and sensitivity of the ultrasonic sensor is improved.</p> |
