| 摘要 |
<p>An ultrasonic probe which is used for ultrasonic diagnosis comprises a transducer element, a sonic speed control element, and an acoustic matching layer. The sonic speed control element has a function to control the sonic speed of the ultrasonic waves traveling therethrough, and has an inclined characteristic in the sonic speed control effect in which the sonic speed control effect changes continuously along the direction of travel of the ultrasonic waves (thickness direction). The specific acoustic impedance of the sonic speed control element at the end near the living body corresponds to the specific acoustic impedance of the acoustic matching layer at the end away from the living body. The acoustic matching layer is preferably formed by layering 2 or 3 or more overlapped members. The boundary between two adjacent members has a shape with a plurality of hills and valleys. The crossing angle between the direction of travel of the ultrasonic waves and the boundary is set so that a predetermined condition is satisfied. <IMAGE></p> |
