| 摘要 |
<p>An ultrasonic transducer which constitutes with good reproducibility an acoustic impedance matching member in which the acoustic impedance gradually changes is characterized in that the acoustic impedance matching member (2) is constituted by laminating a number of unit layers (21, 22, 23, ----, 2n) each having a thickness much smaller than one fourth of the wavelength of ultrasonic waves, that each unit layer consists of a laminate of a heavy metal layer (52) and a plastic layer (51), and that the ratio of the thickness of the heavy metal layer to the thickness of the plastic layer gradually changes from the unit layer of the side that comes into contact with the ultrasonic vibrator toward the unit layer of the side that comes into contact with a material to be inspected.</p> |
