| 摘要 |
<p>An ultrasonic probe adapted to carry out ultrasonic beam convergence by means of an acoustic lens. In the probe, in a hermetically sealed casing, at least portion constituting an ultrasonic incident and exit surface of which consists of a material ensuring appropriate sound transmission, two types of liquid layers that are mutually insoluble, exhibit different acoustic velocities and are conductive in one layer while insulating in the other layer are accommodated in the state of being superimposed one upon the other in the wave transmitting/receiving direction with an interface formed therebetween. Further, not only is a noncontact electrode covered with an insulating layer disposed around the two types of liquid layers, but also there is disposed a contact electrode brought into conductive contact with the conductive liquid layer. The configuration of the interface can be changed by voltage application between the noncontact electrode and the contact electrode, thereby rendering the focus of the acoustic lens variable.</p> |
