| 摘要 |
PURPOSE:To provide clear ultrasonic image over a wide range by arranging two convergence type transducers so that they are matched with each other in the maximum direction of sound pressure distribution. CONSTITUTION:Ultrasonic waves through an acoustic lens 15 to a piezoelectric element 14 are passed from a common electrode 22 and an electrode 24 through a coaxial cable 18 for reception and extracted as electric signals. In this case, since the electrode is circularly formed, the first minimum of the sound pressure distribution on the focal surface of a convergence sound field is obtained by a diffraction effect and the sound field characteristics of reception sound waves become the ones for which no side lobe is present, a high sound pressure area is thick even at a focus and the high sound pressure area is further thickened in front and at the back of the focus. Thus, since the transmission/reception general sound field characteristics of this ultrasonic wave probe 11 become the sound field characteristics uniformly thin on a sound axis without the side lobe, when the ultrasonic images are obtained by using the probe 11, the clear images are obtained over the wide range and ultrasonic wave diagnostic performance is improved. Further, since complicated circuit constitution such as an electronic focus or the like is not required, constitution is simplified. |
