| 摘要 |
PURPOSE:To arbitrarily set the focal direction of an ultrasonic wave by arranging plural pieces of first to n-th piezoelectric pieces in the width direction, connecting in common the piezoelectric pieces successively from both end sides such as a first one and an n-th one, and a second one and an n-1-th one and driving to delay them, and varying a focal distance by controlling a delay time. CONSTITUTION:The ultrasonic probe is constituted by arranging plural pieces (1-n), for instance, nine pieces (a-i) of piezoelectric pieces 4 consisting of PZT on a line. Also, by connecting in common electrodes (not shown in the figure) of one principal plane, it is constituted as a transmitting/receiving plane of an ultrasonic wave. Moreover, from the other principal plane, lead wires are led out, respectively, and the probe is constituted by connecting in common the piezoelectric pieces 4 successively from both end sides such as (a) and (i), (b) and (h), (c) and (g), and (f) and (e). That is, when (n) pieces of piezoelectric pieces are arranged, the probe is constituted by connecting in common an (m)-th piece and an (n-m+1)-th piece. According to such a constitution, by sending out delay signals theta1-theta5 to each lead wire 5(1-5) connected in common, and controlling a delay time between each delay signal theta, a focal distance F can be varied. When the delay time is made large, the focal distance F becomes long, and when it is made small, the focal distance F becomes short. |
