| 摘要 |
PURPOSE:To deflect an ultrasonic wave by obtaining a large delay time and to attain a low cost without requiring a delay circuit or delay line by which large delay time can be obtained. CONSTITUTION:This system is equipped with two independent delay circuits 7A, 7B which supply delay to a received echo signal, a first switch 4 which switches the output of the delay circuits 7A, 7B alternately or to either one, and a second switch 15 which connects the delay circuits 7A, 7B in series. The output of the two delay circuits 7A, 7B are switched alternately at every desired focusing zone by the first switch 4 in a B mode. When an ultrasonic beam is deflected, the large delay time can be obtained by connecting the two delay circuits 7A, 7B in series by the second switch 15, and selecting the output of either the delay circuit 7A or 7B connected in series by the first switch 4. |
