| 摘要 |
PURPOSE:To prevent an undersirable influence caused by a noise by controlling a grounding switch circuit so as to ground a connecting part of a vibrator and a high voltage analog switch circuit before the high voltage analog switch is switched, and also, it is detached after the switching. CONSTITUTION:A control circuit 1 outputs a data signal 2 for a grounding analog switch 4 before a driving signal is outputted from a transmitting circuit S, latches it by a latch signal 3, and grounds a connecting part of each vibrator E1, E2,... and a high voltage analog switch SW. Subsequently, the data signal 2 for SW, and a latch signal 53 are outputted, and an internal switch is switched so as to select a prescribed vibrator. In this case, a noise alpha is generated from SW, but it is not applied to the vibrators E1, E2,.... Next, the data signal 2 for turning off all the internal switches of the grounding analog switch 4 is outputted, and it is latched by the latch signal 3. In such a way, the vibrator is driven by a driving signal from the transmitting circuit S, and also, an ultrasonic echo signal can be inputted to a receiving circuit R. |
