ULTRASONIC DIAGNOSTIC APPARATUS

摘要

PURPOSE:To provide a transducing circuit of an ultrasonic diagnostic apparatus which stabilizes a DC bias of a are-amplifier of a receiving circuit immediately after the transmission to amplify a received signal normally immediately after the transmission from a specimen. CONSTITUTION:An receiving analog switch 4 is provided between a driver circuit 1 and a pre-amplifier 5 to cut the receiving analog switch 4 only for a specified time at the time of transmission and immediately after the transmission. The cutting of the receiving analog switch 4 reduces effect of the capacitance of a transmitted pulse. Thus, changes in DC bias of the pre-amplifier 5 becomes limited thereby enabling the receiving of a close range signal with the shortening of saturation time.