ULTRASONIC TRANSDUCER DRIVING CIRCUIT AND ULTRASONIC IMAGE DISPLAY APPARATUS

摘要

An ultrasonic transducer driving circuit configured to supply an output current and/or an output voltage to an output line for driving an ultrasonic transducer is provided. The ultrasonic transducer driving circuit includes a first current discharge circuit configured to allow a current arising from electric charges accumulated in the ultrasonic transducer to flow from the output line to ground when the output line is at a positive voltage, and a second current discharge circuit configured to allow the current arising from the electric charges accumulated in the ultrasonic transducer to flow from ground to the output line when the output line is at a negative voltage. The first current discharge circuit and the second current discharge circuit are controlled based on the output current and/or the output voltage.

主权项

1. An ultrasonic transducer driving circuit comprising:
a voltage output type circuit configured to control an output voltage and to supply an electrical current to an output line for driving an ultrasonic transducer; and a buffer amplifier along an output line of said voltage output type circuit, the buffer amplifier configured to receive an output voltage of said voltage output type circuit, said buffer amplifier comprising: a first push-pull circuit of comprising a first transistor and a second transistor connected to an output line of the buffer amplifier; and a second push-pull circuit comprising a third transistor and a fourth transistor connected between the output line of said buffer amplifier and a ground, wherein each transistor of said first push-pull circuit and said second push-pull circuit is configured to receive a voltage having a predetermined voltage difference relative to the output voltage of said voltage output type circuit; wherein the predetermined voltage difference is larger for said fourth transistor than for said second transistor, such that said fourth transistor has an ON state based on the output voltage of said voltage output type circuit when the output line of said buffer amplifier is at a positive voltage to allow a current arising from electric charges accumulated in the ultrasonic transducer to flow from the output line of said buffer amplifier to the ground; and the predetermined voltage difference is larger for said third transistor than for said first transistor such that said third transistor has an ON state based on the output voltage of said voltage output type circuit when the output line of said buffer amplifier is at a negative voltage to allow the current arising from the electric charges accumulated in the ultrasonic transducer to flow from the ground to the output line of said buffer amplifier.