Ultrasonic imaging apparatus

摘要

A phase adjustment circuit for use in an ultrasonic apparatus which respectively time-adjusts a plurality of received signals from an ultrasonic transducer array and sets wave fronts of the reflected waves from particular positions into an in-phase state and adds the in-phase signals, thereby obtaining a received beam. The received signals are mixed with phase-controlled reference signals. The low frequency component of the mixed wave is sequentially sampled and stored in a memory which is controlled by a clock signal of a predetermined period, and thereafter, the stored sampled signals are read out. Most of the necessary time adjustment results from the difference between the writing time and the reading time. The remaining micro time adjustment is performed by phase control of the reference signals.