Patent ID: 8282556

Claim:
An ultrasonic diagnostic apparatus comprising: a plurality of ultrasonic transducers for transmitting ultrasonic waves according to drive signals and receiving ultrasonic echoes to output reception signals; signal processing units each performing one of quadrature detection processing and quadrature sampling processing on a reception signal outputted from respective one of said plurality of ultrasonic transducers to generate a complex baseband signal; first computing units each obtaining an amplitude value signal representing an amplitude value of the complex baseband signal and a phase value signal representing a phase value of the complex baseband signal generated respective one of by said signal processing means units, the amplitude value signal and the phase value signal having a predetermined sampling interval; a phase correction value table for storing phase correction values to be used for correcting the phase value for a time difference according to relative positions of a reception focus and said plurality of ultrasonic transducers, the phase correction values including at least one phase correction value to be used for correcting the phase value for the time difference finer than the predetermined sampling interval; a phase correcting unit for reading out a phase correction value from said phase correction value table according to a reception direction and correcting the phase value obtained by each of said first computing units by using the phase correction value; second computing units each obtaining a real number component and an imaginary number component of a corrected complex baseband signal represented by the amplitude value obtained by respective one of said first computing units and the phase value corrected by said phase correcting unit; and an adding unit for adding real number components of corrected complex baseband signals obtained with respect to said plurality of ultrasonic transducers by said second computing units to one another to generate a phase-matched and added real number signal, and adding imaginary number components of the corrected complex baseband signals obtained with respect to said plurality of ultrasonic transducers by said second computing units to one another to generate a phase-matched and added imaginary number signal.