Patent ID: 8043220

Claim:
An ultrasound diagnostic apparatus comprising: an ultrasound probe; a transmission unit for transmitting an ultrasound signal to an object to be examined via the ultrasound probe; a reception unit for processing a signal received by the ultrasound probe; and an image generating unit for generating a tissue harmonic image on the basis of the received signal processed by the reception unit, the transmission unit being configured to transmit an ultrasound signal including a first waveform and an ultrasound signal including a second waveform formed by time-inverting the first waveform, having varying frequency plural times in an identical direction at time intervals, and the reception unit being configured for phasing and adding the received signals respectively corresponding to the first waveform in which the frequency to increase and the second waveform in which the frequency to decrease, wherein: the transmission unit has a function of varying the first waveform so that the frequency sequentially increases and varying the second waveform so that the frequency sequentially decreases, the transmission unit being configured to variably set a transmission focus depth of the ultrasound signal, and a difference (Δf) between a frequency (f 1 ) in a first cycle and a frequency (f 2 ) in a second cycle, and a ratio (A 2 /A 1 ) between an amplitude (A 1 ) in the first cycle and an amplitude (A 2 ) in the second cycle are variably set in response to a predetermined transmission focus depth.