Ultrasonic wave diagnostic apparatus with beam convergence and clock

Abstract

A simple, compact and inexpensive ultrasonic wave diagnostic apparatus of electronic focus type in which the delay amount for controlling the phase of a transmission signal for each piezoelectric element is stored in a delay amount storage unit, the pulse width for controlling the frequency of the transmission signal for each piezoelectric element is stored in a pulse width storage unit, the time elapsed from a reference time point is counted by a counter, a change point of the transmission signal from the reference time point is calculated by a processor, the output of the processor is compared with the output of the counter by a comparator, a plurality of clock signals having different phases are generated by a multiphase clock generator, a clock generated by the multiphase clock signal generator is selected by a selective controller, and a pulse of the transmission signal is generated on the basis of the selected clock by a toggle circuit. The delay amount, the duty factor and the frequency of the transmission signal are controlled for each piezoelectric element to converge the ultrasonic wave beam, thereby making possible a highly accurate diagnosis with high image quality.