An ultrasonic imaging device includes an ultrasonic probe with a plurality of vibrators arranged linearly for transmitting ultrasonic beams to an object and receiving the reflected ultrasonic beams from the object. A driving unit is constructed to control the plurality of vibrators using a time control which employs delay lines to transmit ultrasonic beams to the object in a convergent manner and to receive diverging ultrasonic beams from the object. The ultrasonic imaging device further includes a processing unit for processing the signals from the probe to obtain the reconstruction data and a display unit for displaying the reconstruction data. Since the ultrasonic beams are transmitted using the plurality of vibrators, the transmitted ultrasonic beams are strong; therefore improving the SN ratio.