| 摘要 |
PURPOSE:To facilitate and speed up phase correction by detecting the thickness of the fat layer right under the skin and correcting the delay time. CONSTITUTION:The time tn after plane waves are transmitted by simultaneously driving all elements En before an ultrasonic echo-signal of a prescribed level Vt or above is first received is measured by a time measuring means 20. The measured time indicates the thickness of the fat layer right under the skin. A delay time correcting means 3 corrects at least either of the delay time at the time of transmitting the ultrasonic waves or the delay time before the echo signal is synthesized. The phase correction according to the thickness of the fat layer is executed in such a manner and, therefore, the clear images free from out-of-focus by the phase error is obtd. |
