| 摘要 |
PURPOSE:To reduce production of an error in quantization by a method wherein a gain measuring means to measure the gain of each channel and a correction means are mounted separately away from a measuring means for a delay time, and a delay time is corrected by the correcting means according to a gain measuring result. CONSTITUTION:A delay signal outputted from a delay circuit 1 at each channel is inputted to a sing-around circuit 2 to measure a delay time, and is inputted to a gain measuring circuit 4 to measure a gain. The measured delay time is inputted to a correction circuit 5 togetherwith a gain measuring result, and the correcting circuit 5 corrects the error t of the delay time. As a result, production of an error in quantization is reduced, and a quantization unit can realize 15ns. This constitution enables reduction of a side rope SB in the profile of ultrasonic beam to a low value, and permits improvement of resolution. |
