| 摘要 |
PROBLEM TO BE SOLVED: To provide different speckle patterns for different scanning lines that are in proximity to one another as to time or space to smooth the speckle patterns on an ultrasonic image by transmitting or receiving ultrasonic waves of different frequencies. SOLUTION: Frequencies f1 , f2 are transmitted and received for an odd- numbered scanning line 44 and an even-numbered scanning line 46, respectively, on the sectored scanning surface 40 of an odd-numbered frame. The frequencies f2 , f1 are transmitted and received for an odd-numbered scanning line 48 and an even-numbered scanning line 50, respectively, on the sectored scanning surface 42 of an even-numbered frame. Therefore, interference requirements for reflected waves differ among the scanning lines and the frames, resulting in the dispersion of speckle patterns. Similar effects can also be obtained by transmitting uniform, wide bands of frequencies for each scanning line, and filtering the bands that differ among the scanning lines and the like using a filter during reception, and processing them into an image. |
