| 摘要 |
PURPOSE: To reduce phase aberration in an image by correcting the delay time used in the formation of image forming exciting beam and the delay time of a return signal received from a medium to be examined on the basis of the time correction quantity to a converter. CONSTITUTION: A converter arrangement 11 has a plurality of converters..., 11(K-l),11K, 11(K+l)... and front end parts... 16(K-1) are arranged to the respective converters. The phase correction times to respective channels are substantially generated by propagation errors by ADC means 64a, 64b, a digital base band demodulation means 66, low-band filter means 68a, 68b, receiving means 70a, 70b, channel delay means 72a, 72b, a delay control means 46, a phase slip memory means 44 and a clock control means 60. A phase conjugated processing means is connected to front end means... 16(K-1).... |
