| 摘要 |
PURPOSE:To simultaneously form received wave beams in plural directions to many ultrasonic received wave signals even if a low speed A/D converter is used. CONSTITUTION:As a digital delay means 4' for arbitrarily delaying a digital signal input from an A/D converter 3 and outputting plural delay signals, a first delay circuit 11 for delaying a digital signal from the A/D converter 3 at intervals of a sampling cycle and an interpolation delaying circuit 12 for delaying output signals input from the first delay circuit 11 at intervals shorter than the cycle of the sampling cycle and outputting plural delay signals are combined. Thus, the sampling period of the A/D converter 3 in the preceding stage of the digital delay means 4 may be late, and even if the low speed A/D converter 3 is used, received wave beams can be simultaneously formed in plural directions. |
