| 摘要 |
PURPOSE: To conduct envelope detection without deformation or limiting deformation to a minimum of useful signals by composing an envelope detector so that it has a detector connected to a circuit for time signals including the series connection of a dilation circuit and an erosion circuit. CONSTITUTION: The envelope detector 43 is composed of a detector and a low range wave filter in which the detector is connected to a one-dimension structural wave filter circuit 50. The circuit 50 being a closing type circuit, is equipped with a dilation circuit 51 and an erosion circuit 52 to be connected to the dilation circuit 51. The wave filter is applied to form the signal in which morphologic closing would hardly change the shape of demodulated signals when the width of structural elements matches the resolution in the axial direction of the array of an ultrasonic transducer 10. The plane structural element has a tendency to eventually form a considerably broad plateau in signals. |
