METHOD FOR DETECTING BUILD UP OF ACOUSTIC WAVE SIGNAL

摘要

PROBLEM TO BE SOLVED: To easily detect the rise of an acoustic wave signal while discriminating from noise in a method for detecting the build up of the acoustic wave signal received by an ultrasonic element element. SOLUTION: When the acoustic wave signal is received by the ultrasonic receiving element, the acoustic signal is stored in time series. A window W having a predetermined time band to the stored signal is scanned in the time axial direction (arrowed direction a) based on the transmitting time t0 of sound wave at a window width pitch, and the integrated value of waveform 10 of the acoustic signal in the window W is computed for each of scanning positions W1 and W2. It is determined whether or not the resulting integrated value is more than threshold. When the integrated value is the threshold or more, the time t' corresponding to the window position W2 at the time when the window W is detected is taken as the rise timing. COPYRIGHT: (C)2005,JPO&NCIPI