To prevent erroneous detection of received wave signals as precisely as possible even in cases of piezo-electric ultrasonic-generating elements having a property of received wave signals of initial lower rising and subsequent gradual growth.
A first, a second and a third sensors S1, S2a and S3a are respectively linearly arranged along the right and left directions and a vertical direction perpendicular thereto on a substrate 1 of an array sensor 2, and when a wavelength of ultrasonic wave generated from an acoustic source is , the second sensor S2a is disposed at a space L of less than /2 from the first sensor S1 and the third sensor S3a is disposed at a space of n (n: a natural number) from the first sensor S1. A control section 3 runs a prediction means obtaining a predicted value of a wave receiving time of the third sensor S3a by multiplying a difference of wave receiving times between the second sensor S2a and the first sensor S1 by n/L and a confirmation means employing only the received wave signals detected within a predetermined period from the predicted value in the third sensor S3a as correct signals.
NISHIMURA MICHIO
MITSUI TOSHIO
MAKI KEI
NOHARA YASUHARU
| JPH04295786A | 1992-10-20 | |||
| JP2000506971A | 2000-06-06 | |||
| JP2007085866A | 2007-04-05 | |||
| JP2007333656A | 2007-12-27 | |||
| JP2008180593A | 2008-08-07 | |||
| JP2008070161A | 2008-03-27 | |||
| JP2005051688A | 2005-02-24 | |||
| JPH04295786A | 1992-10-20 | |||
| JP2000506971A | 2000-06-06 |
Yoshinori Iwahara
Susumu Yamamoto