Title:
【発明の名称】超音波パルスの受信波到達検出回路
Document Type and Number:
Japanese Patent JP2656396
Kind Code:
B2
Abstract:
PURPOSE:To detect the received time of an ultrasonic wave pulse accurately. CONSTITUTION:Either of a peak holding circuit 7 or 8 in two systems detects the peak value of a received signal. Every time the received signal crosses a zero level twice, the peak value which is detected with one peak holding circuit described above is held. At the same time, the other peak holding circuit detects the peak value of the following received signal. This operation is repeated. The fact that the peak value which is detected with one peak holding circuit exceeds a reference voltage and becomes the value which is several times or more of the peak value that is held by the other peak holding circuit, i.e., the existence of a trigger wave, is detected with trigger-wave detecting circuits 9, 10 and 11. When the received signal crosses the zero level after the trigger-wave detecting circuits detect the trigger wave, a detecting circuit 15 detects the arrival of the received signal.
Inventors:
ISHIHARA TAKASHI
Application Number:
JP10350491A
Publication Date:
September 24, 1997
Filing Date:
April 10, 1991
Export Citation:
Assignee:
KAIJOO KK
International Classes:
G01S7/526; G01S11/14; G01F1/66; (IPC1-7): G01S11/14; G01F1/66; G01S7/526
Domestic Patent References:
| JP56148016A | ||||
| JP58120119A | ||||
| JP3122586A | ||||
| JP4177192A | ||||
| JP6336474B2 |
Attorney, Agent or Firm:
Wakabayashi Tadashi