| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To determine accurate reception timing at all times regardless of the type of measuring medium or the strength of reception levels. <P>SOLUTION: A reception signal is converted into a staircase wave via a peak hold circuit, and output of the peak hold circuit is supplied to one input terminal of a comparison circuit as it is. The output of the peak hold circuit is supplied to the other input terminal of the comparison circuit via a waveform shaping circuit for converting the output of the peak hold circuit into an integral waveform synchronous with its voltage. Based on the output of the comparison circuit, the time difference between a transmission signal and the reception signal is computed. The reception signal may be a direct wave or a reflected wave. Signal medium may be any one of an ultrasonic wave, a radio wave, or infrared light. <P>COPYRIGHT: (C)2004,JPO</p> |
