| 摘要 |
PURPOSE:To improve the accuracy in measurement of short distances by controlling the output signal of a variable output means in such a way that the results of integration integrated during the time of a time difference between a transmitted wave and a received wave attain a predetermined specified value and obtaining the distance to be measured in accordance with the results thereof. CONSTITUTION:The output signal of an integrating circuit 13 is supplied to a sample holding circuit 20, and further the difference between the voltage supplied with a differential amplifier 21 and the reference voltage connected to a non- inversion terminal is detected and amplified. The output signal thereof is supplied to the inversion input terminal of an operational amplifier 22. The output voltage V4 of the amplifier 22 is supplied to a switch element 11 and a dividing circuit 23. |
