| 摘要 |
<P>PROBLEM TO BE SOLVED: To expand a measurable distance range to both a short distance side and a long distance side while suppressing a prolongation of a measurement period and a manufacturing cost, in a distance measuring device. <P>SOLUTION: In the distance measuring device, power of a composite wave of a transmission wave frequency-swept by a frequency control circuit and a reflected wave is detected, and the detected signal is sampled by an analysis circuit in a specific processing period and a frequency component of the detected signal is analyzed. Then, a distance is calculated on the basis of the analysis result. The frequency control circuit performs sweeps in accordance with each of sweep patterns P1, P2, and P3 different in frequency sweep width from each other. Accordingly, when a distance to an object to be measured is any of short, middle, and long distances, a frequency of the detected signal can be brought within a frequency range analyzable by the analysis circuit, which enables any distance to be measured. Furthermore, in order to expand a measuring range to short/long distance sides, it is unnecessary to prolong the processing period or take, as the analysis circuit, an analysis circuit capable of high-speed operation. <P>COPYRIGHT: (C)2012,JPO&INPIT |
