| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce measurable distance resolution without increasing an operation clock frequency in a distance measuring apparatus of a spread spectrum system. SOLUTION: A laser light modulated by the maximum period sequence code is outputted from a transmitting part 14, and its reflected light is received and demodulated by a receiving part 16-a comparator 20. A correlation value between the demodulated code and the maximum period sequence code is calculated by a matched filter 22. A time when the correlation value becomes maximum is detected by a peak detector 24, and time data D1 are obtained. By transmission and reception of a single pulse signal, measurement error (time data D2) of the time data D1 is measured. From D1 and D2, a distance as far an object is calculated. A transmission pulse signal is delayed by a delay part 40 with a delay time corresponding to the time data D1, and phase difference between the transmission pulse signal after delaying and the receiving pulse signal is obtained by an A/D converter part 50 wherein the time resolution is shorter than the period of a reference clock, thereby obtaining the time data D2.</p> |
