DISTANCE MEASURING DEVICE

摘要

A distance measuring device measures a distance from a phase difference of beaten down processing signals even when fluctuations occur in a frequency of an oscillator. The distance measuring device includes a laser unit 1 for generating an optical frequency comb as a laser light flux, a reference light receiving unit 3 for receiving reference light 27, and a measuring light receiving unit for receiving distance measuring light 28. A first mixer 31 and a second mixer 32 multiply received light signals of the measuring light receiving unit 6 and the reference light receiving unit 3 by a periodic signal of the oscillator 50. The periodic signal has a specific frequency. A fourth filter 51 and a fifth filter 52 extract frequency components which are different, from signal components generated by the first mixer 31 and the second mixer 32. The signals extracted by the fourth filter 51 and the fifth filter 52 are multiplied with each other by a third mixer. A difference frequency component is extracted by a sixth filter 54. A phase difference measuring unit 12 measures a phase difference of two processing signals from the sixth filter 54 and the second filter 11. A distance measuring unit 17 measures a distance based on the phase difference.