LIGHT WAVE RANGE FINDING DEVICE AND OPTICAL PATH SWITCHING METHOD IN LIGHT WAVE RANGE FINDING DEVICE

摘要

PURPOSE: To shorten processing time by continuously detecting a phase difference between the emitting light and the measuring light selected by a switched optical path or the reference light twice every time when optical paths are switched. ;CONSTITUTION: An optical path switching part 4 alternately switches the emitting light of a light sending block 3 to a light sending optical system 5 and an inside reference light block 9. The measuring light passing through the optical system 5 is reflected by the measuring point side reflected light 200, and enters a light receiving block 8 through a light receiving optical system 6. The block 9 introduces the reference light to the block 8 from the block 3, and it is photoelectrically detected by the block 8. A received signal is beated down by a mixer 11, and an opening-closing signal according to a phase difference is generated by a gate circuit part 13 together with a comparing reference signal of a respective frequency signal generator 2, and is counted by a counting circuit part 14, and a distance value is found by a control operation part 12. At this time, since procedding is controlled by the operation part 12 so as to continuously detect a phase difference twice by a switched circuit every time a switching part 4 switches optical paths, the number of switching times is reduced as a whole, and processing speed is increased.;COPYRIGHT: (C)1996,JPO