| 摘要 |
<p>Disclosed is an optical distance measurement device provided with: a first light projecting unit (1) which projects, to a subject to be measured, a measurement light signal being subject to high frequency modulation at a predetermined frequency; a second light projecting unit (2) which projects a reference light signal being subject to high frequency modulation at a frequency minutely different from the frequency through a light path inside the device; a light receiving unit (3) which has a single light receiving circuit (31) that outputs a beat signal obtained by receiving and mixing both the measurement light signal projected from the first light projecting unit (1) to be reflected by the subject to be measured and the reference light signal projected from the second light projecting unit (2) and a light receiving signal amplifying circuit (32) that amplifies the beat signal; a synchronous detection circuit (5) which synchronously detects the beat signal from the light receiving unit (3) to obtain synchronously detected output; and a phase consistent point extracting circuit (7) which extracts a phase consistent point of the beat signal from the synchronously detected output to obtain phase shift of the measurement light signal and the reference light signal, wherein a distance to the subject to be measured is measured on the basis of the phase shift.</p> |
