OPTICAL DISTANCE MEASURING DEVICE

An optical distance measuring device (10, 11) includes a light emitting part (21), a mirror (26) that reflects the illumination light (IL) emitted by the light emitting part, a scanner (28) that scans a predetermined scanning range with the irradiation light by operating the mirror in a forward movement motion and a backward movement motion, a light receiving part (30) that detects a reflected light returned by reflecting the irradiation light from a target existing in the scanning range, a distance calculating part (40) that calculates a distance to the target using a time from an emission of an irradiation light by the light emitting part to the detection of the reflected light from the target by the light receiving part during the forward movement motion of the mirror, a timing signal generating part (60) that generates the timing signal according to a signal from an outside of the optical distance measuring device, and a control unit (50, 51) that controls a light emission of the light emitting part and an operation of the scanner. The control unit (50) synchronizes the operation of the scanner with a predetermined timing signal by adjusting a time of one cycle of the scanner while maintaining the distance measuring period of the forward movement motion of the mirror.