Optical distance measuring device

An optical distance measuring device, comprising:

• a light emitting part;
• a mirror configured to reflect an irradiation light emitted by the light emitting part;
• a scanner configured to cyclically perform an operation of scanning 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 configured to detect a reflected light returned by reflecting the irradiation light from a target existing in the scanning range;
• a distance calculating part configured to calculate a distance to the target during the forward movement motion of the mirror using a time from an emission of an irradiation light by the light emitting part to a detection of the reflected light from the target by the light receiving part;
• and
• a control unit configured to control a light emission of the light emitting part and an operation of the scanner, wherein
• the control unit synchronizes the operation of the scanner with a predetermined timing signal by adjusting a time length of one cycle of the scanner while maintaining, in the time length of the one cycle, a distance measuring period which is a period for measuring the distance to the target and which is also a period of the forward movement motion of the mirror.