Distance measuring device

A distance measuring device comprising:

• a light emitting unit configured to emit pulsed signal light;
• a light receiving array unit including a plurality of photodetectors, each of which is configured to output a pulse signal in response to incidence of a photon;
• a signal intensity calculation unit configured to calculate a signal intensity that indicates a light intensity of the signal light received by the light receiving array unit;
• a signal time calculation unit configured to calculate a rise time and a fall time of the signal light detected by the light receiving array unit;
• an intensity correction unit configured to correct at least one of the rise time and the fall time calculated by the signal time calculation unit based on the signal intensity calculated by the signal intensity calculation unit;
• a distance calculation unit configured to, in response to the rise time being corrected, calculate an object distance that is a distance to an object that reflected the signal light, based on at least the corrected rise time, and in response to the fall time being corrected, calculate the object distance based on at least the corrected fall time;
• a pulse width calculation unit configured to calculate a pulse width of the signal light based on the corrected rise time and the corrected fall time;
• and
• a pulse width determination unit configured to determine whether the pulse width calculated by the pulse width calculation unit is greater than or equal to a preset calculation criterion value, wherein
• the distance calculation unit is configured to switch between a plurality of methods of calculating the object distance according to a result of determination by the pulse width determination unit.