Distance measuring apparatus and distance image photographing apparatus

A distance measuring apparatus comprising:

• an irradiator that emits an irradiation wave to a measuring target;
• a first detector that directly detects the irradiation wave;
• a second detector that detects a reflection wave, the reflection wave being the irradiation wave reflected by the measuring target;
• a simulation signal generator that generates a simulation signal, the simulation signal being simulated waveforms of output signals of the first detector and the second detector;
• a first meter that measures a time at which the simulation signal is received to obtain a first time, and that measures a time at which an output signal from the first detector is received to obtain an emission time of the irradiation wave;
• a second meter that measures a time at which the simulation signal is received to obtain a second time, and that measures a time at which an output signal from the second detector is received to obtain an incidence time of the reflection wave;
• a first subtractor that subtracts the emission time from the incidence time to obtain a measurement time period, and that subtracts the first time from the second time to obtain an error time period, the measurement time period being regarded a distance between the irradiator and the measuring target, the error time period being a difference between a delay time of the first meter and a delay time of the second meter;
• and
• a second subtractor that subtracts the error time period from the measurement time period to obtain an offset measurement time period, the offset measurement time period being the measurement time period corrected for the error time period.