Distance measuring apparatus

摘要

A distance measuring apparatus measures the time an emitted optical pulse requires to go and return the distance to a target before being received by using the emission time and the reception time of the optical pulse, and obtains the distance to the target from the measured time. A converter converts an optical pulse received by a photodetector into an electrical signal. A divider divides the electrical signal pulse into two signal pulses. A delay element delays only one signal pulse. Both the undelayed and delayed pulses are applied to a threshold generator. The threshold generator generates and holds the value of signal intensity at the intersection of waveforms of the two pulses as a threshold value of the received signal pulse. A comparator generates a digital signal pulse indicating the reception time from the received signal pulse by using the generated threshold value.