To accurately measure time regardless of the strength of reflection laser light and attenuation in the air by generating stop signal respectively when the rise of the first signal of reflection laser pulse exceeds a first threshold and when the rise of the second signal exceeds a threshold of double of the first threshold.
The reflection laser light from a target 13 is transduced into a voltage signal in a receiver 2 and separated into signals 8 and 9 in a separation circuit 10. In a threshold processor 4, a signal 8 rises and exceeds a first threshold and then outputs a stop signal 6 to time measuring devices 7 and 14. As the time of peak of the signal 3 can be determined by adding the time from the rise of the signal to the peak at the moment the signal 8 or 9 start to rise, by calculating the time from the generation of a start signal 5 to the time of peaking of the signal 3 with an operator 22 and the distance to the target can be obtained.
| WO/2021/056666 | TRANSMITTER AND DISTANCE MEASURING SYSTEM |
| WO/2007/028667 | ELECTROOPTICAL MEASURING DEVICE |
NAKAGUCHI TOMOYUKI
KITAMURA YOSHIYUKI
KATOU KIICHIROU
