| 摘要 |
PURPOSE:To remove noise light mixed into a light receiving device effectively, by taking out the difference between the output of the light receiving device when a light beam is received and the output of the light receiving part when only the noise light is present during the time the light beam is not present. CONSTITUTION:Before the distance measuring beam is projected from a light beam projecting means 8, the noise light received by the light receiving part 10 is transduced into an electricity by the light receiving part 10, and stored in a memory device 11, which sends out an output signal SN. Then, the distance measuring light beam projected by the light beam projecting means 8 is reflected by an object 9, and inputted into the light receiving part 10. Then a distance signal S is outputted. In a subtractor 12, the difference S-SN between said two signals is taken, and the correct distance signal SL is outputted. In an operator 13, the distance to the object is computed based on the correct distance signal SL. |
