| 摘要 |
PROBLEM TO BE SOLVED: To achieve a higher distance measuring accuracy by a method wherein a photodetector receives projection light reflected on an object to generate two outputs according to a distance to the object and the two outputs are amplified, integrated and counted to calculate the distance to the object. SOLUTION: A photodetecting means 3 receives irradiation light of a projection means 21 reflected on an object and outputs two currents. Then, the two currents are converted by current/voltage conversion circuits 30 and 40 to respective voltages and the results are integrated by an integration circuit 70 via amplification circuits 50 and 60. Two outputs corresponding to the currents of the integration circuit 70 are counted by a counting means as values N1 and N2. The counted results, C1 and C2 are defined as constants and P1 and P2 as constants of 0 or 1 or more to calculate the distance to an object by an arithmetic means 11 based on a value X given by X=N1×(C1/N1)P<2> / N1×(C 1/N1)P<2> +N2×(N2/C2)P<1> }. |
