| 摘要 |
PROBLEM TO BE SOLVED: To prevent erroneous distance measurement from generating even if a positive reflecting object exists on a light projected position by comparing the size of an actual light receiving image on a light receiving means with the size of an ideal light receiving image. SOLUTION: Light projecting signals of IRED(light projecting means) 103 + external light and external light are accumulated by the use of the ring CCD of a light receiving device 105, and when the accumulating operation is completed, a CPU 101 searches for the gravity center position and the size (width) of a light receiving image on sensor array (light receiving means). By a comparison means provided in the CPU 101, the size of an actual light receiving image on the sensor array is compared with the size of an ideal light receiving image decided corresponding to the gravity center position of the actual light receiving image, and it is judged whether the actual light receiving image contains an error or not. Hereby, because existence of a positive reflected image due to a positive reflecting object can be judged and excluded, dislocation of the center of gravity of the whole is eliminated, and because signals from a distance measuring object can be accumulated regardless of a positive reflecting image, S/N can be improved. |
