| 摘要 |
PROBLEM TO BE SOLVED: To obtain a range-finding device strong in spot chipping in which an active type triangulating range-finding device is weak by providing a means for switching the distribution mode of a photoelectric current to a 1st or a 2nd mode and performing range-finding again in the 2nd mode when the range-finding is performed in the 1st mode and the result of the range-finding is within a specified distance range. SOLUTION: When range-finding is performed in a 1st mode (PSD mode) first and the result of the range-finding is within a specified distance range, the range-finding is performed again in a 2nd mode (SPD mode). Namely, when the result is within the specified distance range being the effective range of the SPD mode, the range- finding is performed in the SPD mode. In this device, a switch of a PSD 5 is turned on to make it in the PSD mode first and an IRED is made to emit light. The light incidence at such a time is detected by the PSD 5, ratio arithmetic operation is performed by a ratio arithmetic operation part 14 of an AFIC 12, and then, range- finding arithmetic operation is performed according to the result. When the obtained result is longer than 1 m and shorter than 5 m, there is the possibility of spot chipping so that the switch is turned off to make it in the SPD mode and the light emission and the ratio arithmetic operation are performed again. |
