| 摘要 |
PROBLEM TO BE SOLVED: To obtain an optical distance-measuring apparatus capable of measuring a distance with high accuracy and at a high speed even under such a bad condition that the quantity of received light is very weak, that an optical noise at the outside is large or the like, by measuring the coordinates and the quantity of light of the part of an image in a light-irradiated place precisely by using a plurality of photosensors. SOLUTION: Irradiation light 2 whose optical wavelength is, e.g. 670μm and whose modulation cycle of a quantity of light is 1μs is radiated from a laser light source 1. Then, a light-irradiated place 3 is projected, as a real image 6, on a photosensor 5 as a part of a photoelectric conversion means 4. A rectangular quantity-of-light distribution 3A in the light-irradiated place is measured as an output signal corresponding to a quantity of light I composed of I0 10, I0 , I0 /5 in positions of photoelectric- conversion-element pin photodiodes 5a, 5b, 5c. Then, an unwabted noise is removed as an asynchronous noise by an electronic circuit in which light signals received by the respective pin photodiodes 5a, 5b, 5c are synchronized with a frequency having a change in a quantity of irradiated light and which comprises a 1 MHz BPF 8. Consequently, even on a face irradiated with light, which can obtain only very small reflected light or even under an extremely bright environment, a distance can be measured at a high speed and with high accuracy.
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