| 摘要 |
PROBLEM TO BE SOLVED: To accurately measure a distance to a measured object without influence of reflected light from a glass window, a tree branch or the like even when they exist in a space to the measured object. SOLUTION: The ranging device 1 is provided with a laser beam emitter 3 emitting a pulse like laser beam, a reflected light receiver 4 receiving reflected light, and a distance calculator 10 determining a distance from elapsed time until reception of the reflected light. The distance calculator 10 has a counting part 11 counting frequencies when the reflected light satisfies a predetermined condition, a table preparing part 12 preparing a frequency distribution table corresponding to distances by repeatedly emitting the laser beam and integrating the counted frequencies, and a distance determining part 13 determining a portion where a total amount of the frequencies in the frequency distribution table exceeds a predetermined threshold as the distance to the measured object. The threshold is set so it becomes smaller as distance in the frequency distribution table becomes longer.
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