Patent ID: 7154079

Claim:
A moving object detecting system for detecting a moving object in a passage, comprising: a light projecting device which irradiates a slit light beam to a line as a subject to be irradiated along a widthwise direction of the passage; a imaging device which image-captures an area including the line to obtain an image; a producing portion which produces, from the image, line data of one-dimensional arrangement of point data corresponding to each position on the line; a judging portion which judges whether the slit light beam is blocked or non-blocked at each position on the line based upon the line data; and a detecting portion which detects the moving object based upon the result of the judgment by the judging portion, wherein, when a direction corresponding to the widthwise direction is defined as a first direction and a direction perpendicular to the first direction is defined as a second direction in the image and the line data, a value of an evaluation function taking each pixel value of a pixel array in the image arranged in the second direction as an argument is rendered by the producing portion to be a value of point data in the line data having the same position as that of the pixel array in the first direction, the evaluation function value depending upon the result of the difference between the pixel values of adjacent pixels in the pixel array.