Patent ID: 8773533

Claim:
A detection system comprising: an image capturing unit which captures an image; a light source which has a luminance which changes by a period of a predetermined multiple of a scanning plane period of the image capturing unit; a pre-processing unit which acquires an output signal at the time when the image capturing unit captures the light source or object for each predetermined scanning plane period, calculates a first time-average value of the output signal level difference between the m (m=1, 2, . . . )th and (m+2)th scanning planes, and calculates a second time-average value of the output signal level difference between the (m+1)th and (m+3)th scanning planes; a post-processing unit which executes processing which uses the first time-average value and the second time-average value calculated by the pre-processing unit as the basis to detect the state of the light source or the object; a detection unit which detects the state of the light source or the object in accordance with the processing value of the post-processing unit; and a correction instruction unit which outputs a correction instruction signal in a case where an absolute value of either of the first time-average value and the second time-average value of the pre-processing unit exceeds an allowable drop, wherein the post-processing unit corrects the time-average value of the time-average value which drops in absolute value until the drop becomes the allowable drop or less when receiving the correction instruction signal of the correction instruction unit and then executes the above processing.