| 摘要 |
PURPOSE:To perform the positioning of a line sensor with respect to a beam cut image with good accuracy, by detecting the separate height regions of the beam cut image by one line sensor. CONSTITUTION:When an object M to be detected is irradiated with sheet like beam L1 by a beam irradiation means 11, a beam cut line (l) is formed to said object M along the uneven shape by a pattern P. The reflected beam L2 therefrom is split into two split beams L3, L4 by a beam detecting means 12 and the respective beams become beam cut images m1, m2 parallelly shifted in a height direction to be formed into images on the separate regions 125a, 125b of a line sensor 125. That is, two height regions different from each other of the beam cut images m1, m2 are detected by one line sensor 125. The detection signals obtained in the separate regions of one line sensor by this method are sent to a signal processing means and, on the basis of the intensity difference between said signals, the presence of the pattern P can be discriminated. |
