| 摘要 |
<p>PURPOSE:To make the potential warp of a plate appear in a line thereby to detect the warp with high accuracy and to feedback to the actual operation by casting a laser light on a plate to be inspected slantwise at an angle of 20 deg. or less in a widthwise direction of the plate. CONSTITUTION:A laser projector 6 casts a laser light on a fed plate to be inspected 1 slantwise at an angle of 20 deg. or less in a widthwise direction of the plate. An image processor operates the warp of the plate in the widthwise direction from a laser reflecting image on a screen 7 photographed by 8. When a laser is cast by 6, a reflecting image of the laser light indicates a curve corresponding to the warp. The curve of the reflecting image is proportional to the amount of the warp L. In other words, supposing that a distance of a ridge of the curve from a straight line connecting points crossed by the laser lights at both edges of the plate 1 is A, A=L/sintheta1 is held. Therefore, if theta1 is set not larger than 20 deg., A can be obtained large. In this manner, a minute warp can be detected with high accuracy on line, and fed back or fed forward to the actual operation.</p> |
