Method and apparatus for inspecting a web of material for defects, using the method in preparing a magazine reel in a reel changer, and reel changer provided with such an apparatus

摘要

A method of inspecting a web of material for defects involves light being emitted from one side of the web of material, observing the surface thus illuminated, and analysing the observed image for defects. In a preferred method, the light is alternately emitted in two directions at an acute angle with respect to the plane of the web of material, and the illuminated surface is observed from the same side as the illumination, for example with the aid of a CCD camera.