Patent US 5,696,591

An optical inspection apparatus detects faults in a material coated on a moving web. Multiple cameras are positioned in an array across the width of the web transverse to the direction of the moving web. Each camera comprises a electronic camera and digital signal processor. An illumination source is preferably positioned to illuminate one side of the web. The camera array is positioned on the opposite side of the web aligned with the illumination source. The cameras in the array image the moving web along colas and collect image data from the web. The image is digitized and processed in real-time by averaging each column of image data to produce a profile of light intensity transmitted across the web width from which faults occurring in the longitudinal direction are detected in a host computer.