METHOD AND DEVICE FOR MEASURING THE POSITION OF THE EDGE OF A MATERIAL WEB

摘要

A device and method provide for measuring the position of the edge of a material web by illuminating an area of the edge area and detecting shadows cast by the material web. Two or more transmitters arranged in a line transverse to the edge of the material web are used for illumination. A linear sensor also arranged transverse to the edge of the material web is used to sense the locations of the shadows. The position of the edge of the material web is detected from the sensed shadow and the locations of the transmitters and sensors.