METHOD AND DEVICE FOR THE DETECTION OF A SUBSTRATE EDGE IN A PRINTING MACHINE

摘要

The present invention relates to a method and a device for the detection of a substrate edge in a printing machine comprising a substrate transport unit that defines a substrate transport path (8). In this method, at least one light value of a first section of a sensor line (10) and a dark value of a second section of the sensor line are determined, and a threshold value is calculated based thereon. When the threshold value on one pixel is exceeded and the threshold value on another pixel is not reached, it is possible to calculate a position of the substrate edge. The device comprises a light source arrangement (5) for generating diffuse light, and comprises a sensor line for the detection of light from the light source arrangement. Furthermore, a gradient lens arrangement (15) is provided, said gradient lens arrangement being arranged between the light source and the sensor line in such a manner that, on the one hand, a focus is located on a central position of the substrate transport path between the light source and the gradient lens arrangement, and, on the other hand, on the sensor line.