Method for detecting objects located on a transparent panel, and corresponding device

摘要

The invention relates to a method for detecting objects which are located on a transparent panel and which produce light reflexes when illuminated, using a detector unit containing one or more optical sensor arrays. The inventive method comprises the following steps: illuminating the panel in order to produce light reflexes in or on the objects which are located on the panel, from the side of the panel behind which the detector unit is located; image detection of an illuminated section of the panel using the detector unit by preparing two panel section images which together form an image pair, the light reflexes(es) of an object located on the transparent panel produced through illumination being located at differently-positioned image points in each of said panel section images; determining the differential image of the two images of an image pair by subtracting the contents of identically positioned image points of one panel section image from those of the other panel section image and evaluating the differential image determined in terms of the contents corresponding to the individual image points.