Abstract: A sensor is proposed for authenticity identification of luminescent identification features on documents, in which the identification feature is illuminated with an excitation wavelength and may respond at a different wavelength, with the response wavelength being detected and evaluated by a radiation receiver. The focused beam emitted from a beam source is converted by focusing optics in such a manner that a scanning line, which is approximately in the form of a bar, is projected on the surface of the document to be investigated, which causes the signet, which is arranged on the document, to fluoresce at least in one subregion, and the fluorescence signal produced in this way is passed via detection objects to an evaluation unit, which evaluates the fluorescence signal.