Abstract: The invention is directed to an arrangement and a method for checking optical diffraction structures (e.g., kinegrams) on documents. The object of the invention, to find a novel possibility for checking optical diffraction structures on documents which permits detection of the presence and authenticity of optical diffraction structures quickly and economically with respect to apparatus, is met according to the invention in that the sensor unit is arranged orthogonally above the support surface of the document, and in that the illumination unit contains at least two monochromatic light sources which are arranged so as to emit light bundles at defined incident angles with respect to a surface normal of the document directed to the diffraction structure and which can be switched on sequentially.

Abstract: The invention is directed to an arrangement and a method for checking optical diffraction structures (e.g., kinegrams) on documents. The object of the invention, to find a novel possibility for checking optical diffraction structures on documents which permits detection of the presence and authenticity of optical diffraction structures quickly and economically with respect to apparatus, is met according to the invention in that the sensor unit is arranged orthogonally above the support surface of the document, and in that the illumination unit contains at least two monochromatic light sources which are arranged so as to emit light bundles at defined incident angles with respect to a surface normal of the document directed to the diffraction structure and which can be switched on sequentially.