Abstract: The invention relates to a method of generating a laser marking in a security document by means of at least one laser beam, the security document having at least one laser-markable layer and also at least one reflecting layer which overlaps at least partly with the at least one laser-markable layer and has opaque regions. The at least one reflecting layer has at least one transparent region and, at least visually, is not significantly altered by the laser treatment of the laser-markable layer.

Abstract: The invention relates to a method of generating a laser marking in a security document by means of at least one laser beam, the security document having at least one laser-markable layer and also at least one reflecting layer which overlaps at least partly with the at least one laser-markable layer and has opaque regions. The at least one reflecting layer has at least one transparent region and, at least visually, is not significantly altered by the laser treatment of the laser-markable layer.

Abstract: The arrangement comprises a tracking sensor with a light source, an optical means and a receiver with two photosensitive detectors, as well as a measuring apparatus with a computing unit. The optical means focuses light to provide a beam which falls on a moving web of foil. The tracking sensor may, for example, be installed in a re-winding installation, and during re-winding of the web, senses by means of the beam a marking track which is embossed in the web in the longitudinal direction of the web and which is composed of two different diffraction grating tracks. Each diffraction grating track projects the light diffracted therefrom in a predetermined direction of incidence to a respective detector. The sensed signals supplied by the receiver are converted into a difference signal by the measuring apparatus, and processed to provide correction signals which are supplied to a control means of the re-winding installation in order to compensate for lateral deviation of the moving web of foil.