Detecting the optical displacement over various surfaces

Embodiments of the present invention allow an optical device to track on a diffusing surface over which a transparent and / or translucent and / or optically smooth surface is placed. Some embodiments are Dzau designed to detect it when an optical device is lifted from the surface on which it rested before. Embodiments auserden comprise a detection system which detects the z-distance (distance to the tracking area) and the image quality improved by making the effectiveness of the optical sensor subsystem and / or the illumination subsystem is improved when the detected z-distance. Other embodiments include a system and method that allow an optical device tracking on a transparent and / or translucent and / or optically smooth surface alone. This can (dirt z. B.) which are already present on the transparent surface include a dark field image, based on certain features. Alternatively, this may include generating of features such as droplets, the distribution of contaminant residues and the generation of thermal points which can be used for tracking.