1. Apparatus for generating signals for use in aligning with respect to a known reference position an object disposed in the field of view of a television camera on a carrier displaceable in two axial directions, the television camera operable to generate an electrical video signal representative of a video image of a surface of the object and a peripheral area surrounding the object in a line raster frame scan comprising: digitizing means for receiving said video signals and forming therefrom digital video signals of first and second signal levels which for the video signals originating from the object have predominantly said first signal level and for the video signals originating from the peripheral area have said second signal level; analyzing means for (a) analyzing said digital video signals during a plurality of data window sets which are associated with said axial directions and which correspond to regions of the video image which are in a defined position relative to different edges of the video image of the object when the latter is aligned with respect to the reference position, the data windows of each data window set corresponding to parallel video image regions having predetermined distances from each other in the associated axial direction of displacement of the carrier, and (b) furnishing operating signals characterizing the number of data windows present in each set in uninterrupted sequence from the inside to the outside of the video image of the object during which appearance of said digitized video signals having said first level has occurred, said operating signals providing a measure of magnitude and direction of displacement of said object for use in adjusting said carrier to bring said object into alignment with respect to said reference position.