Device for selecting originals not worth copying in a photographic printer

摘要

Contained in the photographic printer is a device for selecting originals not worth copying, which are combined in accordance with a multiplicity of jobs to form a long strip. Provided on the strip are marks which characterise the position of the images and the beginning of the originals belonging to a job. Moreover, a film splice scanner (16), a notch scanner (17) of the original strip (1) and a quality detection scanning unit (18) are arranged on the transport path of the original strip (1) upstream of the copying station (4). The quality detection scanning unit (18) can be switched on and off by a selection logic (20) or be switched over to response thresholds of different sensitivity, specifically either on the basis of a pulse from the film splice scanner (16) or of a pulse from a counter (19), inserted between the notch scanner (17) and the selection logic (20), after a settable number of image marks before or after a job end mark, or of the detection of a first image worth copying inside a job. It is thereby achieved that the pictures for no-load switching are reliably detected at the start of a film, whereas the selection device is ineffective in the main part of the film or has an insensitive response threshold. IMAGE