Punch alarm system for photoprinting machines

摘要

Sensors are added to a conventional photoprinting machine, adjacent the edges of the photographic print paper and downstream of the marking system in the machine, for monitoring the presence and absence of cut marks and sort marks in or on the strip of photographic print paper. The sensors are coupled to a logical circuit and associated control circuits which provide the operator of the photoprinting machine with an indication of the operability of the marking system in said machine.