Apparatus for treating webs of photographic material or the like
AssigneeAgfa-Gevaert
InventorsFriedrich Hujer, Ferdinand Schaner
Life of this patent
Estimating the term…
Abstract
Apparatus for subdividing webs of photographic paper into discrete prints has a detector which scans marks applied to the web for the purpose of arresting the drive for the web at the exact moment when the central portion of a frame line between two successive images on the web is in register with the knives. The signals which are furnished by the detector can be used to arrest the drive only within a short interval of time which begins shortly or immediately before a mark reaches the detector. This prevents the detector from arresting the drive in response to detection of a flaw or a particle of foreign matter whose effect upon the detector is similar to that of a mark.
Claims18
In an apparatus for treating a web which is provided with substantially uniformly spaced intentionally applied indicia, particularly for subdividing a web of photographic material into sections each of which carries the image of a film frame, a combination comprising advancing means operable to advance the web lengthwise along a predetermined path detector means adjacent to a portion of said path and arranged to scan the web for the presence of said indicia and to produce signals in response to detection of indicia;
- arresting means activatable to terminate the operation of said advancing means in response to said signals;
- means for deactivating said arresting means not later than on start of operation of said advancing means;
- means for activating said arresting means in response to transport of the web through a predetermined distance which is only slightly less than the distance between a pair of neighboring indicia on the web so that said arresting means can terminate the operation of said advancing means only after the web is transported through said predetermined distance to thus insure that said arresting means cannot be activated in response to signals produced by said detector means on detection of unintentionally applied indicia during transport of the web through said predetermined distance;
- and means for treating the web on stoppage of said advancing means.
Dependencies are inferred from the claim text.