Sensing registration without a registration “eye” mark

Challenge:

Registration marks (“eye” marks) on films are used to indicate the occurrence of a printed pattern being repeated on that film.  They are typically along the outer edge of the film (the margin), where no other graphic printing exists.  The registration mark sensor must reliably sense the event of the registration mark passing in its view and signal the repeat event.  However, occasionally, a customer may have a film where no registration marks were printed.  The customer realizes that if a sensor can sense off the printed graphic pattern on the film instead, he may have a solution.  The challenge is that, for any given color of graphic, or any specific physical location on that film, as the film travels, other printed graphics will also pass in time in view of that same sensor, and the sensor isn’t able to distinguish one printed graphic from another.  True color sensors usually can not be used as they will experience all different transitions of colored graphic as the film progresses.

Another variation of this situation is if a cylindrical container/bottle has printing on it, and the customer wants to apply a spot label on a specific location onto the container during the time it is spinning, without a registration mark in a unique location to trigger off of, the task seems impossible.

Solution:

Not all applications can benefit from this proposal, but it may be possible to utilize 2, or perhaps 3, sensors, each looking at specific portion of the graphics that, collectively for the 2 or 3 sensors, there is only 1 unique time that all sensors see this situation….. either as the film passes during the repeat of the printed pattern, or as the round container spins through a single revolution.  This process is of identifying those 2 or 3 locations that occur once and simultaneously per repeat pattern is mentally challenging.  The analogy is like an more sophisticated inspection task, where all 2 or three conditions must be simultaneously satisfied in order to accept the inspected product.  But if such sensor locations can be identified, then by connecting the 2 or 3 sensor outputs together in a logic AND function, only one output will be achieved per repeat pattern.  The electrical connection of all such sensors is in parallel, but the corresponding light operate/dark operate states of each of the sensors must be selected to provide the logic AND function.

Net Value to our Customers:

Whether you have an easy, or more challenging type application, give us a call.  Chances are we may have either the sensor and/or the experience to solve it.  Excel Automation, and Eagle Sensors & Controls, have years of experience, and are application-oriented Authorized Distributors of numerous products for Industrial Automation, and LED Lighting.