Photographic developer replenishment

Abstract

Abstract DEVELOPER REPLENISHER IS ADDED TO A BATH OF PHOTOGRAPHIC DEVELOPER, IN ACCORDANCE WITH MONITORING OF A TEST STRIP OF PHOTOGRAPHIC MATERIAL DEVELOPER BY DEVELOPER SAMPLED FROM THE BATH, FOR THE PURPOSE OF COMPENSATING FOR ANY LOSS IN ACTIVITY THAT OTHERWISE WOULD OCCUR BECAUSE OF USE, AGING, OR OTHER REASON. THE PHOTOSENSITIVE TEST STRIP IS TRANSPORTED SUCCESSIVELY THROUGH AN EXPOSURE CHAMBER WHEREIN IT IS EXPOSED TO ACTINIC LIGHT, A DEVELOPMENT CHAMBER WHEREIN THE EXPOSED STRIP IS DEVELOPED BY THE SAMPLE OF DEVELOPER, AND FINALLY A MONITORING CHAMBER WHEREIN THE DEVELOPED OPTICAL DENSITY OF THE STRIP DETERMINES THE AMOUNT OF LIGHT PASSING FROM A NON-ACTINIC LIGHT SOURCE TO A PHOTORESISTIVE ELEMENT IN AN ELECTRONIC SYSTEM FOR CONTROLLING THE ADDITION OF REPLENISHER TO THE DEVELOPER BATH. THE MONITORED DENSITY IS CHECKED CONTINUOUSLY AGAINST A VALUE CORRESPONDING TO AN ACCEPTABLE PLATEAU OF DEVELOPER ACTIVITY, AND ALSO PERIODICALLY FOR ANY DECREASE IN DENSITY AS COMPARED WITH THE RESULTS OBTAINED WHEN LAST PREVIOUSLY CHECKED, AND IF DEFICIENT IS ADJUSTED UPWARD BY INTERMITTENT ADDITION OF REPLENISHER IN ACCORDANCE WITH THE PREVAILING RATE OF DECREASE IN DENSITY.

Inventors

• 👤 Clarence S Ost

Bibliographic Details