Pako Corporation

Ralph L Charnley

Theodore A Melander

Alfred J Gaskell

An automatic anti-oxidation fluid replenisher system for processors of photosensitive material has an improved, digital electronic control system. The control system includes a digital binary counter which is counted down if use-related chemical replenishment is not occurring in the processor, and is counted up (generally at a different rate) if use-related chemical replenishment is occurring in the processor. When the counter reaches a predetermined value (e.g. zero), a detection circuit triggers anti-oxidation replenishment and resets the counter to its original value for further operation. A special circuit protects against counter roll-over should the counter reach its maximum capacity due to frequent chemical replenishment activity.

Anti-oxidation fluid replenisher control system for processor of

A replenisher system for photographic processors includes an automatic calibration system. A film sensor senses when film approaches the density sensor (and guarantees that the sensor is clear), and the automatic calibration system calibrates the density sensor (or other film parameter sensor) of the replenisher system prior to the film reaching the density sensor. The automatic calibration is performed each time a strip of film enters the processor, and reaches the density sensor, thereby assuring that drift and other variations in density sensor output unrelated to the film density are eliminated. In addition, the automatic calibration system provides a data valid signal after the density sensor has been calibrated to allow the replenisher control to accept the output signals from the density sensor and control the supply of replenisher fluid to the processor only for a limited time interval after calibration (i.e. while film is actually present in the density sensor).

Automatic density measurement calibration for photographic replenishment

An automatic replenishing system for maintaining the chemical concentration of the liquid in a film processing tank, which automatically energizes a replenishing pump at regular timed intervals (e.g. every 30 seconds) regardless of whether or not the control circuitry indicates a need for replenishment, and which includes an element for sensing the density and velocity of the film and for producing a combined signal which controls the running time of the pump after each energization. The replenishing system also includes a second replenishing pump for maintaining the condition of the liquid in the processing tank, which second pump is energized automatically after a predetermined number of said regular timed intervals, or after a predetermined number of said regular timed intervals in which a zero film density or non-use condition has been detected for a preset running time.

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Minneapolis, MN, United States of America

Ralph L Charnley