Method and apparatus for controlling halogen ion concentration in a photographic processing solution
AssigneeFuji Photo Film Co., Ltd.
InventorsHiroyuki Hirai, Sachio Matsushita, Isao Tsuyuki, Kazumi Watase
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Abstract
The concentration of halogen ions in a photographic developer is controlled at an almost constant value by determining the concentration of halogen ions in the developer by detecting the change in electric potential caused by the addition of silver ions to the solution, and controlling the electrical current supplied to a halogen ion removing means, such as an electrodialysis or an electrolysis unit having an anion exchange membrane, based on the result of the determination of halogen ions. By this method the amount of complementary developer added to a fatigued developer solution can be greatly reduced.
Claims6
An apparatus for controlling the concentration of halogen ions in a photographic processing solution, comprising:
- (a) means for sampling a photographic processing solution,
- (b) means for determining concentration of the halogen ions in the sampled processing solution according to the change in electric potential caused by the addition of silver ions,
- (c) means for removing halogen ions from the processing solution, and
- (d) means for controlling the halogen ion removing means in response to the output of the halogen ion determining means.
Dependencies are inferred from the claim text.