US4207157A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for controlling halogen ion concentration in a photographic processing solution
Assignee: Fujifilm Holdings Corp
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Filing: 1978-08-21
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Granted: 1980-06-10
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Expires: 1998-08-21
Abstract
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.
Inventors
- 👤 Hiroyuki Hirai
- 👤 Sachio Matsushita
- 👤 Isao Tsuyuki
- 👤 Kazumi Watase
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 14:37
CPC Classifications
G; G03; G03D; G03D3/00; G03D3/02; G03D3/06; G03D3/065; G03C; G03C5/00; G03C5/26; G03C5/29; G03C5/31
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
84 words
A method of controlling the halogen ion concentration of a photographic processing solution, comprising the steps of: (a) determining the concentration of halogen ions in a photographic processing solution by adding silver ions in a titration reaction with said halogen ions, wherein an endpoint of said reaction is detected by sensing a change in electrical potential of said reaction system by means of a halogen ion sensitive electrode system, and (b) controlling the removal of halogen ions as a function of the concentration determination.
Claim 2
Independent Claim
84 words
A method of controlling the halogen ion concentration of a photographic processing solution, comprising the steps of: (a) determining the concentration of halogen ions in a photographic processing solution by adding silver ions in a titration reaction with said halogen ions, wherein an endpoint of said reaction is detected by sensing a change in electrical potential of said reaction system by means of a halogen ion sensitive electrode system, and (b) controlling the removal of halogen ions as a function of the concentration determination.
Claim 3
Dependent Claim
24 words
The method of claim 1, wherein the silver ions are added to the photographic processing solution by adding thereto an aqueous silver nitrate solution.
Claim 4
Dependent Claim
25 words
The method of claim 1, wherein the silver ions are added to the photographic processing solution as silver ions from a silver electrode by electrolysis.
Claim 5
Dependent Claim
25 words
The method of claim 1, wherein the silver ions are added to the photographic processing solution according to the halogen ion content in the solution.
Claim 6
Dependent Claim
13 words
The method of claim 1, wherein the halogen ions are removed by electrodialysis.
Claim 7
Dependent Claim
18 words
The method of claim 1, wherein the halogen ions are removed by electrolysis through an anion exchange membrane.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-06-10 | 1983-12-10 | 1984-06-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-06-10 | 1987-12-10 | 1988-06-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-06-10 | 1991-12-10 | 1992-06-10 | $7700.00 | Window Closed / Lapsed |