US3616435A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Integration-controlled apparatus
Assignee: Eastman Kodak Co
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Filing: 1969-03-06
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Granted: 1971-10-26
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Expires: 1989-03-06
Abstract
Abstract Photographic developing solutions dissolve silver during film processing. Processing occurs during a normal workday. Electrolytic recovery of silver may occur during, and after, the workday. The electrolyzing current is (preferably) set in proportion to a quiescent silver content of the developing solution; and the duration for applying the current is regulated in accordance with the integral of the difference between the rates of input and recovery silver. Other applications of the disclosed invention are possible.
Inventors
- 👤 Brian Favell
- 👤 Richard G Hall
- 👤 Brian Harris
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 17:46
CPC Classifications
C; C25; C25C; C25C7/00; C25C7/06; G; G03; G03D; G03D3/00; G03D3/02; G03D3/06; G03D3/065
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
47 words
The system of claim 1 wherein said integration means (46) produces a signal representing the time integral of the algebraic difference between its two input signals, and said actuable means is responsive to both the said means for actuating and to said short duration disturbances as well.
Claim 2
Dependent Claim
139 words
A photographic film-developing system having a processing portion (10) adapted to receive and be influenced by film, and a control portion adapted to maintain the said processing portion in a substantially quiescent operating condition, said control portion comprising a. first adjustable (26), (18) for substantially steadily modifying the condition of the processing portion, b. second adjustable means (32) for producing a first analog of the rate at which said film influences the condition of said processing portion, c. third adjustable means (30) for producing a second analog of the rate at which said first adjustable means modifies the condition of the processing portion, and d. integration means (46) responsive to said analogs to couple said first adjustable means to said processing portion so long as the time integral of the first analog is greater than that of the second.
Claim 3
Dependent Claim
41 words
The system of claim 3 wherein the first adjustable means is the combination of silver recovery means (18) and a regulatable power supply (24), (26) therefor, said silver recovery means being cooperative with said processing portion to interchange their respective solutions.
Claim 4
Dependent Claim
84 words
The system of claim 4 including means, in addition to said integration means and responsive to the application of film to the processing portion of said system, for coupling the combination of silver recovery means and power supply to said processing portion, whereby silver recovery occurs while said film is being applied to said processing portion and for a duration thereafter which is proportional to the integral of the difference between the rates at which silver is dissolved into and recovered from processing solution.
Claim 5
Dependent Claim
34 words
The system of claim 4 wherein the said power supply is so regulatable that the current through the silver recovery means may be made compatible with the silver content of solution within that means.
Claim 6
Dependent Claim
60 words
The system of claim 5 wherein said second and third adjustable means are potentiometric means, wherein said integration is a reversible integrator element respectively oppositely excitable by means of said potentiometric means, and wherein the said integrator element has a reference condition at which it does not influence the coupling between the first adjustable means and the said processing portion.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-10-25 | 1975-04-26 | 1975-10-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-10-25 | 1979-04-26 | 1979-10-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-10-25 | 1983-04-26 | 1983-10-26 | $7700.00 | Window Closed / Lapsed |