US3762923A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for processing black and white photographic silver halidematerial
Assignee: Fujifilm Holdings Corp
•
Filing: 1971-03-16
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Granted: 1973-10-02
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Expires: 1991-03-16
Abstract
Abstract A method for processing black-and-white negative photographic silver halide materials which comprises (a) developing the exposed black-and-wite photographic material, (b) bleaching said photographic material without oxidizing and dissolving the silver in a bleaching solution, and (c) subsequently developing said photographic material again with a black-and-white developer.
Inventors
- 👤 Yama M Sug
- 👤 S Ishiguro
- 👤 N Sugiyama
- 👤 H Iwano
- 👤 Y Iijima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 06:20
CPC Classifications
G; G03; G03C; G03C5/00; G03C5/26; G03C5/29; G03C5/40; G03C5/44; Y; Y10; Y10S; Y10S430/00; Y10S430/15
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
23 words
The method of claim 1, wherein the first development step is carried out with a develOper containing hydroquinone and a sodium sulfite-paraformaldehyde adduct.
Claim 2
Dependent Claim
25 words
The method of claim 2, wherein said developer further contains at least one member selected from the group consisting of ascorbic acid and sodium sulfite.
Claim 3
Dependent Claim
16 words
The method of claim 1, wherein said bleaching solution contains an oxidizing agent and a halide.
Claim 4
Independent Claim
65 words
A method for treating an exposed black-and-white negative photographic material to obtain a high contrast silver image, wherein the chloride content of said silver halide material is present in an amount of at least 70 percent, which comprises the steps of: a. developing, b. stopping, c. bleaching at a pH of at least 1, d. rinsing, e. negative-developing, f. stopping, g. fixing, and h. washing.
Claim 5
Independent Claim
64 words
A method for treating an exposed black-and-white negative photographic material to obtain a high contrast silver image, wherein the chloride content of said silver halide material is present in an amount of at least 70 mol percent, which comprises the steps of: a. developing, b. bleaching at a pH of at least 1, c. rinsing, d. negative-developing, e. stopping, f. fixing, and g. washing.
Claim 6
Independent Claim
63 words
A method for treating an exposed black-and-white negative photographic material to obtain a high contrast silver image, wherein the chloride content of said silver halide material is present in an amount of at least 70 mol percent, which comprises the steps of: a. developing, b. bleaching at a pH of at least 1, c. rinsing d. mono-bath negative-developing and fixing, and e. washing.
Claim 7
Independent Claim
61 words
A method for treating an exposed black-and-white negative photographic material to obtain a high contrast silver image, wherein the chloride content of said silver halide material is present in an amount of at least 70 mol percent, which comprises the steps of: a. developing, b. bleaching at a pH of at least 1, c. mono-bath negative-developing and fixing, and d. washing.
Claim 8
Dependent Claim
21 words
The method of claim 1, wherein said bleaching step is carried out over a period of from 5 to 100 seconds.
Claim 9
Dependent Claim
21 words
The method of claim 1, wherein said bleaching step is carried out over a period of from 10 to 30 seconds.
Claim 10
Dependent Claim
22 words
The method of claim 1, wherein said second developing step is carried out over a period of from 10 to 200 seconds.
Claim 11
Dependent Claim
22 words
The method of claim 1, wherein said second developing step is carried out over a period of from 30 to 80 seconds.
Claim 12
Dependent Claim
22 words
The method of claim 1, further comprising at least one stopping, rinsing and washing step conducted after treating steps (a) through (c).
Claim 13
Dependent Claim
20 words
The method of claim 1, further comprising a fixing step, which step takes place either during or after step (c).
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) | 1976-10-01 | 1977-04-02 | 1977-10-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-01 | 1981-04-02 | 1981-10-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-01 | 1985-04-02 | 1985-10-02 | $7700.00 | Window Closed / Lapsed |