Patent US3615436A successfully refreshed from Google Patents.
US3615436A
Expired / Lapsed
US
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Self-developing photographic process with liquid trap
Assignee: Polaroid Corp
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Filing: 1967-06-02
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Granted: 1971-10-26
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Expires: 1987-06-02
Abstract
Abstract A photographic film assemblage comprising a pair of sheetlike elements, one of which includes a photosensitive area adapted to be exposed and processed by an alkaline processing liquid distributed in a layer between the two elements to form a visible transfer image. The film assemblage includes means defining a liquid trapping and retaining space near one edge of the area adapted to be exposed, for collecting and retaining excess processing liquid, and liquid permeable means impregnated with an acid located in the trapping and retaining space for neutralizing the excess processing liquid collected therein. In a preferred film structure and method, the two sheets are retained together during and subsequent to processing, one of the sheets is transparent to provide for viewing an image formed between the sheets and the liquid trapping and retaining space is located between the sheets very close to the area containing the visible image.
Inventors
- 👤 John E Campbell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 20:37
CPC Classifications
G; G03; G03D; G03D9/00; G03D9/02; G03B; G03B17/00; G03B17/28; G03B17/32; G03B17/34; G03C; G03C8/00; G03C8/42; G03C8/44; G03C8/46; G03C8/52
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
48 words
A photographic film assemblage as defined in claim 1 wherein said processing liquid includes an opacifying agent capable, when spread between said first and second sheets, of forming an opaque layer for masking a visible image formed in said photosensitive material in said area of said first sheet.
Claim 2
Dependent Claim
70 words
A photographic film assemblage as defined in claim 1, wherein said binding means include a strip of a substantially liquid impermeable sheet Material secured to the outer surfaces of said sheets at marginal portions there of in the region of said opposite edge of said area and said impermeable strip cooperates with recesses formed in said marginal portions of at least one of said sheets to provide said liquid-retaining spaces.
Claim 3
Dependent Claim
22 words
A photographic film assemblage as defined in claim 1, wherein said absorbent material comprises a layer of absorbent paper containing an acid.
Claim 4
Dependent Claim
26 words
A photographic film assemblage as defined in claim 1, wherein said absorbent material comprises an alkaline solution-permeable layer of a coatable, film-forming polymer containing an acid.
Claim 5
Independent Claim
218 words
The method of producing a photographic print utilizing a photographic film assemblage comprising: superposing a photosensitive sheet with a second transparent sheet; securing said sheets to one another at the margins of an area of said photosensitive sheet adapted to be exposed by binding means secured to the margins of said sheets; exposing said area of said photosensitive sheet through said second sheet to form an image in said photosensitive sheet; introducing an aqueous alkaline processing liquid between said sheets at one edge of said area and spreading said liquid as a layer between said sheets in contact with said area toward the opposite edge thereof; reacting said liquid with said exposed photosensitive sheet in said area to form an image visible through said second sheet; collecting and retaining excess processing liquid within said film assemblage in a space defined by said binding means located closely adjacent and in direct communication with said region between said area and said second sheet at said opposite edge of said area; retaining said film assemblage intact with said sheets in superposition; and contacting said excess processing liquid retained in said space with an acid contained in said space to neutralize said alkaline processing liquid and prevent deterioration of said visible image formed between said sheets in the vicinity of said space.
Claim 6
Dependent Claim
60 words
A photographic method as defined in claim 6, wherein said processing liquid includes an opacifying agent, said opacifying agent is distributed between said photosensitive sheet and said second sheet to form an opaque layer capable of masking a visible image formed in said photosensitive sheet and the first-mentioned visible image is formed between said opaque layer and said second sheet.
Claim 7
Dependent Claim
43 words
A photographic method as defined in claim 6, wherein said excess processing liquid is collected and retained in a space separated from said region by a distance less than 15 times the maximum thickness of said layer of liquid spread between said sheets.
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 |