US3567447A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for making masks photographically
Assignee: International Business Machines Corp
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Filing: 1967-07-03
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Granted: 1971-03-02
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Expires: 1987-07-03
Abstract
Abstract A PROCESS OF PRODUCING MASKS PHOTOGRAPHICALLY BY FORMING A DEVELOPED COLLODIAL SILVER IMAGE IN A GELATIN COAING ON A GLASS PLATE AND HEATING THE COATING, AFTER WHICH THE NON-IMAGE AREAS OF THE COATING ARE SELECTIVELY REMOVED BY A GELATIN REMOVING LIQUID SUCH AS AQUEOUS SODIUM HYPOCHLORITE. THE HEATING RENDERS THE SILVER IMAGE AREAS OF THE GELATIN COATING MORE RESISTANT TO THE ACTION OF THE GELATIN REMOVING LIQUID SO THAT THE NON-IMAGE AREAS MAY BE SELECTIVELY REMOVED.
Inventors
- 👤 Nirmal Chand
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 15:03
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/54; G03C; G03C5/00; G03C5/26; G03C5/29; G03C5/315; G03C5/40
Claims Analysis
Total Claims: 0
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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) | 1974-03-01 | 1974-08-31 | 1975-03-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-01 | 1978-08-31 | 1979-03-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-01 | 1982-08-31 | 1983-03-02 | $7700.00 | Window Closed / Lapsed |