Patent US3271521A successfully refreshed from Google Patents.
US3591375A
Expired / Lapsed
US
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Method of printing positives from color negatives whose subjects integrate to blue
Assignee: Ilford Imaging UK Ltd
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Filing: 1968-07-15
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Granted: 1971-07-06
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Expires: 1988-07-15
Abstract
Abstract THIS APPLICATION DESCRIBES A METHOD OF PRINTING POSITIVES FROM MULTICOLOUR NEGATIVES WHEREIN FOR EACH COLOUR COMPONENT OF PRINTING LIGHT, RED, GREEN, AND BLUE, PRINTING CONTINUES UNTIL A PREDETERMINED INTEGRAL OF LIGHT AGAINST TIME HAS BEEN ADMINISTERED TO THE PRINT MATERIAL AS MEASURED BY AN EXPOSURE CONTROL MEANS, SAID PREDETERMINED INTEGRAL BEING SUBSTANTIALLY CONSTANT FOR NEGATIVES REPRESENTING SUBJECTS INTEGRATING TO GREY, THE IMPROVEMENT WHICH COMPRISES REDUCING THE SAID PREDETERMINED INTEGRAL IN RESPONSE TO MEANS FOR DETECTING AN ABNORMALLY LOW RATIO OF INTEGRATED TRANSMITTANCE OF THE NEGATIVE TO BLUE LIGHT RELATIVE TO LIGHT OF LONGER WAVELENGTH.
Inventors
- 👤 Denis Manktelow Neale
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 09:02
CPC Classifications
G; G03; G03B; G03B27/00; G03B27/72; G03B27/73; G03B27/735
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) | 1974-07-05 | 1975-01-04 | 1975-07-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-05 | 1979-01-04 | 1979-07-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-05 | 1983-01-04 | 1983-07-06 | $7700.00 | Window Closed / Lapsed |