US3563634A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System and apparatus for improving the contrast of or for the binarising of analogue density patterns
Assignee: NAT RES DEV
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Filing: 1967-12-14
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Granted: 1971-02-16
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Expires: 1987-12-14
Abstract
Abstract OPTICAL ARRANGEMENTS FOR ISOLATING CHOSEN SPATIAL FREQUENCY COMPONENTS OF AN ANALOGUE FORM DENSITY OR INTENSITY OBJECT PATTERN, E.G. A PRINTED CHARACTER, IN WHICH A TRANSPARENCY OF THE OBJECT PATTERN IS DISPOSED IN A COLLIMATED LIGHT BEAM AND BY MEANS OF AN OPTICAL SYSTEM A DIFFRACTION PATTERN IS PRODUCED IN OR BEYOND THE FOURIER PLANE, SAID FOURIER PLANE CONTAINING A LIGHT STOP HAVING AN ANNULAR PASS APERTURE AND THE LIGHT PASSING SAID STOP BEING IMAGED IN A RESULTANT IMAGE PLANE.
Inventors
- 👤 John Ronald Parks
- 👤 Ralph Eric Rengger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 00:30
CPC Classifications
G; G06; G06V; G06V10/00; G06V10/88
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) | 1974-02-15 | 1974-08-17 | 1975-02-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-02-15 | 1978-08-17 | 1979-02-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-02-15 | 1982-08-17 | 1983-02-16 | $7700.00 | Window Closed / Lapsed |