Patent US3449753A successfully refreshed from Google Patents.
US3449753A
Expired / Lapsed
US
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Apparatus for controlling contrast in electrostatic printers
Assignee: Unisys Corp
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Filing: 1965-02-01
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Granted: 1969-06-10
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Expires: 1985-02-01
Abstract
No abstract record available.
Inventors
- 👤 David A Starr Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 21:39
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/22; G03G15/32; G03G15/321; G03G15/325
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2777957A
Cited
US2879395A
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US2817765A
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US3004819A
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US3068479A
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US3372400A
Cited
US3307198A
Cited
US3358289A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-06-09 | 1972-12-09 | 1973-06-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-06-09 | 1976-12-09 | 1977-06-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-06-09 | 1980-12-09 | 1981-06-10 | $7700.00 | Window Closed / Lapsed |