Patent US4481651A successfully refreshed from Google Patents.
Patent US3565516A successfully refreshed from Google Patents.
US3565516A
Expired / Lapsed
US
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Extended range underwater optics system
Assignee: United States Department of the Navy
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Filing: 1969-07-25
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Granted: 1971-02-23
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Expires: 1989-07-25
Abstract
Abstract AN EXTENDED RANGE UNDERSEA CLEAR WATER VIEWING SYSTEM CONSERVING THE CLEAR WATER SUPPLY CAPABILITY. RANGE IS EXTENDED BY CONTAINING FLOW OF CLEAR WATER FORWARD VIEWED OBJECT BY MEANS OF SOLID BODY BOUNDARIES OR BY FLOWING TURBID WATER BOUNDARIES, OR BOTH, AND BY GENERATING VORTEX FLOW.
Inventors
- 👤 John F Thomas
- 👤 Karl H Keller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 16:23
CPC Classifications
G; G02; G02B; G02B23/00; G02B23/16; G02B23/22
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) | 1974-02-22 | 1974-08-24 | 1975-02-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-02-22 | 1978-08-24 | 1979-02-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-02-22 | 1982-08-24 | 1983-02-23 | $7700.00 | Window Closed / Lapsed |