Patent US2167439A successfully refreshed from Google Patents.
Patent US3709580A successfully refreshed from Google Patents.
US3709580A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Extended range polarization target
Assignee: United States Department of the Navy
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Filing: 1971-03-18
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Granted: 1973-01-09
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Expires: 1991-03-18
Abstract
Abstract A reflector, particularly useful for underwater use, comprising a base material having angled surfaces for retro-reflecting an incident beam of light back substantially parallel to the incident beam, and means for polarizing the reflected beam into the same circular polarization handedness as the incident beam.
Inventors
- 👤 R Fugitt
- 👤 P Heckman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 12:44
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/28; G02B27/281; G02B23/00; G02B23/16; G02B23/22
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
54 words
A REFLECTOR, PARTICULARLY USEFUL FOR UNDERWATER USE, COMPRISING: A BASE MATERIAL; THE BASE MATERIAL HAVING A SINGLE-REFLECTION RETRO-REFLECTIVE, DIMPLED, SURFACE, THE DIMPLES BEING IN THE RANGE OF 1.5MM DEEP, WITH A RADIUS OF CURVATURE OF APPROXIMATELY 3.0MM, AND SPACED APPROXIMATELY 6MM APART; AND A SHEET OF BIREFRINGENT QUARTER-WAVE PLATE DISPOSED UPON THE DIMPLED SURFACE.
Claim 2
Dependent Claim
54 words
A REFLECTOR, PARTICULARLY USEFUL FOR UNDERWATER USE, COMPRISING: A BASE MATERIAL; THE BASE MATERIAL HAVING A SINGLE-REFLECTION RETRO-REFLECTIVE, DIMPLED, SURFACE, THE DIMPLES BEING IN THE RANGE OF 1.5MM DEEP, WITH A RADIUS OF CURVATURE OF APPROXIMATELY 3.0MM, AND SPACED APPROXIMATELY 6MM APART; AND A SHEET OF BIREFRINGENT QUARTER-WAVE PLATE DISPOSED UPON THE DIMPLED SURFACE.
Claim 3
Dependent Claim
55 words
A reflector particularly useful for underwater use, comprising: a plastic substrate; a plurality of transparent glass, microscopic, spheres imbedded in the substrate; the surfaces of intersection of the spheres and the substrate forming a reflective surface; and a sheet of birefringent quarter-wave plate disposed upon, or adjacent to, the imbedded spheres, parallel to the substrate.
Claim 4
Dependent Claim
55 words
A reflector particularly useful for underwater use, comprising: a plastic substrate; a plurality of transparent glass, microscopic, spheres imbedded in the substrate; the surfaces of intersection of the spheres and the substrate forming a reflective surface; and a sheet of birefringent quarter-wave plate disposed upon, or adjacent to, the imbedded spheres, parallel to the substrate.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-01-09 | 1976-07-10 | 1977-01-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-09 | 1980-07-10 | 1981-01-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-09 | 1984-07-10 | 1985-01-09 | $7700.00 | Window Closed / Lapsed |