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US3985425A
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Polarizing beam splitting unit
Assignee: Individual
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Filing: 1975-08-18
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Granted: 1976-10-12
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Expires: 1995-08-18
Abstract
Abstract The polarizing beam splitting unit comprises a filter in the form of a layer of polarizing material which passes light in only one plane. This polarizing layer or filter is sandwiched between two transparent glass substrates, one substrate having a reflection-enhancing coating and the other substrate having an anti-reflection coating. In one embodiment the reflection-enhancing coating consists of a single layer of cerium oxide, and in a second embodiment the coating consists of layers of zinc sulphide, magnesium fluoride and silicon dioxide. In both situations the anti-reflection coating consists of magnesium fluoride. The polarizing beam splitting unit is employed in a composite photography system.
Inventors
- 👤 Roy A. Clapp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 13:11
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/10; G02B27/14; G02B27/142; G02B27/28; G02B27/283
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
46 words
A polarizing beam splitting unit comprising a first transparent substrate having a reflection-enhancing coating on one surface thereof, a second transparent substrate having a reflection-reducing coating on one surface thereof, and a sheet of polarizing material between said substrates and secured to the other surfaces thereof.
Claim 2
Dependent Claim
46 words
A polarizing beam splitting unit comprising a first transparent substrate having a reflection-enhancing coating on one surface thereof, a second transparent substrate having a reflection-reducing coating on one surface thereof, and a sheet of polarizing material between said substrates and secured to the other surfaces thereof.
Claim 3
Dependent Claim
28 words
A beam splitting unit in accordance with claim 1 in which said reflection-enhancing coating includes a material selected from the group consisting of cerium oxide and zinc sulphide.
Claim 4
Dependent Claim
17 words
A beam splitting unit in accordance with claim 2 in which said anti-reflection coating is magnesium fluoride.
Claim 5
Dependent Claim
29 words
A beam splitting unit in accordance with claim 3 in whch said substrates are glass, said one and said other surface of each substrate being optically flat and parallel.
Claim 6
Dependent Claim
21 words
A beam splitting unit in accordance with claim 4 in which said substrates are cemented to said sheet of polarizing material.
Claim 7
Dependent Claim
47 words
A beam splitting unit in accordance with claim 1 in which said reflection-enhancing coating comprises a layer of zinc sulphide deposited on said second substrate, a layer of magnesium fluoride on said zinc sulphide layer and an outer layer of silicon dioxide on said magnesium fluoride layer.
Claim 8
Dependent Claim
20 words
A beam splitting unit in accordance with claim 6 in which said anti-reflection coating constitutes a layer of magnesium fluoride.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-10-12 | 1980-04-12 | 1980-10-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-10-12 | 1984-04-12 | 1984-10-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-10-12 | 1988-04-12 | 1988-10-12 | $7700.00 | Window Closed / Lapsed |