US4483899A
Expired / Lapsed
US
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Infrared reflection-preventing film
Assignee: Topcon Corp
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Filing: 1982-11-29
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Granted: 1984-11-20
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Expires: 2002-11-29
Abstract
Abstract An infrared reflection-preventing film including a titanium oxide layer disposed on an infrared optical substrate and a film of at least one second layer laid further on said first layer.
Inventors
- 👤 Tetsuo Kuwabara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 02:00
CPC Classifications
G; G02; G02B; G02B1/00; G02B1/10; G02B1/11; G02B1/113; G02B1/115; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24942; Y10T428/2495
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
86 words
An infrared reflection-preventing film comprising an infrared optical substrate and at least a first layer of titanium oxide on the optical substrate and a second layer of zinc sulfide on the first layer, the layers satisfying the relationships: n.sub.1 d.sub.1 +n.sub.2 d.sub.2 =λo/4 and 10 nm≦n.sub.1 d.sub.1 ≦50 nm where n 1 d 1 is an optical thickness of said first layer, n 2 d 2 is an optical thickness of said second layer, and λo is a center wavelength of a desired reflection-preventing wavelength band.
Claim 2
Dependent Claim
86 words
An infrared reflection-preventing film comprising an infrared optical substrate and at least a first layer of titanium oxide on the optical substrate and a second layer of zinc sulfide on the first layer, the layers satisfying the relationships: n.sub.1 d.sub.1 +n.sub.2 d.sub.2 =λo/4 and 10 nm≦n.sub.1 d.sub.1 ≦50 nm where n 1 d 1 is an optical thickness of said first layer, n 2 d 2 is an optical thickness of said second layer, and λo is a center wavelength of a desired reflection-preventing wavelength band.
Claim 3
Dependent Claim
20 words
The infrared reflection-preventing film of claim 1 wherein the substrate is selected from the group consisting of Ge or Si.
Claim 4
Dependent Claim
21 words
The infrared reflection-preventing film of claim 1 wherein the film contains a third layer of MgF 2 on said second layer.
References Cited (Backward Citations)
US3601471A
Cited
US4436363A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-11-20 | 1988-05-21 | 1988-11-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-11-20 | 1992-05-21 | 1992-11-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-11-20 | 1996-05-21 | 1996-11-20 | $7700.00 | Window Closed / Lapsed |