US3682528A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Infra-red interference filter
Assignee: Optical Coating Laboratory Inc
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Filing: 1970-09-10
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Granted: 1972-08-08
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Expires: 1990-09-10
Abstract
Abstract Infra-red reflecting interference filter having a substrate capable of transmitting visible energy and having a surface with a precoat layer adherent thereto formed of a thin layer of material and a layer of silver deposited on the thin layer and having a thickness so that it is highly transmitting of visible energy and highly reflecting of infra-red energy.
Inventors
- 👤 Joseph H Apfel
- 👤 Robert M Gelber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 00:10
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/20; G02B5/28; G02B5/281; G02B5/282
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
162 words
In a filter, a substrate having a surface, said substrate being formed of a material capable of transmitting visible energy and a coating formed on said surface, said coating comprising first and second bi-layers, with each of the said bi-layers consisting of a layer of silver having a thickness ranging from 55 to 130 angstroms and a precoat layer having a thickness which is in excess of a minimum value of approximately 5 Angstroms and has a maximum thickness which is ineffective in changing the optical properties of the filter but causing the silver layer to behave as a homogenous metal slab, said coating having a transmission which is over approximately 70 percent in the region from 400 to 700 mm and below approximately 10 percent in the region of 700 to 2500 mm and a reflection which is approximately 10 percent average from 400 to 700 mm and increases to over 90 percent in the range of 700 to 2500 mm.
Claim 2
Dependent Claim
162 words
In a filter, a substrate having a surface, said substrate being formed of a material capable of transmitting visible energy and a coating formed on said surface, said coating comprising first and second bi-layers, with each of the said bi-layers consisting of a layer of silver having a thickness ranging from 55 to 130 angstroms and a precoat layer having a thickness which is in excess of a minimum value of approximately 5 Angstroms and has a maximum thickness which is ineffective in changing the optical properties of the filter but causing the silver layer to behave as a homogenous metal slab, said coating having a transmission which is over approximately 70 percent in the region from 400 to 700 mm and below approximately 10 percent in the region of 700 to 2500 mm and a reflection which is approximately 10 percent average from 400 to 700 mm and increases to over 90 percent in the range of 700 to 2500 mm.
Claim 3
Dependent Claim
21 words
A filter as in claim 19 wherein each of said precoat layers has a thickness ranging from 5 to 20 angstroms.
Claim 4
Dependent Claim
17 words
A filter as in claim 2 wherein each of said precoat layers is formed of a metal.
Claim 5
Dependent Claim
16 words
A filter as in claim 3 wherein each of said precoat layers is formed of nickel.
Claim 6
Dependent Claim
20 words
A filter as in claim 1 wherein said coating includes at least one layer of dielectrical material overlying said surface.
Claim 7
Dependent Claim
17 words
A filter as in claim 1 wherein said coating includes an additional dielectric layer overlying each bi-layer.
Claim 8
Dependent Claim
14 words
A filter as in claim 1 which has a neutral appearance in both directions.
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) | 1975-08-08 | 1976-02-07 | 1976-08-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-08 | 1980-02-07 | 1980-08-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-08 | 1984-02-07 | 1984-08-08 | $7700.00 | Window Closed / Lapsed |