US3679291A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Filter with neutral transmitting multilayer coating having asymmetric reflectance
Assignee: Optical Coating Laboratory Inc
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Filing: 1970-04-21
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Granted: 1972-07-25
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Expires: 1990-04-21
Abstract
Abstract Filter with neutral transmitting multilayer coating having asymmetric reflectance with strong color on one side. Certain embodiments have low reflectance on the other side over a broad spectral region which covers at least a visible portion of the electromagnetic spectrum. Certain of the filters have a single metal layer with at least one dielectric layer, whereas others of the filters have a pair of metal or absorbing layers, each of which is paired with one or more dielectric layers.
Inventors
- 👤 Joseph H Apfel
- 👤 Robert M Gelber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 12:23
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/20; G02B5/205
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
20 words
A filter as in claim 1 wherein the reflectance from said one surface of the coating is above 10 percent.
Claim 2
Dependent Claim
29 words
A filter as in claim 1 in which at least two metal layers are provided and in which a dielectric layer is associated with eAch of the metal layers.
Claim 3
Dependent Claim
19 words
A filter as in claim 3 wherein said multilayer coating includes matching layers on opposite sides of the same.
Claim 4
Dependent Claim
23 words
A filter as in claim 1 wherein said metal layer is formed of Inconel and the dielectric layer is formed of titanium dioxide.
Claim 5
Dependent Claim
26 words
A filter as in claim 3 wherein said metal layers are formed of nickel and wherein said dielectric layers are formed of a high index material.
Claim 6
Dependent Claim
15 words
A filter as in claim 4 wherein said matching layers are formed of magnesium fluoride.
Claim 7
Dependent Claim
27 words
A filter as in claim 1 wherein there are provided a plurality of dielectric layers and wherein said dielectric layers are formed of two different non-absorbing materials.
Claim 8
Dependent Claim
18 words
A filter as in claim 8 wherein said two different non-absorbing materials are titanium dioxide and silicon dioxide.
Claim 9
Dependent Claim
33 words
A filter as in claim 1 wherein at least three metal layers are provided and each of the metal layers has associated therewith at least one dielectric layer to form metal dielectric pairs.
Claim 10
Dependent Claim
47 words
A filter as in claim 1 wherein there are provided at least three metal layers and wherein said metal layers have at least one dielectric layer associated therewith, certain of said metal layers having at least two dielectric layers associated therewith to form a metal dielectric combination.
Claim 11
Dependent Claim
129 words
In a multi-chromatic filter, a substantially transparent substrate having a surface and a multilayer coating deposited on said surface, said multilayer coating having at least first and second metal layers, each of said metal layers having a dielectric layer paired therewith so that the reflectance from the pair does not approach an appreciable fraction of the reflectance of the material being utilized for the metal layer, said filter being substantially neutral in transmission and having a transmission substantially below 60 percent, said coating on the one side having a low reflectance which is below approximately 4 percent and on the other side having at least a moderate reflectance which changes as a function of wavelength to give an appearance of color in the visible region from the other side.
Claim 12
Dependent Claim
18 words
A filter as in claim 12 wherein said metal layers have a thickness less than 200 Angstroms each.
Claim 13
Dependent Claim
26 words
A filter as in claim 12 wherein said metal layers are formed of nickel and wherein said dielectric layers are formed of a high index material.
Claim 14
Dependent Claim
25 words
A filter as in claim 12 wherein certain of said metal layers are provided with an additional dielectric layer to provide a metal dielectric combination.
Claim 15
Dependent Claim
15 words
A filter as in claim 15 wherein two of said metal dielectric combinations are provided.
Claim 16
Dependent Claim
18 words
A filter as in claim 12 wherein said coating includes matching layers on opposite ends of the coating.
Claim 17
Dependent Claim
15 words
A filter as in claim 17 wherein said matching layers are formed of magnesium fluoride.
References Cited (Backward Citations)
US2366687A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-25 | 1976-01-24 | 1976-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-25 | 1980-01-24 | 1980-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-25 | 1984-01-24 | 1984-07-25 | $7700.00 | Window Closed / Lapsed |