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US3781090A
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Four layer anti-reflection coating
Assignee: Minolta Co Ltd
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Filing: 1972-11-06
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Granted: 1973-12-25
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Expires: 1992-11-06
Abstract
Abstract A multi-layered anti-reflection coating for use with a glass substrate includes four layers of material, the first layer furthest from the substrate having an optical thickness of a preselected design wavelength, lambda o in the range of 0.260 lambda o > Nld1 > 0.230 lambda o and an index of refraction in the range of 1.35 to 1.62. The second layer having an optical thickness in the range of 0.520 lambda o > N2d2 > 0.400 lambda o and an index of refraction in the range of 2.00 to 2.30. The optical thickness of one of the third and fourth layers is in the range of 0.500 Tau o > N d > 0.250 lambda o while the optical thickness of the other layer of the third and fourth layers is in the range of 0.250 lambda o > N d > 0.060 lambda o. The third layer has an index of refraction in the range of 1.56 to 1.72 and the fourth layer closest to the substrate has an index or refraction in the range of 1.35 to 1.62. The optical thicknesses of the layers can be varied to compensate for any variations from the theoretical design index of refractions.
Inventors
- 👤 H Sumita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 09:39
CPC Classifications
C; C03; C03C; C03C17/00; C03C17/34; C03C17/3411; C03C17/3429; C03C17/3447; C03C17/3452; C03C17/3417; C03C17/3464; C03C17/347; C03C17/3494; G; G02; G02B; G02B1/00; G02B1/10; G02B1/11; G02B1/113; G02B1/115
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
38 words
A multi-layered anti-reflection coating as in claim 1 wherein the substrate has an index of refraction of Ns and the indices of refraction are related as follows, N1 equals N4 and N2 is greater than N3 and Ns.
Claim 2
Dependent Claim
30 words
A multi-layered anti-reflection coating as in claim 1 wherein the first and fourth coating layers are selected from the group consisting of MgF2, SiO2, ThF4, LaF2, Na3(AlF4), Al2O3, and CeF3.
Claim 3
Dependent Claim
27 words
A multi-layered anti-reflection coating as in claim 1 wherein the second coating layer is selected from the group consisting of CeO2, ZrO2, TiO2, Ta2O5, ZnS and ThO2.
Claim 4
Dependent Claim
35 words
A multi-layered anti-reflection coating as in claim 1 wherein the third coating layer is selected from the group consisting of Al2O3, MgO, CeF3, LaF3, NdF3, BeO, InO2, ThOH2 and a mixture of MgO and Al2O3.
Claim 5
Dependent Claim
75 words
A multi-layered anti-reflection coating as in claim 1 wherein the first and fourth coating layer are selected from the group consisting of MgF2, SiO2, ThF4, LaF2, Na3(AlF4), Al2O3, and CeF3; the second coating layer is selected from the group consisting of CeO2, ZrO2, TiO2, Ta2O5, ZnS and ThO2, and the third coating layer is selected from the group consisting of Al2O3, MgO, CeF3, LaF3, NdF3, BeO, InO2, ThOH2 and a mixture of MgO and Al2O3.
Claim 6
Dependent Claim
27 words
A multi-layered anti-reflection coating as in claim 6 wherein the substrate is a glass having an index of refraction Ns in the range of 1.42 to 1.72.
Claim 7
Dependent Claim
125 words
A multi-layered anti-reflection coating for use with a substrate to reduce reflection of energy comprising four layers of material, each layer having an optical thickness of a preselected design wavelength lambda o as follows: 0.260 lambda o > N1d1 > 0.230 lambda o 0.520 lambda o > N2d2 > 0.400 lambda o 0.500 lambda o > N3d3 > 0.060 lambda o 0.500 lambda o > N4d4 > 0.060 lambda o wherein N refers to the index of refraction and d refers to the physical thickness of the layer, the subnumbers corresponding to the layers with N1d1 being the layer furthest from the substrate, the optical thickness of the layers being adjustable to compensate for variations from any design N whereby the design reflectance is maintained.
Claim 8
Dependent Claim
38 words
A multi-layered anti-reflection coating as in claim 8 wherein the substrate has an index of refraction of Ns and the indices of refraction are related as follows, N1 equals N4 and N2 is greater than N3 and Ns.
Claim 9
Dependent Claim
35 words
A multi-layered anti-reflection coating as in claim 8 wherein the substrate has an index of refraction of Ns and the indices of refraction are related as follows: N1 N4 < Ns > N3 < N2.
Claim 10
Dependent Claim
66 words
A multi-layered anti-reflection coating as in claim 8 wherein the first layer furtherest from the substrate and the fourth layer adjacent the substrate have an index of refraction in the range of 1.35 to 1.62, the second layer has an index of refraction in the range of 2.00 to 2.30 and the third layer has an index of refraction in the range of 1.56 to 1.72.
Claim 11
Dependent Claim
39 words
A multi-layered anti-reflection coating as in claim 8 wherein the optical thickness of the third and fourth layers are as follows: 0.500 lambda o > N3d3 > 0.250 lambda o 0.250 lambda o > N4d4 > 0.060 lambda o.
Claim 12
Dependent Claim
39 words
A multi-layered anti-reflection coating as in claim 8 wherein the optical thickness of the third and fourth layers are as follows: 0.250 lambda o > N3d3 > 0.060 lambda o 0.500 lambda o > N4d4 > 0.250 lambda o.
Claim 13
Dependent Claim
39 words
A multi-layered anti-reflection coating as in claim 8 wherein the optical thickness of the third and fourth layers are as follows: 0.360 lambda o > N3d3 > 0.150 lambda o 0.470 lambda o > N4d4 > 0.060 lambda o.
Claim 14
Dependent Claim
16 words
multi-layered anti-reflection coating as in claim 8 wherein the first and fourth layers are magnesium fluoride.
Claim 15
Dependent Claim
30 words
A multi-layered anti-reflection coating as in claim 8 wherein the first and fourth coating layers are selected from the group consisting of MgF2, SiO2, ThF4, LaF2, Na3(AlF4), Al2O3, and CeF3.
Claim 16
Dependent Claim
27 words
A multi-layered anti-reflection coating as in claim 8 wherein the second coating layer is selected from the group consisting of CeO2, ZrO2, TiO2, Ta2O5, ZnS and ThO2.
Claim 17
Dependent Claim
35 words
A multi-layered anti-reflection coating as in claim 8 wherein the third coating layer is selected from the group consisting of Al2O3, MgO, CeF3, LaF3, NdF3, BeO, InO2, ThOH2 and a mixture of MgO and Al2O3.
Claim 18
Dependent Claim
75 words
A multi-layered anti-reflection coating as in claim 8 wherein the first and fourth coating layers are selected from the group consisting of MgF2, SiO2, ThF4, LaF2, Na3(AlF4), Al2O3, and CeF3; the second coating layer is selected from the group consisting of CeO2, ZrO2, TiO2, Ta2O5, ZnS and ThO2, and the third coating layer is selected from the group consisting of Al2O3, MgO, CeF3, LaF3, NdF3, BeO, InO2, ThOH2 and a mixture of MgO and Al2O3.
Claim 19
Dependent Claim
27 words
A multi-layered anti-reflection coating as in claim 8 wherein the substrate is a glass having an index of refraction Ns in the range of 1.42 to 1.72.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-24 | 1977-06-25 | 1977-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-24 | 1981-06-25 | 1981-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-24 | 1985-06-25 | 1985-12-25 | $7700.00 | Window Closed / Lapsed |