US4387960A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multi-layer anti-reflection coating
Assignee: Minolta Co Ltd
•
Filing: 1981-03-17
•
Granted: 1983-06-14
•
Expires: 2001-03-17
Abstract
Abstract A multi-layer anti-reflection coating is provided having four layers. The design can be defined by the following parameters: N1d1 SIMILAR 0.25 lambda o; N2d2 SIMILAR 0.
Inventors
- 👤 Hakuzo Tani
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:36
CPC Classifications
G; G02; G02B; G02B1/00; G02B1/10; G02B1/11; G02B1/113; G02B1/115
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
160 words
A multi-layered anti-reflection coating for use with a glass substrate to reduce reflectance of light comprising four layers, the first layer furthest from the substrate having a refractive index, N 1 and an optical thickness N 1 d 1 , the second layer having a refractive index N 2 and an optical thickness N 2 d 2 , the third layer having a refractive index N 3 and an optical thickness N 3 d 3 and the fourth layer closest to the substrate having a refractive index N 4 and an optical thickness N 4 d 4 , wherein the refractive indices and the optical thicknesses are related as follows with respect to a preselected design wavelength, λo: N 1 d 1 ≅0.25 λo; N 2 d 2 ≅0.50 λo; 0.50 λo≦N 3 d 3 ≦0.75 λo; N 4 d 4 <0.25 λo; 1.35≦N 1 ≦1.62; 1.90≦N 2 ≦2.30; 1.90≦N 4 ≦2.30; 1.56≦N 3 ≦1.80; and N 1 <N 3
Claim 2
Dependent Claim
160 words
A multi-layered anti-reflection coating for use with a glass substrate to reduce reflectance of light comprising four layers, the first layer furthest from the substrate having a refractive index, N 1 and an optical thickness N 1 d 1 , the second layer having a refractive index N 2 and an optical thickness N 2 d 2 , the third layer having a refractive index N 3 and an optical thickness N 3 d 3 and the fourth layer closest to the substrate having a refractive index N 4 and an optical thickness N 4 d 4 , wherein the refractive indices and the optical thicknesses are related as follows with respect to a preselected design wavelength, λo: N 1 d 1 ≅0.25 λo; N 2 d 2 ≅0.50 λo; 0.50 λo≦N 3 d 3 ≦0.75 λo; N 4 d 4 <0.25 λo; 1.35≦N 1 ≦1.62; 1.90≦N 2 ≦2.30; 1.90≦N 4 ≦2.30; 1.56≦N 3 ≦1.80; and N 1 <N 3
Claim 3
Dependent Claim
34 words
A multi-layered anti-reflection coating as in claim 1 wherein the first layer is selected from a group consisting of MgF 2 , LaF 2 , Na 3 (AlF 4 ) and SiO 2 .
Claim 4
Dependent Claim
44 words
A multi-layered anti-reflection coating as in claim 1 wherein the second and fourth layers are selected from a group consisting of ZrO 2 , TiO 2 , CeO 2 , HfO 2 , ZnS and a mixture of ZrO 2 and TiO 2 .
Claim 5
Dependent Claim
38 words
A multi-layered anti-reflection coating as in claim 1 wherein the third layer is selected from a group consisting of Al 2 O 3 , CeF 3 , Y 2 O 3 , Gd 2 O 3 and MgO.
Claim 6
Dependent Claim
98 words
A multi-layered anti-reflection coating for use with a substrate to reduce reflectance comprising four layers of material, each layer respectively having an optical thickness with respect to a preselected design wavelength λo, and the relationship between the indices of refractions between the substrate, N s , and the layers are as follows: N 4 , N 2 >N s , N 3 >N 1 wherein N refers to the index of refraction and the subnumber refers to the layer sequentially numbered from the layer farthest from the substrate, N 1 , to the adjacent layer N 4 .
Claim 7
Dependent Claim
98 words
A multi-layered anti-reflection coating for use with a substrate to reduce reflectance comprising four layers of material, each layer respectively having an optical thickness with respect to a preselected design wavelength λo, and the relationship between the indices of refractions between the substrate, N s , and the layers are as follows: N 4 , N 2 >N s , N 3 >N 1 wherein N refers to the index of refraction and the subnumber refers to the layer sequentially numbered from the layer farthest from the substrate, N 1 , to the adjacent layer N 4 .
Claim 8
Dependent Claim
14 words
The invention of claim 5 wherein N 4 is equal to N 2 .
Claim 9
Dependent Claim
25 words
The invention of claim 5 wherein the optical thickness, N 4 d 4 , of the layer adjacent the substrate is less than 0.040 λo.
Claim 10
Dependent Claim
32 words
The invention of claim 7 wherein the optical thickness, N 4 d 4 , of the layer adjacent the substrate is within the following range: 0.040 λo>N 4 d 4 >0.010 λo
Claim 11
Dependent Claim
32 words
The invention of claim 8 wherein the optical thickness, N 3 d 3 , of the third layer is equal or greater than 0.500 λo and equal or less than 0.750 λo.
Claim 12
Dependent Claim
23 words
The invention of claim 5 wherein the substrate is a glass having an index of refraction in the range of 1.4 to 1.9.
Claim 13
Dependent Claim
31 words
The invention of claim 5 wherein the first layer is selected from a group consisting of MgF 2 , LaF 2 , Na 3 (AlF 4 ) and SiO 2 .
Claim 14
Dependent Claim
41 words
The invention of claim 5, wherein the second and fourth layers are selected from a group consisting of ZrO 2 , TiO 2 , CeO 2 , HfO 2 , ZnS and a mixture of ZrO 2 and TiO 2 .
Claim 15
Dependent Claim
35 words
The invention of claim 5 wherein the third layer is selected from a group consisting of Al 2 O 3 , CeF 3 , Y 2 O 3 , Gd 2 O 3 and MgO.
Claim 16
Dependent Claim
32 words
The invention of claim 5 wherein the optical thickness, N 3 d 3 , of the third layer is equal or greater than 0.500 λo and equal or less than 0.750 λo.
Claim 17
Dependent Claim
25 words
The invention of claim 5 wherein the refractive indices are as follows: 1.35≦N 1 ≦1.62; 1.90 ≦N 2 ≦2.30; 1.90≦N 4 ≦2.30; 1.56≦N 3 ≦1.80.
Claim 18
Dependent Claim
14 words
The invention of claim 15 wherein N 3 is greater than N 1 .
Claim 19
Dependent Claim
37 words
The invention of claim 15 wherein the optical thicknesses are as follows: N 1 d 1 ≅0.250 λo; N 2 d 2 ≅0.500 λo; 0.500 λo≦N 3 d 3 ≦0.750 λo; N 4 d 4 <0.250 λo.
Claim 20
Dependent Claim
89 words
A multi-layered anti-reflection coating for use with a substrate to reduce reflectance comprising four layers of material, each layer respectively having an effective optical thickness, Nd, of a preselected design wavelength λo as follows: N 1 d 1 ≅0.250 λo; N 2 d 2 ≅0.500 λo; 0.500 λo≦N 3 d 3 ≦0.750 λo; N 4 d 4 <0.040 λo. wherein the subnumber refers to the layer sequentially numbered from the layer farthest from the substrate, N 1 d 1 , to the adjacent layer N 4 d 4 .
Claim 21
Dependent Claim
89 words
A multi-layered anti-reflection coating for use with a substrate to reduce reflectance comprising four layers of material, each layer respectively having an effective optical thickness, Nd, of a preselected design wavelength λo as follows: N 1 d 1 ≅0.250 λo; N 2 d 2 ≅0.500 λo; 0.500 λo≦N 3 d 3 ≦0.750 λo; N 4 d 4 <0.040 λo. wherein the subnumber refers to the layer sequentially numbered from the layer farthest from the substrate, N 1 d 1 , to the adjacent layer N 4 d 4 .
Claim 22
Dependent Claim
32 words
The invention of claim 18 wherein the optical thickness, N 4 d 4 , of the layer adjacent the substrate is within the following range: 0.040 λo>N 4 d 4 >0.010 λo.
Claim 23
Dependent Claim
69 words
The invention of claim 19 wherein the relationship between the indices of refraction are as follows: N 4 , N 2 >N s , N 3 >N 1 ; wherein N refers to the index of refraction and the subnumber refers to the layer sequentially numbered from the layer farthest from the substrate, N 1 , to the adjacent layer N 4 with N s referring to the substrate.
Claim 24
Dependent Claim
24 words
The invention of claim 20 wherein the refractive indices are as follows: 1.35≦N 1 ≦1.62; 1.90≦N 2 ≦2.30; 1.90≦N 4 ≦2.30; 1.56≦N 3 ≦1.80.
Claim 25
Dependent Claim
31 words
The invention of claim 18 wherein the first layer is selected from a group consisting of MgF 2 , LaF 2 , Na 3 (AlF 4 ) and SiO 2 .
Claim 26
Dependent Claim
41 words
The invention of claim 18 wherein the second and fourth layers are selected from a group consisting of ZrO 2 , TiO 2 , CeO 2 , HfO 2 , ZnS and a mixture of ZrO 2 and TiO 2 .
Claim 27
Dependent Claim
30 words
The invention of claim 18 wherein the third layer is selected from a group consisting of Al 2 O 3 , CeF 3 , Y 2 O 3 and MgO.
References Cited (Backward Citations)
US3235397A
Cited
US3432225A
Cited
US3463574A
Cited
US3604784A
Cited
US3565509A
Cited
US3781090A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-06-13 | 1986-12-13 | 1987-06-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-06-13 | 1990-12-13 | 1991-06-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-06-13 | 1994-12-13 | 1995-06-14 | $7700.00 | Window Closed / Lapsed |