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US 6,280,848 B1Granted
Antireflection coating
AssigneeMinolta Co., Ltd.
InventorsMasaru Okumura, Hakuzo Tani
Life of this patent
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Abstract
Four and five-layer antireflection coatings are disclosed suitable for use on optical parts such as lenses and prisms in which layers of thin films are formed on the surfaces of the optical parts by a process such as vacuum evaporation. By selecting the materials for the layers based on the refractive index of the materials, as well as based on the refractive index of the substrate, reflectance of the s-polarized component of incident light can be reduced over a large range of incident angle up to a range of approximately 45 degrees.
Claims14
An antireflection coating for a substrate comprising:
- a first layer for placement on said substrate either directly or through another layer, said first layer having a thickness d1 and a refractive index n1;
- a second layer in contact with said first layer, said second layer having a thickness d2 and a refractive index n2;
- a third layer in contact with said second layer, said third layer having a thickness d3 and a refractive index n3;
- and
- a fourth layer in contact with said third layer, said fourth layer having a thickness d4 and a refractive index n4;
- wherein, for a dominant wavelength λ0, the following relationships are satisfied:
- n3>n2>n1>n4;
- 0<(n1*d1)≦0.75*λ0;
- 0.20*λ0≦(n2*d2)≦0.43*λ0;
- 0.07*λ0≦(n3*d3)≦1.10*λ0;
- and
- 0.28*λ0≦(n4*d4)≦0.35*λ0.
9 more elements
An antireflection coating for a substrate comprising:
- a first layer for placement on said substrate either directly or through another layer, said first layer having a thickness d1 and a refractive index n1;
- a second layer in contact with said first layer, said second layer having a thickness d2 and a refractive index n2;
- a third layer in contact with said second layer, said third layer having a thickness d3 and a refractive index n3;
- a fourth layer in contact with said third layer, said fourth layer having a thickness d4 and a refractive index n4;
- and
- a fifth layer in contact with said fourth layer, said fifth layer having a thickness d5 and a refractive index n5
- wherein, for a dominant wavelength λ0, the following relationships are satisfied:
- n2 or n3≦1.56;
- n4≧n2>n1≧n5;
- n2>n3;
- 0<(n1*d1)≦0.06*λ0;
- 0.03*λ0≦(n2*d2)≦0.15*λ0;
- 0.02*λ0≦(n3*d3)≦0.19*λ0;
- 0.09*λ0≦(n4*d4)≦1.30*λ0;
- and
- 0.24*λ0≦(n5*d5)≦0.36*λ0.
13 more elements
An antireflection coating for a substrate comprising:
- a first layer for placement on said substrate either directly or through another layer, said first layer having a thickness d1 and a refractive index n1;
- a second layer in contact with said first layer, said second layer having a thickness d2 and a refractive index n2;
- a third layer in contact with said second layer, said third layer having a thickness d3 and a refractive index n3;
- a fourth layer in contact with said third layer, said fourth layer having a thickness d4 and a refractive index n4;
- a fifth layer in contact with said fourth layer, said fifth layer having a thickness d5 and a refractive index n5
- wherein, for a dominant wavelength λ0, the following relationships are satisfied;
- n2 or n3≦1.56;
- n4≧n2>n1≧n5;
- n2>n3;
- 1.50≦ns≦1.85;
- 1.35≦n1≦1.80;
- 2.00≦n2≦2.60;
- 1.35≦n3≦1.80;
- 2.00≦n4≦2.60;
- and
- 1.38≦n5≦1.48
- 0.20≦(n1*d1)≦1.25*λ0;
- 0.03*λ0≦(n2*d2)≦1.15*λ0;
- 0.02*λ0≦(n3*d3)≦1.19*λ0;
- 0.09*λ0≦(n4*d4)≦1.30*λ0;
- and
- 0.24*λ0≦(n5*d5)≦0.36*λ0.
19 more elements
An antireflection coating for a substrate comprising:
- a laminate of at least four layers, a first of said four layers for contact with said substrate either directly or through another layer, adjacent layers of said at least four layers being comprised of different materials;
- wherein said at least four layers are configured so that, when said laminate is in contact with said substrate, either directly or through another layer, for light incident on said laminate, from a side opposing said substrate, at an angle of incidence of approximately 45 degrees, an amount of s-polarized light reflected therefrom, as a percentage of an amount of s-polarized light incident thereon, is lower than an amount of p-polarized light reflected therefrom, as a percentage of an amount of p-polarized light incident thereon.
A process for forming an anti-reflection coating on an article, comprising the steps of:
- disposing an anti-reflection coating including a plurality of layers on said article, said disposing step including the steps of:
- forming a first layer on said article either directly or through another layer;
- forming a second layer on said first layer;
- forming a third layer on said second layer;
- and
- forming a fourth layer on said third layer, adjacent layers of said first, second, third and fourth layers being composed of different materials;
- wherein said plurality of layers are configured so that, for light incident on said anti-reflection coating, from a side op-posing said article, at an angle of incidence of approximately 45 degrees, an amount of s-polarized light reflected therefrom, as a percentage of an amount of s-polarized light incident thereon, is lower than an amount of p-polarized light reflected therefrom, as a percentage of an amount of p-polarized light incident thereon.
4 more elements
An article comprising:
- a substrate;
- a first layer arranged on said substrate either directly or through another layer, said first layer having a thickness d1 and a refractive index n1;
- a second layer arranged on said first layer, said second layer having a thickness d2 and a refractive index n2;
- a third layer arranged on said second layer, said third layer having a thickness d3 and a refractive index n3;
- and
- a fourth layer arranged on said third layer, said fourth layer having a thickness d4 and a refractive index n4;
- wherein, for a dominant wavelength λ0, the following relationships are satisfied:
- n3>n2>n1≧n4;
- 0<(n1*d1)≦0.75*λ0;
- 0.20*λ0≦(n2*d2)≦0.43*λ0;
- 0.07*λ0≦(n3*d3)≦1.10*λ0;
- and
- 0.28*λ0≦(n4*d4)≦0.35*λ0.
10 more elements
Dependencies are inferred from the claim text.