Multi-layered anti-reflection coating
AssigneeMinolta Camera Kabushiki Kaisha
InventorsSadao Akatsuka, Hakuzo Tani
Life of this patent
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Abstract
A multi-layered anti-reflection coating for use with a plastic substrate is provided. The coating consists of four layers and has high durability. The first layer furthest from the substrate is made of SiO.sub.2 ; the second layer is made of a mixture of ZrO.sub.2 and TiO.sub.2 ; the third layer is made of ZrO.sub.2 ; and the fourth layer is made of SiO or SiO.sub.2. The optical thicknesses of the first to third layers are about 0.25.lambda. with respect to a design wavelength .lambda., respectively. However the optical thickness of the fourth layer is greater than that of the respective first to third layers and selected between 0.5.lambda. to 2.0.lambda..
Claims7
A multi-layered anti-reflection coating for use with a plastic substrate to reduce reflectance of light, comprising four layers;
- a first layer made of SiO.sub.2 furthest from the substrate;
- a second layer made of a mixture of ZrO.sub.2 and TiO.sub.2 ;
- a third layer made of ZrO.sub.2 ;
- and,
- a fourth layer made of a material selected from a group consisting of SiO and SiO.sub.2.
A multi-layered anti-reflection coating for use with a plastic substrate to reduce reflectance of light, comprising four layers;
- a first layer made of SiO.sub.2 furthest from the substrate and having an optical thickness of about 0.25.lambda.;
- a second layer made of a mixture of ZrO.sub.2 and TiO.sub.2 and having an optical thickness of about 0.25.lambda.;
- a third layer made of ZrO.sub.2 and having an optical thickness of about 0.25.lambda.;
- and,
- a fourth layer made of a material selecting a group consisting of SiO and SiO.sub.2 and having an optical thickness of 0.5.lambda.-2.0.lambda.;
- wherein .lambda. represents a design wavelength.
Dependencies are inferred from the claim text.