Sigma Patent - Nano Crystal Coating like Canon and Nikon

Sigma Working on advance lens Anti Reflection coating for lenses. For the lens coating, Sigma will going to use mesoporous silica material similar to “Nano Crystal Coat” of NIKON and “Air Sphere Coating” of CANON.

6 layer multilayer coating diagram shared by Sigam patent details

Patent Details of Sigma Anti Reflection Coating

PROBLEM TO BE SOLVED: To provide an antireflection film having low reflectance in a wide wavelength range of visible light to a substrate having various productivity and various refractive indices.

SOLUTION: This antireflection film is formed by laminating in order a first layer, a second layer, a third layer, a fourth layer, a fifth layer and a sixth layer from the side of the substrate in this order, A high refractive index material having an optical film thickness of one layer of 0.045λ or more and 0.971λ or less, the second layer has a low refractive index material with an optical thickness of 0.025λ or more and 0.166λ or less, The third layer has a high refractive index material with an optical thickness of 0.038λ or more and 0.375λ or less and the fourth layer has a low refractive index material with an optical thickness of 0.048λ or more and 0.152λ or less , The optical film thickness of the fifth layer is 0.045λ or more and 0.119λ or less, the optical film thickness of the sixth layer is 0.228λ or more and 0.331λ or less, and the refractive index is And is an ultra-low refractive index material having a refractive index of 1.10 or more and 1.30 or less.

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