Patent ID: 6238781
Filing Date: 2001-05-29
Classification: B32B,C03C,Y10T

Abstract:
A coated transparent substrate, comprising:a transparent substrate including alkali metal ions; andan antireflection coating on at least one surface of said substrate, whereinsaid coating is a stack of dielectric material layers having alternating high and low refractive indices,at least one of said layers is a shield layer which prevents diffusion of said alkali metal ions from said substrate through said shield layer, andsaid shield layer is a high refractive index dielectric material layer selected from the group consisting of silicon nitride and aluminum nitride, andsaid coated transparent substrate has a light reflection R.sub.L of at most 2% and a blue or blue-green color in reflection, with a variation of R.sub.L of at most 0.3% and variations of a* and b* in reflection of at most 2.0 after heating.