Transparent substrate with antireflection coating
AssigneeSaint-Gobain Vitrage
InventorsCharles-Edward Anderson, Philippe Macquart
Life of this patent
Estimating the term…
Abstract
The invention relates to a glass substrate having on at least one of its faces an antireflection coating formed by a stack of thin dielectric material layers having alternately high and low refractive indices. To prevent the modification of the optical properties of the coating in the case where the substrate is subject to a heat treatment such as tempering, bending or annealing, the layer or layers of the stack which are liable to deteriorate on contact with alkali ions such as sodium ions are separated form the substrate by at least one layer forming part of the antireflection coating and forming a "shield" with respect to the diffusion of alkali.
Claims31
A coated glass, comprising:
- (a) a glass substrate;
- (b) an antireflection coating on at least one surface of said substrate, wherein said coating is a stack of dielectric material layers having alternating high and low refractive indices, wherein at least one of said layers is a shield layer which prevents diffusion of alkali metal ions from said substrate through said shield layer, and
- wherein said antireflection coating comprises two successive sequences of high and low refractive index layers, a first sequence including said shield layer and a second sequence including a layer of niobium oxide, bismuth oxide or tungsten oxide, said first sequence and said second sequence also including a last outermost low refractive index layer comprising an aluminum-silicon oxide containing 10-12 wt % aluminum, based on silicon oxide.
Dependencies are inferred from the claim text.