Patent ID: 7883776

Claim:
A transparent article comprising a transparent substrate; an optical coating comprising one or more layers on the substrate, where the one or more layers include furthest from the substrate a homogeneous outermost layer comprising amorphous silicon nitride; and a protective coating on the outermost layer, wherein the protective coating consists of a scratch propagation blocker layer on the outermost layer, and a layer consisting essentially of carbon on the scratch propagation blocker layer; and the scratch propagation blocker layer is a homogeneous layer comprising a material selected from the group consisting of Ti, Zr, Cr, Nb, Hf, and Ta; oxides of Ti, Zr, Cr, Nb, Hf, and Ta; nitrides of Ti, Zr, Cr, Nb, Hf, and Ta; oxynitrides of Ti, Zr, Cr, Nb, Hf, and Ta; and mixtures thereof.