Step gradient anti-iridescent coatings
First Claim
1. A substantially transparent glazing article comprising a substantially transparent substrate having a substantially transparent coating on a surface thereof, said coating comprising an optically functional layer having a refractive index higher than that of the substrate, and an anti-iridescence layer positioned mediate the substrate surface and the optically functional layer, the anti-iridescence layer being less thick than the optically functional layer and comprising a high refractive index zone directly on the substrate surface, having a refractive index substantially constant with distance from the substrate surface and higher than that of the substrate, and two gradient step zones over the high refractive index zone, the refractive index of each said gradient step zone being substantially constant with distance from the substrate surface, a first gradient step zone directly over the high refractive index zone having a refractive index lower than that of the high refractive index zone, and a second gradient step zone directly under the optical functional layer having a refractive index higher than that of the first gradient step zone.
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Accused Products
Abstract
A glazing article comprises a substrate bearing a substantially transparent coating comprising an optically functional layer and a thinner anti-iridescence layer undercoat mediate the optically functional layer and the substrate. The anti-iridescence layer eliminates or substantially reduces iridescence and, in addition, is readily designed to make the overall coating colorless or to provide a substantially uniform, muted color. The anti-iridescence layer comprises a high refractive index zone on the substrate, having a refractive index higher than that of the substrate. Multiple gradient step zones are stacked on the high refractive index zone, including a low refractive index zone. A second gradient step zone having a refractive index higher than that of the first gradient step zone is positioned on the low refractive index zone, such that the low refractive index zone is directly sandwiched between the two higher refractive index zones. Anti-iridescence is provided for a wide variety of optically functional layers without significant impairment of the optical performance thereof.
92 Citations
9 Claims
- 1. A substantially transparent glazing article comprising a substantially transparent substrate having a substantially transparent coating on a surface thereof, said coating comprising an optically functional layer having a refractive index higher than that of the substrate, and an anti-iridescence layer positioned mediate the substrate surface and the optically functional layer, the anti-iridescence layer being less thick than the optically functional layer and comprising a high refractive index zone directly on the substrate surface, having a refractive index substantially constant with distance from the substrate surface and higher than that of the substrate, and two gradient step zones over the high refractive index zone, the refractive index of each said gradient step zone being substantially constant with distance from the substrate surface, a first gradient step zone directly over the high refractive index zone having a refractive index lower than that of the high refractive index zone, and a second gradient step zone directly under the optical functional layer having a refractive index higher than that of the first gradient step zone.
Specification