Gradient-index anti-iridescent layer for transparent glazing article.

摘要

A substantially transparent glazing article has an optically functional coating (14) on a transparent substrate (12). The coating has an optically functional topcoat layer (18) and an anti-iridescence (20) layer between the topcoat and the substrate. The refractive index anti-iridescence layer (20) is (i) higher than the refractive index of the substrate in a first high refractive index zone (22) directly on the substrate surface, (ii) lower than that of the first high refractive index zone (22) in a low refractive index zone (24) directly on the first high refractive index zone (22), and (iii) higher than that of the low refractive index zone in a second high refractive index zone (24) directly on the low refractive index zone. The refractive index of the anti-iridescence layer (20) varies in at least one (24) of the zones substantially continuously with distance from the substrate surface (16). Contiguous zones may together form a single gradient index zone. The anti-iridescence layer (20) is less thick than the optically functional layer (18) and substantially reduces or eliminates iridescence without significantly impairing the optical functionality of the top coat layer.