Laminated glass plate with colored reflection and high solar transmittance, which is suitable for solar energy systems

摘要

A laminated and etched glazing unit having a substrate and a multi-layered interference filter each delimited by two main faces; the incident medium having a refractive index ninc=1, the substrate having a refractive index nsubstrate defined as: 1.45≤nsubstrate≤1.6 at 550 nm, and the exit medium being defined as follows 1.45≤nexit≤1.6 at 550 nm; and wherein the following requirements are met: The saturation of the colour is higher than 8 at near-normal angle of reflection, except for grey and brown; the visible reflectance is higher than 4%; the variation of the dominant wavelength MD of the dominant colour MD of the reflection is smaller than 15 nm for θr60°; and the total hemispherical solar transmittance is above 80%.