TRANSPARENT LAYERED ELEMENT WITH DIRECTIONAL DIFFUSE REFLECTION

Abstract

This transparent layered element (1) comprises: two transparent outer layers having substantially the same refractive index and each having a smooth outer principal surface (2a, 4a), and a central layer interposed between the outer layers, the central layer comprising at least one transparent layer having a refractive index different from that of the outer layers or a metallic layer. All contact surfaces between two adjacent layers of the layered element (1) where one of the two layers is a metallic layer, or which are two transparent layers with different refractive indices, are textured and parallel to each other, the diffuse light reflection of the layered element (1) on the side of at least one of the outer layers having at least one maximum in a direction distinct from the direction of specular reflection.Furthermore, the surface of the layered element (1) is divided into a plurality of pixels of the same dimension, each pixel having at least one side of length less than or equal to 500 µm, the texture of each textured contact surface within each pixel having a distribution of slopes fpix(θx, θy) having a correlation coefficient ݎ with the distribution of slopes ftot(θx, θy) of the texture of the total textured contact surface, the layered element being such that, for a sample of n pixels, the mean of the correlation coefficients r (fpix, ftot) of each pixel in the sample is greater than or equal to 0.8.