| 摘要 |
<p>An illuminated colour-patterned surface for decorative purposes, e.g. as wall cladding lampshade illuminated sign, is so arranged that the colours of the pattern are dependent upon the direction of observation; the surface comprises a number of successive layers of translucent material, comprising a light scattering layer, two linear polarising layers and >=1 doubly-refracting layer, through which the light passes in succession in the sequence scattering layer, polarising layer, doubly refracting layer, second polarising layer etc. The light scattering layer may be of low pressure polyethylene or PVC, and the doubly refracting layers of cellular glass, polypropylene polyamide or polyethylen terephthalate sheet giving a varied pattern either due to inhomogeneity of the material or due to being folded without cracking or kinking.</p> |
