Jaeger, S.S.JaegerNeumann, F.F.Neumann2022-03-082022-03-081998https://publica.fraunhofer.de/handle/publica/303957A projection mask consists of a transparent substrate (1) having its optically active surface at least partially covered with one or more organic dyestuff molecule-containing coloured layers (3) formed of vacuum vapour deposited colour pigments or their mixtures, dyestuff/dielectric composites, dyestuff/dielectric layer stacks or multilayer systems or of sol-gel layers. Preferably, the dyestuff pigments, contained in the layer(s), are temperature resistant at up to 250 deg. C. Also claimed is production of the above projection mask, in which the organic dyestuff molecules are applied by vacuum vapour deposition or as a sol-gel layer. USE - For projecting images such as company logos and geometrical figures onto walls, ceilings, etc. ADVANTAGE - The mask permits projection of coloured or multi-coloured images, has satisfactory temperature and light stability (allowing permanent use at high light intensities and temperatures) and provides a high colour saturation, combined with high tran sparency and homogeneity (low scattering).de608667patent1996-19642001