providing luminescent sheets of exceptionally high intrinsic brilliance

luminescent sheets are known wherein a coating of finely divided phosphor or luminescent material is provided on the interior surface of an envelope, which material upon excitation by corpuscular or radiant energy, becomes luminescent and fluoresces with a soft luminescent glow. The intrinsic brilliance of such devices is quite low and they are not adapted for the production of light of high intrinsic brilliance. A further disadvantage of such sheets resides in the fact that the luminescent material which is in finely divided powdered form absorbs as well as diffuses a considerable proportion of the emitted light.

Objects of our include providing luminescent sheets of exceptionally high intrinsic brilliance; sheets of high intrinsic brillance having a wide range of colors or band spectrum emission within the ultra violet, visible and infra red portions of the spectrum; sheets of exceptionally aigh intrinsic brilliance which operate at low 2 temperatures whereby the use of glow in the dark dye cooling means such as circulating air or water is avoided, and visible radiation luminescent lamps excited by indisible luminescent radiation. Further objects of my invention include the provision of sheets of the type described having high intrinsic brilliance without rapid destruction of the luminescent material and lamps wherein a combination of nondirectional with highly directional light propagating properties may be obtained in a single sheets 3 and wherein the single sheets is capable of producing a wide variety of colors. Still further objects of my invention are to provide luminescent lamps having high output energy levels within both the visible and invisible portions of the 4 spectrum and fluorescent screens of novel type in combination with lamps producing ultra violet radiation whereby any desired colored light may be obtained.