Art of making color-phosphor screens of the mosaic variety

Claim 1

IN THAT METHOD OF MAKING A COLOR-PHOSPHOR SCREEN OF THE MOSAIC VARIETY WHICH CONSISTS ESSENTIALLY OF THE FOLLOWING STEPS: (1) APPLYING TO A FOUNDATION SURFACE A SLURRY LAYER COMPRISING PHOSPHOR PARTICLES OF ONE COLOR CONTAINED IN A PHOTOSENSITIZED ORGANIC GEL, (II) DRYING SAID LAYER SELECTED FROM THE GROUP CONSISTING OF POLYVINYL ALCOHOL, FISH GLUE, AND ALBUMEN, (III) EXPOSING SAID PHOSPHOR-CONTAINNG PHOTOSENSITIVE LAYER TO ACTINIC RAYS THROUGH AN OPTICAL STENCIL CONTAINING A PATTERN OF TRANSPARENT AREAS CORRESPONDING TO THE ELEMENTARY AREAS OF A SINGLE COLOR IN THE DESIRED MOSAIC, WHEREBY PHOTOGRAPHICALLY TO RECORD THE PATTEN OF ELEMENTARY AREAS OF THAT COLOR UPON SAID FOUNDATION SURFACE, (IV) WASHING SAID SURFACE TO DEVELOP THE PHOTOGRAPH THEREON. (V) DRYING SAID PHOSPHOR-CONTAINING PHTOGRAPH, (VI) REPEATING THE PRECEDING STEPS FOR EACH OF THE OTHER COLORS WITH THE SOURCE OF ACTINIC RAYS DISPOSED AT APPROPRIATELY DIFFERENT POSITIONS WITH RESPECT TO SAID STENCIL, THE IMPROVEMENT IN SAID METHOD WHICH COMPRISES: THE USE IN AT LEAST ONE OF THE OTHER COLOR SLURRY LAYERS OF A MATERIAL SELECTED FORM THE GROUP CONSISTING OF GLYCEROL AND GLYCOLS, AND THE DRYING OF SAID ONE OF THE OTHER COLOR SLURRY LAYERS WITHOUT PARCHING IT, WHEREBY TO MINIMIZE INTERMINGLING OF THE COLOR-PHOSPHOR IN SAID LAST APPLIED SLURRY-LAYER WITH THE COLOR-PHOSPHOR CONATINED IN ANY OF SAID PREVIOUSLY DEVELOPED ELEMENTARY MOSAIC AREAS.