| 摘要 |
1,246,234. Luminescent screens. PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd. 13 Feb., 1970 [18 Feb., 1969], No. 6998/70. Heading H1D. A method of manufacturing a colour c.r.t. screen comprises applying at least two luminescent substances of different emissions (e.g. red, green and blue strips with interposed opaque guard strips) to the window, wetting and coating with an organic solution and drying to form a film, applying a metal electron-permeable layer (e.g. A1) wetting by spraying a thickner solution of at least 1À2 centipoise, the solution then not penetrating and damaging the metal layer, drying, applying a photosensitive binder, drying exposing selected areas to radiation to form a latent indexing pattern thereon, treating to form an actual index pattern e.g. by applying a suspension and removing binder and suspension areas not required or alternatively removing binder areas not required and then selectively applying the suspension, and then baking. Also the indexing substance may be suspended in the photosensitive binder. At the exposed places the binder may be insoluble after prolonged exposure, or otherwise becomes sticky on wetting with solvent. The photosensitive layer basis may be an aqueous solution of polyvinyl alcohol and the organic material on the luminescent layer may be one or more methacrylates in toluene. During final baking the luminescent and indexing layer binders, organic film, and thickener may be removed. Preferably, the unexposed binder is removed by a thickener solution of at least 1À2 cp. viscosity and preferably is the same material as that on the metal layer e.g. organic binders, aqueous solutions of polyvinyl alcohol, and agar/agar. A wetting agent of a 1% aqueous solution of polyvinyl alcohol of 2À5 cp. is instanced, a suspension of cerium activated calcium aluminium silicate in an aqueous polyvinyl alcohol solution with ammonium bichromate sensitizer then being applied. All viscosities are measured at 20‹ C. |
