SHADOW MASK FOR CATHODE RAY TUBE AND ITS MANUFACTURING METHOD

PURPOSE: A shadow mask having a curved surface intensity is provided to increase the mechanical strength of the shadow mask and to enhance the landing accuracy. CONSTITUTION: The cathode ray tubes comprise a phosphor screen formed on an inner surface plate of a panel portion of an evacuated envelope, a shadow mask having a multiplicity of electron beam apertures and spaced from the phosphor screen within the panel portion, an electron gun of the in-line type housed within a neck portion of the evacuated envelope, and a deflection yoke mounted around a funnel portion of the evacuated envelope. Three electron beams emitted from the electron gun are deflected by the deflection yoke and thereafter are projected onto picture elements of the corresponding colors of the phosphor screen through the electron beam apertures of the shadow mask to display a desired color image on the phosphor screen. The shadow mask manufacturing is a processes of forming a phosphor screen. The processes comprise an annealing process, a paste composition process to make ceramic coating material, a screen printing process, a drying process, a shaping process, and a blackening furnace process.