Abstract: A method of operating a positive tolerance color cathode-ray tube (CRT) having an evacuated envelope with an electron gun and a focus mask therein for generating at least one electron beam. The envelope further includes a faceplate panel having a luminescent screen of color-emitting phosphor stripes on an interior surface thereof. The color-emitting phosphor stripes each have a width slightly smaller than one-third of the screen pitch, such that large clipping and leaving tolerances may be achieved therewith. The focus mask, having a plurality of spaced-apart first conductive electrodes, is located adjacent to an effective picture area of the screen. The spacing between the first conductive electrodes defines a plurality of slots substantially parallel to the color-emitting phosphor stripes on the screen. Each of the first conductive electrodes has a substantially continuous insulating material layer formed on a screen facing side thereof.

Abstract: The present invention relates to a method of electrophotographically manufacturing a phosphor screen 22 comprising a multiplicity of color-emitting screen elements arranged in color groups on an interior surface of a faceplate panel 12 of a color CRT 10. The multiplicity of screen elements is exposed to a source 35 of UV radiation to stimulate the screen elements to emission. The emission from the screen elements is utilized to determine, on a pixel-by-pixel basis, a first emission characteristic of each color group of screen elements. Then, a subsequent manufacturing step (58, 62) is performed that affects the screen elements, and the multiplicity of screen elements is re-exposed to the source of UV radiation to stimulate the screen elements to emission. The resultant emission is utilized to determine, on a pixel-by-pixel basis, a second emission characteristic from each color group of screen elements.

Abstract: The invention relates to a method of determining the quality of an aluminized, luminescent screen 22 for a CRT 10. The luminescent screen 22 is disposed on an interior surface of a faceplate panel 12 with an aluminum layer 23 overlying the screen. The method includes the steps of: exposing the aluminum layer to ultraviolet radiation; and measuring the luminescence emitted by the screen through the aluminum layer.