Patent ID: 6646393
Filing Date: 2003-11-11
Classification: H01J

Abstract:
A method of operating a cathode-ray tube (CRT) having an evacuated envelope having herein an electron gun for generating at least one electron beam, a faceplate panel having a luminescent screen with corresponding phosphor stripes on an interior surface thereof, wherein said CRT includes a focus mask, said focus mask having a plurality of spaced-apart first conductive electrodes and a plurality of spaced-apart second conductive electrodes oriented substantially perpendicular to the plurality of spaced-apart first conductive electrodes, said method including:directing said at least one electron beam from said electron gun in said envelope toward said focus mask and through slots between adjacent said spaced-apart first conductive electrodes; and applying a voltage differential between said plurality of spaced-apart first conductive electrodes and said plurality of spaced-apart second conductive electrodes that is large enough to operate said CRT in a positive tolerance mode in at least one location, wherein a lateral dimension of said at least one electron beam incident at said interior surface is less than a lateral dimension of said corresponding phosphor stripes.