The electron gun has a cathode structure (40) with an electron emission section (43) for emitting a beam corresponding to red, green and blue fluorescent material and a focussing electrode (51) and end acceleration electrode (52) forming a main electron lens with electron beam through holes (51R...). The eccentric distance (S3) between the emission sections is shorter than the eccentric distance (S4) between the holes in the focussing electrode.
