Flat image display device with filamentary cathode support structure

An image display device displays an image based on visible fluorescent radiation caused by electron beams emitted from a plurality of parallel spaced filamentary cathodes that extend over a substrate. A pair of support bars fixed to opposite sides of the substrate has a pair of spaced arrays of through holes defined therein, and supports a pair of spaced arrays of electrically conductive pins extending through through holes, with a plurality of electrically insulating bodies disposed around the electrically conductive pins and fitted in the through holes, respectively. Each of the filamentary cathodes has opposite ends secured to the support member and held against outer circumferential surfaces of one pair of electrically conductive pins of the spaced arrays.