Patent ID: 7893605

Claim:
A back gated field emission device comprising: a substantially planar conducting material forming a gate electrode; an electric insulating layer juxtaposed to said gate electrode; a plurality of parallel conductive stripes having length and forming cathodes disposed on and having a base contacting the insulating layer with each of the cathode stripes having a crest at a surface opposite a base contacting the insulating layer, wherein the insulating layer is between said gate and said cathodes; at least one conductive anode where the electrons are collected, where the anode is situated on the opposite side of the cathodes contacting the insulating layer and beyond the crest of the cathodes; where the arrangement of the gate, the insulating layer, the cathodes and the at least one anode results in a back gated configuration; wherein said cathodes are positioned in a substantially parallel relation with said gate electrode, the cathodes each having a cross-section taken normal to said length; wherein a cross-sectional width, divided by a cross-sectional height of a rectangle that minimally and fully encloses the cross-section of said cathodes is less than approximately 2, where one edge of the rectangle contacts the crest of the cathode and is parallel to the plane of the gate electrode said cross-section being substantially uniform along the length of the cathode stripes; wherein the cathode stripes are substantially prismatic with any number of longitudinal faces joined at edges; where at least a portion of the edges are rounded; and a strip of low effective work-function material disposed along the crest of the cathodes facing said anode.