Patent ID: 8242676

Claim:
A field emission device comprising: a substrate; an electrode positioned on the substrate; a seed layer positioned on the electrode; a mask layer positioned on the seed layer and comprising one or more openings; and a plurality of nanostructures positioned on the seed layer via the openings and formed to extend radially, wherein the one or more openings are formed to be spaced apart from each other with a certain pattern, wherein the plurality of nanostructures are configured to emit electrons upon receiving an electric field by applying a voltage from the electrode and the seed layer, wherein the plurality of nanostructures are regularly arranged along an x-axis direction and a y-axis direction, and among the plurality of nanostructures neighboring nanostructures have substantially the same distance therebetween, wherein end portions of one or more nanostructures, among the plurality of nanostructures, have a pointed shape, wherein the end portion of the nanostructure refers to a region from a boundary point at which the diameter of the nanostructure, which is maintained to be substantially the same, starts to become smaller to the tip of the nanostructure, wherein the end portions have the shape of an isosceles triangle, and a ratio of the height to the length of the base of the isosceles triangle is 2 to 4, and wherein a ratio of the length of one or more nanostructures, among the plurality of nanostructures, obtained by cutting the one or more nanostructures in a direction perpendicular to a surface of the substrate to the length thereof obtained by cutting in a direction parallel to the surface of the substrate is 10 or larger.