Patent ID: 7652418

Claim:
An electron emission device comprising: a first substrate; a cathode electrode disposed on the first substrate; a gate electrode electrically insulated from the cathode electrode; an insulating layer disposed between the cathode electrode and the gate electrode to insulate the cathode electrode from the gate electrode; and an electron emission source comprising a plurality of carbon nanotubes (CNTs) that each contact the cathode electrode at one end and comprise a tip at another end separated from the gate electrode by a distance, wherein the distance between the gate electrode and the tip of each of the CNTs is uniform, wherein the CNTs are vertically grown, wherein the lengths of CNTs at the center of the electron emission source are longer than the lengths of CNTs on edges of the electron emission source, and wherein the diameters of the CNTs on the edges of the electron emission source are greater than the diameters of the CNTs at the center of the electron emission source.