▎ 摘　　要

NOVELTY - The field emission device has an emitter (30a) with a cathode electrode (10a) and an electron emission source (20a) supported by the cathode electrode, and an insulating spacer around the emitter. The insulating spacer forms an opening that is a path of electrons emitted from electron emission source. A gate electrode has a graphene sheet covering the opening and an electrode unit set around the opening. The graphene sheet is connected to electrode unit. The graphene sheet is a single-layered or multi-layered graphene thin film (21a). USE - Field emission device for electronic apparatus. Uses include but are not limited to X-ray generator, field emission display, back light unit of lighting apparatus, X-ray apparatus for generating three-dimensional image e.g. digital breast tomo-synthesis for diagnosing breast cancer, display apparatus such as LCD. ADVANTAGE - Improves field emission efficiency since leakage current that leaks through the electrode unit is reduced and electric field strengthening effect is generally maximized. The traveling straightness of the electrons is improved. Increases electron emission density since electric field strengthening effect when electric field is concentrated on electron emission source increases as the aspect ratio of electron emission source is larger. Obtains excellent electrical and thermal interface characteristics between the graphene thin films and cathode electrode. Prevents degradation of field emission efficiency due to electrical and thermal factors. The loss in field emission efficiency due to electrical and thermal factors is further reduced since contact area between the graphene thin films and cathode electrode is increased. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method of manufacturing a gate electrode. DESCRIPTION OF DRAWING(S) - The drawing shows a perspective view of the manufactured emitter. Cathode electrode (10a) Electron emission source (20a) Graphene thin film (21a) First portion (22) Emitter (30a)