Electron-emitting device having large control openings in specified, typically centered, relationship to focus openings

摘要

An electron-emitting device contains an emitter electrode (12), a group of sets of electron-emitting elements (24), a group of control electrodes (28), and a focusing system (37) for focusing electrons emitted by the electron-emissive elements. The sets of electron-emissive elements are arranged generally in a line extending in a specified direction. Each control electrode has a main portion (30) and a gate portion (32). the electron-emissive elements are exposed through gate openings (36) in the gate portion. The main portion of each control electrode crosses over the emitter electrode and has a large control opening (34) which laterally circumscribes one of the sets of electron-emissive elements. The focusing system has a group of focus openings (40) located respectively above the control openings. Each control opening is largely centered on, or/and is no more than 50% as large as, the corresponding focus opening in the specified direction.