Electron-emitting device having focus coating that extends partway into focus openings

摘要

An electron-emitting device contains an electron focusing system (37 or 37A) formed with a base focusing structure (38 or 38A) and a focus coating (39 or 39A) that penetrates partway into a focus opening (40) extending through the base focusing structure above an electron- emissive element (24). The focus coating is normally of lower resistivity than the base focusing structure and thereby provides most of the focus control over electrons emitted by the electron-emissive element. The focus coating is typically formed by an angled deposition technique.