Image orthicon

Claim 1

In an image orthicon tube for converting impinging optical images into video signals, the improvement comprising: an electron gun for emitting an electron scan beam at ambient temperatures, said gun including a field effect electron emitter having several million parallel emitting fibers per square centimeter of emitting surface area, with the emitting ends of said fibers being terminated in a plane across the emitter surface, an insulating oxide encompassing and separating said fibers, and a conductive backing plate adjoining first ends of said fibers for applying an electric potential thereto; a field effect emitter charge carrier matrix target sheet disposed in spatial alignment with said gun, said target including a thin sheet of metal-oxide composite having several million parallel metal fibers per square centimeter of surface area and disposed substantially coaxial and parallel with said electron gun emitting fibers, said metal fibers being disposed normal to the surfaces of said target sheet, an oxide insulator between respective metal fibers for enhancing face-to-face conduction through the sheet and retarding lateral conduction through the oxide, and a thin oxide coating on a first surface of said target sheet for providing secondary electron emission when stimulated by electron impact; and a photocathode disposed in alignment with said first surface of said target sheet, said photocathode emitting photoelectrons toward said target when stimulated by an input optical signal.