Patent ID: 8072127

Claim:
A thermionic electron emission device comprising: an insulating substrate; one or more grids located on the insulating substrate, wherein the one or more grids comprises: a first, second, third and fourth electrode down-leads located on the periphery of the one or more grids, wherein the first and the second electrode down-leads are parallel to each other, the third and fourth electrode down-leads are parallel to each other, and the first and the second electrode down-leads are insulated from the third and fourth electrode down-leads respectively; and a thermionic electron emission unit, the thermionic electron emission unit comprises a first electrode, a second electrode, and a thermionic electron emitter, the first electrode and the second electrode separately located and electrically connected to the first electrode down-lead and the third electrode down-lead respectively; wherein the thermionic electron emitter comprises a continuous carbon nanotube film structure having a first end electrically connected to the first electrode and a second end electrically connected to the second electrode, at least part of the thermionic electron emitter is suspended above the insulating substrate.