Patent ID: 7812511
Filing Date: 2010-10-12
Classification: H01J

Abstract:
1. A field emission illumination device, comprising: a sealed tubular body having a light-permeable portion; an anode layer formed on an inner surface of the light-permeable portion of the sealed tubular body; a fluorescence layer formed on the anode layer; an electron emitting cathode positioned in the sealed tubular body, the electron emitting cathode comprising at least one un-twisted carbon nanotube yarn, wherein the at least one un-twisted carbon nanotube yarn forms a free-standing structure to longitudinally extend from one end of the sealed tubular body to the other end of the sealed tubular body; an anode electrode that extends through the light-permeable portion into the tubular body and is in electrical contact with the anode layer; and at least one cathode electrode disposed outside the tubular body and electrically connected with the electron emitting cathode; wherein the at least one un-twisted carbon nanotube yarn comprises of a plurality of carbon nanotubes substantially parallel to one another and bundled together by Van der Waals interactions.