US Patent 7355329 - CNT field emission lamp bulb

http://www.freepatentsonline.com/7355329.html

This patent teaches a light bulb based on field emission from carbon nanotubes formed on the outer surface of a base of the lamp head. Claim 1 reads:

1. A field emission lamp comprising:

a bulb being vacuum sealed and having an inner surface;

a lamp head mated with the bulb; an electron emitting cathode positioned in the bulb, wherein the electron emitting cathode comprises a plurality of electron emitters, and a base body having an outer surface, the base body is comprised of metallic material, and the electron emitters are carbon nanotubes and are formed on the outer surface of the base body;

an anode layer formed on the inner surface of the bulb; a fluorescence layer formed on the anode layer; an anode electrode located at the lamp head and electrically connected with the anode layer; and

a cathode electrode located at the lamp head and electrically connected with the electron emitting cathode.

One relevant patent that wasn't considered during prosecution is US Patent 6573643 which teaches a field emission light source using a carbon coating which includes carbon nanotubes (see column 9, lines 20-30).