US Patent 7319288 - Flat carbon nanotube array

http://www.freepatentsonline.com/7319288.html

This patent from Hon Hai Precision includes some basic claims to carbon nanotube arrays in field emitters having a flatness of less than 1 micron for improved uniformity of emission.

1. A carbon nanotube-based field emission device comprising: a cathode electrode; and a carbon nanotube array of nanotube members, the carbon nanotube array of the nanotube members extending from a root end to a growth end, the carbon nanotube array being aligned perpendicular to the cathode electrode with each given growth, end embedded in the cathode electrode and the corresponding root end being outwardly directed and exposed; wherein the growth end of die carbon nanotube array is in electrical contact with the cathode electrode, and the root end thereof defines a planar surface with a flatness of less than one micron across the carbon nanotube array.

However, the patent examiner may have neglected some pertinent prior art such as US Patent 6,283,812 (http://www.freepatentsonline.com/6283812.pdf) which specifically teaches truncating the endcaps of a nanotube array to achieve a flat profile or
http://cnnc.skku.ac.kr/paper/JSSuh1(APL).pdf which anticipates this patents priority by about a year (see specifically Fig. 1 and note the scale bar).