Patent ID: 8519627

Claim:
A field emission device, comprising: a cathode substrate; an anode substrate, the anode and cathode substrates being spaced apart to face each other; a plurality of cathode electrode blocks electrically separated from each other on the cathode substrate, wherein the cathode electrode blocks include a first cathode electrode block, a second cathode electrode block and a third cathode electrode block, the second cathode electrode block is disposed in a first direction from the first cathode electrode block, the third cathode electrode block is disposed in a second direction from the first cathode electrode block, and the first direction is different from the second direction; a plurality of field emitters spaced apart from each other on the cathode electrode blocks, each of the cathode electrode blocks having a group of the field emitters disposed thereupon; an anode electrode formed on the anode substrate; a fluorescent layer formed on the anode electrode; a gate electrode interposed between the cathode substrate and the anode substrate, the gate electrode having a constant gate voltage applied thereto and being disposed for inducing electron emission from all of the field emitters, wherein the gate electrode is the only gate electrode included in the field emission device and is continuously disposed over all of the cathode electrode blocks; a gate insulating layer interposed between the cathode electrode blocks and the gate electrode to insulate the gate electrode from the cathode electrode blocks; and a cathode current controller electrically connected to the cathode electrode blocks to control current flowing in the cathode electrode blocks so as to control an amount of electron emission from one or more of the field emitters as the gate voltage is kept constant.