Patent ID: 7471039

Claim:
A quadrode field emission display, comprising: an insulation substrate; a cathode and sub-gate layer comprising a cathode plate and a sub-gate electrode, the cathode plate and the sub-gate electrode disposed on a surface of the insulation substrate, the cathode plate being apart from the sub-gate electrode at a distance, the sub-gate electrode having a voltage level higher than a voltage level of the cathode plate normally, thereby attracting and leading electrons released from the cathode plate into the sub-gate electrode; a gate layer disposed above the cathode and the sub-gate layer, the gate layer having an opening corresponding to an edge of the cathode plate, the opening pierced through the gate layer to expose the edge of the cathode plate, so as to induce the cathode plate to excite a plurality of electrons; a dielectric layer, one portion of the dielectric layer disposed between the cathode plate and the gate layer, the other portion of the dielectric layer disposed between the sub-gate electrode and the gate layer, so as to respectively separate the cathode plate and the sub-gate electrode from the gate layer; and an anode plate disposed above the gate layer, so that the excited electrons are emitted and collide with the anode plate.