The present disclosure provides for various advantageous methods and apparatus of controlling electron emission. One of the broader forms of the present disclosure involves an electron emission element, comprising an electron emitter including an electron emission region disposed between a gate electrode and a cathode electrode. An anode is disposed above the electron emission region, and a voltage set is disposed above the anode. A first voltage applied between the gate electrode and the cathode electrode controls a quantity of electrons generated from the electron emission region. A second voltage applied to the anode extracts generated electrons. A third voltage applied to the voltage set controls a direction of electrons extracted through the anode.