Normally-on driving under-gate CNT FED with focus electrode

A new structure of under-gate carbon nanotube (CNT) field emission display (FED)panel is proposed in this paper with normally-on driving scheme. In this structure, the gate electrode is still located beneath the cathode with the cathode and focus electrode arranged alternately. The effect of the under-gate is to prevent the field emission when the negative voltage is applied on the gate electrode. By applying negative voltage on the focus electrode, the electron trajectories are focused. The electric field inside the emission region is calculated by finite element method. The emission property of the CNT film and spot on the anode are also studied by numerically. The results verify the disadvantages of the conventional under-gate structure. Comparing the working property of these two different under-gate FED, the new driving scheme and focus electrode benefit to achieving large emission area, notable emission uniformity, high luminance efficacy and high anode voltage.