CONSTANT CURRENT DRIVING CIRCUIT FOR FIELD EMISSION DEVICE

摘要

The present invention relates to a constant current driving circuit for a field emission device, and more particularly, to a constant current driving circuit for a field emission device, wherein a ground current of an anode electrode is measured in real time and the measured ground current is fedback to vary the frequency and duty ratio of a voltage applied to gate and cathode electrodes of a field emission device, thereby causing the ground current of the anode electrode to be constantly maintained. To this end, the present invention provides a constant current driving circuit for a field emission device having an anode electrode formed on a front substrate, gate and cathode electrodes formed on a rear substrate disposed opposite to the front substrate to be spaced apart from the front substrate by a predetermined distance, and an emitter formed on a top surface of the cathode electrode. The constant current driving circuit comprises a current detection circuit for detecting a ground current of the anode electrode; an input power unit for applying a driving AC voltage for emitting electrons from the emitter to the gate and cathode electrodes; and a feedback circuit unit for comparing the ground current of the anode electrode detected by the current detection circuit with a predetermined reference voltage to obtain a current variation and providing the input power unit with a frequency signal for varying a frequency of the driving AC voltage or a duty ratio signal for varying a duty ratio of the driving AC voltage in accordance with the current variation.