The nonuniformity in field emission is still a critical problem hampering the commercial application of field-emission displays. In the present study, a microprocessor-based technique is developed to overcome this difficulty in order to finally improve the display uniformity. The principle of the technique and the experimental details are given. One of the key functions of this method, i.e., control of emission-current level, was investigated. This capability was then demonstrated by using it to control the performance of a single lighting element, i.e., a pixel of an ultralarge display screen. (C) 2003 American Vacuum Society.