METHODS AND SYSTEMS FOR COMPENSATING ROW-TO-ROW BRIGHTNESS VARIATIONS OF A FIELD EMISSION DISPLAY

摘要

METHODS FOR COMPENSATING FOR BRIGHTNESS VARIATIONS IN A FIELD EMISSION DEVICE.IN ONE EMBODIMENT, A METHOD AND SYSTEM ARE DESCRIBED FOR MEASURING THE RELATIVE BRIGHTNESS OF ROWS OF A FIELD EMISSION DISPLAY (FED) DEVICE, STORING INFORMATION REPRESENTING THE MEASURED BRIGHTNESS INTO A CORRECTION TABLE (60) AND USING THE CORRECTION TABLE TO PROVIDE UNIFORM ROW BRIGHTNESS IN THE DISPLAY BY ADJUSTING ROW VOLTAGES AND/OR ROW ON-TIME PERIODS.A SPECIAL MEASUREMENT PROCESS IS DESCRIBED FOR PROVIDING ACCURATE CURRENT MEASUREMENTS ON THE ROWS. THIS EMBODIMENT COMPENSATES FOR BRIGHTNESS VARIATIONS OF THE ROWS, E.G., FOR ROWS NEAR THE SPACER WALLS (30). IN ANOTHER EMBODIMENT, A PERIODIC SIGNAL, E.G., A HIGH FREQUENCY NOISE SIGNAL (340), IS ADDED TO THE ROW ON-TIME PULSE (410) IN ORDER TO CAMOUFLAGE BRIGHTNESS VARIATIONS IN THE ROWS NEAR THE SPACER WALLS. IN ANOTHER EMBODIMENT, THE AREA UNDER THE ROW ON-TIME PULSE IS ADJUSTED TO PROVIDE ROW-BY-ROW BRIGHTNESS COMPENSATION BASED ON CORRECTION VALUES STORED IN A MEMORY RESIDENT CORRECTION TABLE. IN ANOTHER EMBODIMENT, THE BRIGHTNESS OF EACH ROW IS MEASURED AND COMPILED INTO A DATA PROFILE FOR THE FED. THE DATA PROFILE IS USED TO CONTROL CATHODE BURN-IN PROCESSES SO THAT BRIGHTNESS VARIATIONS ARE CORRECTED BY PHYSICALLY ALTERING THE CHARACTERISTICS OF THE EMITTERS (40) OF THE ROWS.(FIG 6)