Analysis and performance of Candescent´s FED focusing structure

Candescent has developed a field emission flat panel display, the ThinCRT, based on high voltage phosphors to take advantage of their high efficiency, long life, commercial availability, and wide color gamut. For high voltage operation, a 1 mm or larger insulating vacuum gap is required between the cathode and anode. To avoid loss of efficiency and color purity, the naturally divergent beam of electrons produced by Spindt field emitters in each subpixel on the cathode is focused across this gap into the appropriate phosphor on the faceplate. This paper describes Candescent´s unique focusing structure, the numerical methods used to model it, and measurements of its performance in FEDs