Investigation of the focus characteristics of a triode structure in FED

In a field emission display panel, the triode structure [1] has been used to decrease the driving voltage. Because a very strong electric field has been applied in front of the field emitters, the electron beam usually divergences seriously in a normal triode structure [2][3]. In this paper, a new triode structure with an additional focus electrode has been proposed [4]. A numerical program has been used to calculate the focus characteristic of this triode structure. This paper also analyzes the variation of the current density distribution on the screen with different focus voltages.