| US 7,348,722 B2 | ||
| Field emission device with focusing control electrode and field emission display | ||
| Pil-soo Ahn, Suwon-si (Korea, Republic of); and Hang-woo Lee, Suwon-si (Korea, Republic of) | ||
| Assigned to Samsung Electronics Co., Ltd., Suwon-si (Korea, Republic of) | ||
| Filed on Feb. 17, 2005, as Appl. No. 11/59,393. | ||
| Claims priority of application No. 10-2004-0011483 (KR), filed on Feb. 20, 2004. | ||
| Prior Publication US 2005/0189868 A1, Sep. 01, 2005 | ||
| Int. Cl. H01J 1/62 (2006.01) | ||
| U.S. Cl. 313—497 [313/310; 313/309] | 8 Claims |
| 1. A field emission device comprising:
a substrate;
a cathode electrode formed on the substrate;
a focusing control insulating layer formed on the cathode electrode, and having a first cavity that exposes a portion of the
cathode electrode;
an electron emission source disposed on the cathode electrode, said electron emission source being exposed by the first cavity;
a focusing control electrode formed on the focusing control insulating layer and including a focusing control hole aligned
with the first cavity; and
means for applying to the focusing control electrode a voltage that is lower than the potential of the cathode electrode so
as to control the focus of an electron beam emitted from the electron emission source;
a gate insulating layer formed on the focusing control electrode, and having a second cavity aligned with the first cavity;
and
a gate electrode formed on the gate insulating layer, and having a gate hole aligned with the second cavity,
wherein an edge of the focusing control electrode facing the electron emission source is formed at a relative position, (x,
y) calculated by the following equations, with respect to an upper edge of the electron emission source:
C/2<x<2C
−E/2<y<2F/3,
wherein C denotes a radius of the electron emission source, E denotes a height of the electron emission source, and F denotes
a height from the upper portion of the electron emission source to the gate electrode.
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