Patent ID: 8080928

Claim:
An electron-emitting device comprising: a substantially linear convex portion forming a projection on a substrate; a first electrode and a second electrode formed on the substrate across the convex portion; a conductive film that connects the first electrode and the second electrode; and an electron-emitting portion that is composed of a gap formed on the conductive film and is present on the convex portion, wherein, supposing that a direction in which the convex portion extends is defined as a Y direction, a direction orthogonal to the Y direction on the substrate is defined as an X direction, and a normal direction of the substrate is defined as a Z direction, a top portion of the convex portion in X-Z section has a curved portion having a convex shape toward the projecting direction of the convex portion, and supposing that a voltage applied between the first electrode and the second electrode upon a electron emission is defined as Vf, a distance between an anode electrode, which is opposite to the substrate, and the substrate is defined as L, a voltage applied between the substrate and the anode electrode is defined as Va, a height from a surface of the substrate to the top of the convex portion is defined as H, a width of the convex portion at a bottom surface in the X direction is defined as W, and a distance between a center of the gap in the X direction and the top of the convex portion is defined as Xg, H ≧( Vf×L )/(π× Va ) | Xg|≦ 0.35 W are established, wherein a shape of the convex portion in the X-Z section changes along the Y direction.