Patent ID: 8154184

Claim:
An electron emitting device comprising: an insulating member disposed on a substrate, the insulating member having a recess portion on a surface of the insulating member and the surface of the insulating member having a side face and an upper face, the side face continuing to the recess portion and extending toward the substrate, the upper face more distantly extending from the substrate than the side face and continuing to the recess portion; a gate disposed on the upper face; and a cathode disposed on the side face, the cathode having a protruding portion protruding from a side-face-sided edge of the recess portion, at which the side face continues to the recess portion, toward a direction away from the substrate, the protruding portion being in opposition to the gate, wherein a length of the protruding portion in a direction along the side-face-sided edge of the recess portion is shorter than a length of the gate in the direction along the side-face-sided edge of the recess portion.