Patent ID: 7247981
Filing Date: 2007-07-24
Classification: H01J

Abstract:
1. An image forming apparatus comprising: a cathode substrate having plural electron emitting devices and a cathode electrode; an anode substrate positioned in an opposed relationship to said cathode substrate and having a light emitting member capable of emitting light by an irradiation with electrons emitting from said electron emitting devices, an anode electrode and a guard electrode; a plate-shaped spacer positioned between the cathode electrode and the anode electrode and between the cathode electrode and the guard electrode in contact with the cathode electrode and the anode electrode; and a frame member provided between a peripheral portion of the cathode electrode and the anode electrode and adapted to constitute a vacuum container together with the cathode substrate and the anode substrate: wherein the guard electrode is positioned between the anode electrode and the frame member, and a distance x [m] between the anode electrode and the guard electrode, a height hs [m] of the spacer, a potential Va [V] of the anode and a gap Lg [m] between the guard electrode and the spacer satisfy a following condition: