Patent ID: 7135823

Claim:
An image forming apparatus comprising: a cathode; a gate; an anode; an electron emitting element arranged on the cathode; an image forming member that is arranged opposite to the electron emitting element and is made to emit light by a collision of an electron, emitted from the electron emitting element by applying an electric field to the electron emitting element, to form an image; a deflection electrode that deflects an orbit of the electron emitted from the electron emitting element and headed toward the anode; and a driver, wherein assuming that an electric field required to start electron emission from the electron emitting element is Ee, that an electric field applied to the electron emitting element by applying voltage to the anode is Ea and that an electric field applied to the electron emitting element by applying voltage to the gate is Eg, the driver applies voltages to the cathode, the gate, and the anode in such a way that Ea>Ee (i) or Ea+Eg>Ee and Ea>Eg (ii) is satisfied.