Electron source, image-forming apparatus comprising the same and method of driving such an image-forming apparatus

An electron source comprising a plurality of electron-emitting devices having a pair of electrodes and an electroconductive thin film disposed between the electrodes and containing an electron emitting region and a drive means for driving said plurality of electron-emitting devices, wherein said drive means applies a voltage above a threshold level to the electrode of selected ones of said plurality of electron-emitting devices according to an image signal to cause the selected electron-emitting devices to emit electrons and also a voltage pulse for bringing said plurality of electron-emitting devices into a high resistance state, said voltage pulse having a polarity reverse to that of the voltage for causing electron emission and a voltage rising rate of greater than 10V/sec, said voltage pulse being applied in a period when said voltage above the threshold level is not applied, and wherein the voltage pulse for bringing the electron-emitting devices into a high resistance state has a wave height greater than the voltage where the device current becomes a local maximum.

An electron source comprising a plurality of electron-emitting devices having a pair of electrodes and an electroconductive thin film disposed between the electrodes and containing an electron emitting region and a drive means for driving said plurality of electron-emitting devices, wherein said drive means applies a voltage above a threshold level to the electrodes of selected ones of said plurality of electron-emitting devices according to an image signal to cause the selected electron-emitting devices to emit electrons and also a voltage pulse for bringing said plurality of electron-emitting devices into a high resistance state, said voltage pulse having a polarity reverse to that of the voltage for causing electron emission and a voltage rising rate of greater than 10V/sec, said voltage pulse being applied in a period when said voltage above the threshold level is not applied, wherein the voltage pulse for bringing the electron-emitting devices into a high resistance state has a wave height greater than the voltage applied to the unselected electron-emitting devices, and wherein the electron-emitting devices are selectively driven by X-direction wirings and Y-direction wirings arranged in a matrix.

An image forming apparatus comprising a plurality of electron-emitting devices having a pair of electrodes and an electroconductive thin film disposed between the electrodes and containing an electron emitting region, an image-forming member and a drive means for driving said plurality of electron-emitting devices to form an image on the image-forming member through electrons emitted from the electron-emitting devices, wherein said drive means applies a voltage above a threshold level to the electrodes of selected ones of said plurality of electron-emitting devices according to an image signal to cause the selected electron-emitting devices to emit electrons and also a voltage pulse for bringing said plurality of electron-emitting devices into a temporary high resistance state, said voltage pulse having a polarity reverse to that of the voltage for causing electron emission and a voltage rising or falling rate to zero volt of greater than 10V/sec, said voltage pulse being applied in a period when said voltage above the threshold level is not applied.

An image-forming apparatus comprising a plurality of electron-emitting devices having a pair of electrodes and an electroconductive thin film disposed between the electrodes and containing an electron emitting region, a drive means for driving said plurality of electron-emitting devices and an image-forming member, wherein:

• said drive means applies a voltage above a threshold level to the electrodes of selected ones of said plurality of electron-emitting devices according to an image signal to cause the selected electron-emitting devices to emit electrons and also a voltage pulse for bringing said plurality of electron-emitting devices into a high resistance state, said voltage pulse having a polarity reverse to that of the voltage for causing electron emission and a voltage rising rate of greater than 10V/sec., said voltage pulse being applied in a period when said voltage above the threshold level is not applied, and
• wherein the image-forming member is arranged out of the areas irradiated by electron beams emitted when the voltage pulse for bringing into a high resistance state is applied.

An image-forming apparatus comprising a plurality of electron-emitting devices having a pair of electrodes and an electroconductive thin film disposed between the electrodes and containing an electron emitting region, a drive means for driving said plurality of electron-emitting devices and an image-forming member, wherein:

• said drive means applies a voltage above a threshold level to the electrodes of selected ones of said plurality of electron-emitting devices according to an image signal to cause the selected electron-emitting devices to emit electrons and also a voltage pulse for bringing said plurality of electron-emitting devices into a high resistance state, said voltage pulse having a polarity reverse to that of the voltage for causing electron emission and a voltage rising rate of greater than 10V/sec., and
• wherein the voltage pulse for bringing the electron-emitting devices into a high resistance state has a wave height greater than the voltage where the device current becomes a local maximum.

An image-forming apparatus comprising a plurality of electron-emitting devices having a pair of electrodes and an electroconductive thin film disposed between the electrodes and containing an electron emitting region, a drive means for driving said plurality of electron-emitting devices and an image-forming member, wherein:

• said drive means applies a voltage above a threshold level to the electrodes of selected ones of said plurality of electron-emitting devices according to an image signal to cause the selected electron-emitting devices to emit electrons and also a voltage pulse for bringing said plurality of electron-emitting devices into a high resistance state, said voltage pulse having a polarity reverse to that of the voltage for causing electron emission and a voltage rising rate of greater than 10V/sec., said voltage pulse being applied in a period when said voltage above the threshold level is not applied, and
• wherein the voltage pulse for bringing the electron-emitting devices into a high resistance state has a wave height greater than the voltage applied to the unselected electron-emitting devices, and
• wherein the electron-emitting devices are selectively driven by X-direction wirings and Y-direction wirings arranged in a matrix.

An image forming apparatus comprising a plurality of electron-emitting devices having a pair of electrodes and an electroconductive thin film disposed between the electrodes and containing an electron emitting region, a drive means for driving said plurality of electron-emitting devices and an image-forming member, wherein:

• said drive means applies a voltage above a threshold level to the electrodes of selected ones of said plurality of electron-emitting devices according to an image signal to cause the selected electron-emitting devices to emit electrons and also a voltage pulse for bringing said plurality of electron-emitting devices into a high resistance state, said voltage pulse having a polarity reverse to that of the voltage for causing electron emission and a voltage rising rate of greater than 10V/sec., said voltage pulse being applied in a period when said voltage above the threshold level is not applied,
• wherein the image-forming member is arranged out of the areas irradiated by electron beams emitted when the voltage pulse for bringing into a high resistance state is applied, and
• wherein the electron-emitting devices are surface conduction electron-emitting devices.