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AssigneeCanon Kabushiki Kaisha
InventorsIchiro Nomura, Masato Yamanobe, Hidetoshi Suzuki, Toshihiko Takeda, Tatsuya Iwasaki
Estimating the term…
In an electron beam apparatus comprising an enclosure in which an electron-emitting device having an electron-emitting region between opposite electrodes is disposed, the electron-emitting device exhibits such a characteristic as that an emission current is uniquely determined with respect to a device voltage. The interior of the enclosure is maintained under an atmosphere effective to prevent structural changes of the electron-emitting device. An image-forming apparatus comprises an enclosure in which an electron source and an image-forming member are disposed, the electron source comprising the above electron-emitting device. An emission current is stable with a very small change in the amount of electrons emitted, a sharp image is produced with high contrast, and gradation control is easily carried out.
An image forming apparatus, comprising an electron beam apparatus that comprises an enclosure in which an electron-emitting device having an electron-emitting region between opposite electrodes is disposed, wherein a material containing carbon as a main ingredient is present at the electron emitting region and its vicinity, and wherein an interior of said enclosure is maintained under an atmosphere in which a partial pressure of residual carbon compounds is less than 1×10−10 Torr, so as to prevent materials containing carbon as a main ingredient from further depositing on said electron emitting device.
An image forming apparatus for forming an image responsive to an input signal, comprising an enclosure in which an electron-emitting device having an electron-emitting region between opposite electrodes and an image forming member are disposed, wherein a material containing carbon as a main ingredient is present at the electron emitting region and its vicinity, and wherein an interior of said enclosure is maintained under an atmosphere in which a partial pressure of residual carbon compounds is less than 1×10−10 Torr, so as to prevent materials containing carbon as a main ingredient from further depositing on said electron emitting device.
An image forming apparatus comprising at least one electron beam apparatus that comprises an enclosure in which an electron-emitting device is disposed, wherein said electron-emitting device has an electron-emitting region in which material containing carbon exists, and wherein an interior of said enclosure is maintained under an atmosphere in which a partial pressure of residual carbon compounds is less than 1×10−10 Torr.
An image forming apparatus comprising at least one electron beam apparatus that comprises an enclosure in which an electron-emitting device is disposed, wherein said electron-emitting device has an electron-emitting region in which a material containing carbon exists, and wherein an interior of said enclosure is maintained under an atmosphere in which a partial pressure of residual carbon compounds is less than 1×10−8 Torr.
Dependencies are inferred from the claim text.