Image forming apparatus and charging device therefor
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Abstract
A charging device of the present invention includes a charge roller adjoining or contacting the surface of a photoconductive element. A DC and an AC voltage source output a DC and an AC voltage, respectively. A voltage applying device superposes the DC and AC voltage and applies the resulting superposed voltage to the charge roller. A waveform controller causes the AC voltage source to generate an AC voltage having the waveform pattern of particular noise and frequency lying in a preselected range.
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Citations
31 Claims
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1-21. -21. (canceled)
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22. A charging device comprising:
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a charge roller adjoining or contacting a surface of a photoconductive element;
a DC voltage source configured to output a DC voltage; and
an AC voltage source configured to output an AC voltage, the DC voltage and the AC voltage being applied to said charge roller, the AC voltage having a waveform pattern of at least one of white noise and pink noise. - View Dependent Claims (23, 24, 25, 26)
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27. A process cartridge comprising:
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a photoconductive element;
a cartridge case by which said photoconductive element is rotatably supported;
a charging device disposed in said cartridge case and configured to establish a potential difference between said charging device and said photoconductive element to thereby uniformly charge a surface of said photoconductive element; and
a developing device disposed in said cartridge case and configured to feed toner to the surface of said photoconductive element;
said charging device comprising;
a charge roller adjoining or contacting a surface of said photoconductive element;
a DC voltage source configured to output a DC voltage; and
an AC voltage source configured to output an AC voltage, the DC voltage and the AC voltage being applied to said charge roller, the AC voltage having a waveform pattern of at least one of white noise and pink noise.
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28. An image forming apparatus comprising:
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a process cartridge comprising a photoconductive element, a cartridge case by which said photoconductive element is rotatably supported, a charging device disposed in said cartridge case and configured to establish a potential difference between said charging device and said photoconductive element to thereby uniformly charge a surface of said photoconductive element, and a developing device disposed in said cartridge case and configured to feed toner to said surface of said photoconductive element;
an optical scanning unit configured to optically scan the surface of said photoconductive element charged by said charging device; and
an image transferring device configured to transfer the toner from the surface of said photoconductive element to a recording medium;
said charging device comprising;
a charge roller adjoining or contacting a surface of said photoconductive element;
a DC voltage source configured to output a DC voltage; and
an AC voltage source configured to output an AC voltage, the DC voltage and the AC voltage being applied to said charge roller, the AC voltage having a waveform pattern of at least one of white noise and pink noise.
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29. An image forming apparatus comprising:
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a photoconductive element;
a charging device configured to establish a potential difference between said charging device and said photoconductive element to thereby uniformly charge a surface of said photoconductive element, said charging device comprising a charge roller adjoining or contacting a surface of said photoconductive element, a DC voltage source configured to output a DC voltage, an AC voltage source configured to output an AC voltage, the DC voltage and the AC voltage being applied to said charge roller, the AC voltage having a waveform pattern of at least one of white noise and pink noise;
an optical scanning device configured to optically scan the surface of said photoconductive element charged by said charging device;
a developing device configured to transfer toner to the surface of said photoconductive element scanned by said optical scanning device; and
an image transferring device configured to transfer the toner from the surface of said photoconductive element to a recording medium.
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30. A copier comprising:
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an image reading device configures to read a document image; and
an image forming apparatus configured to form an image on a recording medium in accordance with image data output from said image reading device;
said image forming apparatus comprising;
a process cartridge comprising a photoconductive element, a cartridge case by which said photoconductive element is rotatably supported, a charging device disposed in said cartridge case and configured to establish a potential difference between said charging device and said photoconductive element to thereby uniformly charge a surface of said photoconductive element, and a developing device disposed in said cartridge case and configured to feed toner to said surface of said photoconductive element;
an optical scanning unit configured to optically scan the surface of said photoconductive element charged by said charging device; and
an image transferring device configured to transfer the toner from the surface of said photoconductive element to a recording medium;
said charging device comprising;
a charge roller adjoining or contacting a surface of the photoconductive element;
a DC voltage source configured to output a DC voltage; and
an AC voltage source configured to output an AC voltage, the DC voltage and the AC voltage being applied to said charge roller, the AC voltage having a waveform pattern of at least one of white noise and pink noise.
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31. A copier comprising:
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an image reading device configured to read a document image;
an image forming apparatus configured to form an image on a recording medium in accordance with image data output from said image reading device;
a photoconductive element;
a charging device configured to establish a potential difference between said charging device and said photoconductive element to thereby uniformly charge a surface of said photoconductive element, said charging device comprising a charge roller adjoining or contacting a surface of a photoconductive element, a DC voltage source configured to output a DC voltage and an AC voltage source configured to output an AC voltage, the DC voltage and the AC voltage being applied to said charge roller, the AC voltage having a waveform pattern of at least one of white noise and pink noise;
an optical scanning device configured to optically scan the surface of said photoconductive element charged by said charging device;
a developing device configured to transfer toner to the surface of said photoconductive element scanned by said optical scanning device; and
an image transferring device configured to transfer the toner from the surface of said photoconductive element to a recording medium.
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Specification