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US 7,116,922 B2Granted
Charging apparatus
AssigneeCanon Kabushiki Kaisha
InventorsNorio Takahashi, Harumi Ishiyama, Jun Hirabayashi
Life of this patent
Estimating the term…
Abstract
A charging apparatus includes a charging section supplied with an AC voltage and for electrically charging a member to be charged; a current measuring section for measuring a current flowing between the charging section and the member to be charged when the AC voltage is supplied to the charging section; and a particular current extraction section for extracting from the current a particular current having a particular frequency.
Claims54
A charging apparatus comprising:
- charging means for being supplied with an AC voltage and for electrically charging a member to be charged;
- current measuring means for measuring a current flowing between said charging means and the member to be charged when the AC voltage is supplied to said charging means;
- and
- particular current extraction means for extracting from the current a particular current having a particular frequency,
- wherein the particular frequency is high as compared to the frequency of the AC voltage.
2 more elements
A charging apparatus comprising:
- charging means for being supplied with an AC voltage and for electrically charging a member to be charged;
- current measuring means for measuring a current flowing between said charging means and the member to be charged when the AC voltage is supplied to said charging means;
- and
- control means for controlling a voltage applied to said charging means on the basis of a particular current having a particular frequency of the current when said charging means charges an image forming region of the member to be charged,
- wherein the particular frequency is high as compared to the frequency of the AC voltage.
2 more elements
A charging apparatus comprising:
- charging means for being supplied with an AC voltage and for electrically charging a member to be charged;
- current measuring means for measuring a current flowing between said charging means and the member to be charged when the AC voltage is supplied to said charging means;
- and
- control means for applying to said charging means a plurality of AC voltages having different peak-to-peak voltages to obtain a plurality of AC voltages of which maximum values of particular currents provided by differences between the currents and currents averaged in unit periods are not more than a predetermined value, and for controlling, when said charging apparatus charges an image forming region of the member to be charged, the AC voltage applied to said charging means on the basis of an AC voltage having a minimum peak-to-peak voltage of such a plurality of AC voltages.
1 more element
Dependencies are inferred from the claim text.