Image forming apparatus
AssigneeCanon Kabushiki Kaisha
InventorsTetsuya Ohta, Yutaka Kakehi, Toshiyuki Yamada
Life of this patent
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Abstract
An image forming apparatus includes an image bearing member, a transfer member, a voltage source, a current detecting portion, a controller, and a receiving portion. During the recording material being passing through the transfer portion, the controller controls a voltage applied to a transfer member on the basis of a detection result of the current detecting portion so that a current flowing through the transfer member falls within a predetermined range. The controller sets at least one of an upper limit and a lower limit of the predetermined range on the basis of a predetermined voltage changing instruction received by the receiving portion.
Claims28
An image forming apparatus comprising:
- an image bearing member configured to bear a toner image;
- a transfer member provided in contact with said image bearing member and configured to transfer the toner image from said image bearing member onto a recording material at a transfer portion under application of a voltage thereto;
- a voltage source configured to apply the voltage to said transfer member;
- a current detecting portion configured to detect current information on a current flowing through said transfer member;
- a controller configured to carry out constant-voltage control so that the voltage applied to said transfer member is a predetermined voltage during the recording material being passing through the transfer portion,
- wherein during the recording material being passing through the transfer portion, said controller controls the voltage applied to said transfer member on the basis of a detection result of said current detecting portion so that the current flowing through said transfer member falls within a predetermined range;
- and
- a receiving portion configured to receive an instruction to change the predetermined voltage from an operator,
- wherein said controller sets at least one of an upper limit and a lower limit of the predetermined range on the basis of the instruction received by said receiving portion.
An image forming apparatus comprising:
- an image bearing member configured to bear a toner image;
- a transfer member provided in contact with said image bearing member and configured to transfer the toner image from said image bearing member onto a recording material at a transfer portion under application of a voltage thereto;
- a voltage source configured to apply the voltage to said transfer member;
- a current detecting portion configured to detect information on a current flowing through said transfer member;
- and
- a controller configured to carry out constant-voltage control so that the voltage applied to said transfer member is a predetermined voltage during the recording material being passing through the transfer portion, wherein during the recording material being passing through the transfer portion, said controller controls the voltage applied to said transfer member on the basis of a detection result of said current detecting portion so that the current flowing through said transfer member falls within a predetermined range;
- and
- wherein when the current flowing through said transfer member is out of the predetermined range during a first recording material being passing through the transfer portion in continuous image formation for continuously forming images on a plurality of recording materials, said controller changes, during the first recording material being passing through the transfer portion, the predetermined voltage applied to said transfer member, and said controller determines an initial value of the predetermined voltage for a second recording material to be passed after the first recording material, on the basis of the predetermined voltage changed during the first recording material being passing through the transfer portion.
Dependencies are inferred from the claim text.