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US 2020/0004193 A1Published application
Image forming apparatus
AssigneeCanon Kabushiki Kaisha
InventorsTaisuke Minagawa, Ken Yokoyama, Yasuharu Hirado
Life of this patent
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Abstract
A controller controls a secondary transfer power source such that a current having a first value flows in a secondary transfer portion in a case where a transfer material with an image formed on a first surface thereof has been conveyed for less than a predetermined amount of time in a second conveyance path. Moreover, the controller controls the secondary transfer power source such that a current having a second value larger in absolute value than the first value flows in the secondary transfer portion in a case where the transfer material with an image formed on the first surface thereof is conveyed to the secondary transfer portion after waiting for the predetermined amount of time or more in the second conveyance path.
Claims28
An image forming apparatus comprising:
- a container unit configured to contain a transfer material;
- an image bearing member configured to bear a toner image;
- a transfer member configured to be in contact with the image bearing member to form a transfer portion to transfer a toner image from the image bearing member to a transfer material;
- a transfer power source configured to apply a voltage to the transfer member;
- a fixing unit located on a downstream side of the transfer portion in a transfer material conveyance direction and configured to fix a toner image to a transfer material by heating the transfer material;
- a first conveyance path configured to guide a transfer material being conveyed from the container unit toward the transfer portion;
- a second conveyance path configured to join the first conveyance path and to guide a transfer material on which an image has been formed on a first surface and which, after passing through the fixing unit, is re-conveyed to the transfer portion, wherein a toner image is transferred to a second surface of the transfer material opposite to the first surface at the transfer portion;
- and
- a control unit configured to control the transfer power source such that, in transferring a toner image, a current having a predetermined value flows from the transfer member toward the image bearing member,
- wherein the control unit controls the transfer power source such that a current having a first value flows from the transfer member toward the image bearing member in a case where the transfer material with an image formed on the first surface thereof has been conveyed for less than a predetermined time in the second conveyance path, and controls the transfer power source such that a current having a second value larger in absolute value than the first value flows from the transfer member toward the image bearing member in a case where the transfer material with an image formed on the first surface thereof is conveyed to the transfer portion after waiting for the predetermined amount of time or more in the second conveyance path.
7 more elements
An image forming apparatus comprising:
- a container unit configured to contain a transfer material;
- an image bearing member configured to bear a toner image;
- a transfer member configured to be in contact with the image bearing member to form a transfer portion to transfer a toner image from the image bearing member to a transfer material;
- a transfer power source configured to apply a voltage to the transfer member;
- a fixing unit located on a downstream side of the transfer portion in a transfer material conveyance direction and configured to fix a toner image to a transfer material by heating the transfer material;
- a first conveyance path configured to guide a transfer material being conveyed from the container unit toward the transfer portion;
- a second conveyance path configured to join the first conveyance path and to guide a transfer material on which an image has been formed on a first surface and which, after passing through the fixing unit, is re-conveyed to the transfer portion, wherein a toner image is transferred to a second surface of the transfer material opposite to the first surface at the transfer portion;
- and
- a control unit configured to control the transfer power source such that, in transferring a toner image to the first surface, a current having a first value flows from the transfer member toward the image bearing member,
- wherein the control unit controls the transfer power source such that a current having a second value larger in absolute value than the first value flows from the transfer member toward the image bearing member in a case where the transfer material with an image formed on the first surface thereof is conveyed to the transfer portion after waiting for a predetermined amount of time or more in the second conveyance path.
7 more elements
Dependencies are inferred from the claim text.