Canon Kabushiki Kaisha

Mikihiko Hamada

Shuichi Tetsuno

Toshihiko Takayama

Shinsuke Kobayashi

Jun Hara

Kazuhiro Funatani

Shuhei Tokiwa

Shunsuke Matsushita

Shimpei Ishikawa

Hiroko Katagiri

An image forming apparatus includes a photosensitive member, a charging member, an exposing device, a developing device, a transfer member, a brush, a voltage applying portion, and a control portion controlling a surface potential of the photosensitive member at the brush contacting position. When a value of subtracting a value of the surface potential of the photosensitive member in the brush contacting position from a value of the brush voltage is defined as a contacting position potential difference, the control portion controls the surface potential of the photosensitive member in the brush contacting position so that the contacting position potential difference is changed from a first potential difference to a second potential difference in a predetermined direction which is either one of an increasing direction or a decreasing direction, and then the contacting position potential difference is changed from the second potential difference to a third potential difference in the predetermined direction.

Image forming apparatus

An image forming apparatus includes a photosensitive drum, a charging member, a developing member, a transfer member, first and second gears, a drive source, and a control unit. The charging member contacts the photosensitive drum and forms a charging portion to charge a surface of the photosensitive drum. The control unit performs control in such a manner that an image forming operation of performing image formation by rotating the photosensitive drum at a first rotational speed is executable. Where the control unit executes the image forming operation, the control unit performs a switch operation of stopping the photosensitive drum in a state in which the photosensitive drum is driven, while a non-image forming operation to be executed after the image forming operation is executed, and rotationally driving the photosensitive drum again at a second rotational speed faster than the first rotational speed, a plurality of times.

An image forming apparatus includes an image bearing member, a brush, and a controller. The controller controls so that, in a case where, in a state where a recording material trailing edge in a conveyance direction is sandwiched at a transfer portion, an area of the image bearing member in the conveyance direction where the recording material is sandwiched in a direction perpendicular to the conveyance direction is a first area, and an area of the image bearing member in the conveyance direction where the recording material is not sandwiched is a second area, a first potential difference formed between a surface potential formed on the second area and a brush voltage, which is based on first information, when the second area reaches the brush and a second potential difference formed between the second area surface potential and the brush voltage, which is based on second information, are different.

Controlling voltage in an image forming apparatus including a brush that comes into contact with an image bearing member

An image-forming apparatus to execute an image-forming operation includes an image bearing member, a charging member to charge at a charging portion a surface of, and a developing member to supply at a developing portion toner to, the image bearing member. When a rotating image bearing member stops rotating, a surface potential of the image bearing member formed on the developing portion is defined as V, a developing voltage applied to the developing member is defined as V, a charging voltage applied to the charging member is defined as V, and a surface potential of the image bearing member formed on the charging portion is defined as V. A first potential difference, which is a potential difference between Vand V, and a second potential difference, which is a potential difference between Vand V, are controlled based on information about a number of execution times of the image-forming operation.

Image-forming apparatus to control potential difference based on image-forming operation

An image forming apparatus including an image bearing member, a charging member, a developing roller, a transfer roller, and a brush configured to be brought into contact with a surface of the image bearing member on a side downstream of a transfer portion and upstream of a charging portion in a rotation direction of the image bearing member and in which, wherein, after the transfer of a developer image onto a transferred member, a developer remaining on the surface of the image bearing member is collected by the developing roller, the brush is disposed such that, in a cross section perpendicular to a rotation axis of the image bearing member, a contact region of the surface of the image bearing member in contact with the brush overlaps a virtual line containing the rotation axis of the image bearing member and extending upward from the rotation axis in a vertical direction.

Growing community of inventors

Kanagawa, Japan

Mikihiko Hamada