Canon Kabushiki Kaisha

Hiroko Katagiri

Shinji Katagiri

Shuichi Tetsuno

Toshihiko Takayama

Koji An

Shingo Ito

Shinsuke Kobayashi

Takashi Mukai

Mikihiko Hamada

In an image forming apparatus including a transfer member that primarily transfers a developer image from an image bearing member onto an intermediate transfer belt by applying an electric current to an intermediate transfer belt in a circumferential direction, a control unit which executes a first mode in which to rotate the intermediate transfer belt and a second mode in which to rotate the intermediate transfer belt at a rotation speed higher than that in the first mode. The control unit performs control such that an absolute value of a second voltage to be applied to the transfer member in a case of performing primary transfer in the second mode is less than an absolute value of a first voltage to be applied to the transfer member in a case of performing the primary transfer in the first mode.

Image forming apparatus to suppress scattering of toner

An image forming apparatus includes a rotatable image bearing member, a developing member to develop an electrostatic latent image at a developing portion, a transfer member to transfer a developer image to a recording member at a transfer portion; and a brush provided with a plurality of base materials contacting the image bearing member at downstream of the transfer portion and upstream of the developing portion in a rotational direction of the image bearing member. The developer remaining on the surface of the image bearing member is collected in the developing portion. An average distance between base materials of the brush with respect to a rotational axis direction of the image bearing member is larger than an average particle diameter of the developer, and is equal to or less than a length corresponding to a special frequency visually recognizable by a user when the image formed by the image forming apparatus is observed by the user.

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 a rotatable image bearing member, a developing member to develop an electrostatic latent image at a developing portion, a transfer member to transfer a developer image to a recording member at a transfer portion; and a brush provided with a plurality of base materials contacting the image bearing member at downstream of the transfer portion and upstream of the developing portion in a rotational direction of the image bearing member. The developer remaining on the surface of the image bearing member is collected in the developing portion. An average distance between base materials of the brush with respect to a rotational axis direction of the image bearing member is larger than an average particle diameter of the developer, and is equal to or less than a length corresponding to a spatial frequency visually recognizable by a user when the image formed by the image forming apparatus is observed by the user.

An image forming operation forms an image on a transfer target in a state in which a developing member is located at a first position where a developer is supplied to an image bearing member and a first charging voltage is applied to a charging unit. The image forming operation is followed by: a first rotating operation of rotating the image bearing member in a state in which the developing member is located at the first position and a second charging voltage smaller in absolute value than the first charging voltage is applied; and a second rotating operation of rotating the image bearing member in a state in which the developing member is located at a second position where the developer is not supplied to the image bearing member and a third charging voltage smaller in absolute value than the second charging voltage is applied.

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Tokyo, Japan

Hiroko Katagiri