Canon Kabushiki Kaisha

Shuichi Tetsuno

Shinji Katagiri

Toshihiko Takayama

Shinsuke Kobayashi

Takayuki Tanaka

Jun Hara

Tsuguhiro Yoshida

Takahiro Ikeda

Kazuhiro Funatani

Mikihiko Hamada

Masaru Ohno

Masaru Shimura

Keisuke Ishizumi

Takaaki Akamatsu

Shohei Ishio

Masashi Tanaka

Kenichi Ogawa

Koji An

Shogo Kan

Hiroko Katagiri

Takuya Kitamura

Hideaki Hasegawa

Ken Nakagawa

Yuta Isobe

Shunsuke Mizukoshi

Wataru Takahashi

Kazuhiro Doda

Seiji Saito

Satoshi Nishida

Kensuke Umeda

Ai Suzuki

Takashi Shimada

Shingo Ito

Michio Uchida

Tomonori Matsunaga

Shigeru Hoashi

Kenji Kanari

Takamitsu Soda

Hiroko Yokoyama

Eiichi Hamana

Shimpei Ishikawa

Kazuo Kishino

Motoki Adachi

Yuichiro Inaba

Takumi Furukawa

Akeshi Asaka

Kohei Okayasu

Satoru Motohashi

Shunsuke Matsushita

Shuhei Tokiwa

Masahito Omata

Hideo Kihara

Kuniaki Kasuga

Ken Yokoyama

Hiroyuki Kadowaki

Ryosuke Kanai

Shoji Umehara

Yusuke Baba

Tomoya Kuruma

Masayuki Onuma

Satoshi Takami

In an image forming apparatus, in which: a charging member charges an image bearing member; an exposure unit exposes a surface of the image bearing member to develop an electrostatic latent image; and a developer image on the image bearing member is transferred onto a recording material. A control portion is capable of executing a first operation mode for rotating the image bearing member at a first peripheral velocity, the first operation mode being a mode in which the exposure unit exposes the surface of the image bearing member with a first exposure intensity, and a second operation mode for rotating the image bearing member at a second peripheral velocity lower than the first peripheral velocity, the second operation mode being a mode in which the exposure unit exposes the surface of the image bearing member with a second exposure intensity higher than the first exposure intensity.

Image forming apparatus

An image forming apparatus includes a rotatable image bearing member and a rotatable developing member to carry developer made up of toner particles and carrier particles adhered to surfaces of the toner particles. Where a pressing force pressing the developing member against the image bearing member is F1, a total number of the carrier particles interposed between the toner particles and the image bearing member is N1, and an adhesion Ft between a carrier particle and a toner particle, measured when the carrier particle is pressed against the toner particle with F1/N1 that is a pressing force per unit carrier particle, and an adhesion Fdr1 between the carrier particle and the image bearing member, measured when the carrier particle is pressed against the image bearing member with F1/N1, satisfy Ft≤Fdr1.

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.

An image forming apparatus includes a rotatable image bearing member, a developing unit to develop an electrostatic latent image at a developing portion, a transfer unit to transfer a developer image to a recording member at a transfer portion; and a brush provided with a plurality of fibers 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. An average contacting pressure of the brush per one fiber to the image bearing member is smaller than a depositing force of the developer not transferred to the recording member to the image bearing member. As the brush in a state of not in contact with the image bearing member is viewed from a free end side of the fibers, an average number of the fibers included in a circumference of a diameter of 100 μm is more than one.

Image forming apparatus with fiber brush

An image forming apparatus to perform an image forming operation for forming an image on a transfer material includes a photosensitive drum, a moving member, a detection unit, and a control unit. The detection unit detect information about a first movement in which the moving member moves from an open position to a shielding position or a second movement in which the moving member moves from the shielding position to the open position. During execution of a non-image forming operation, the control unit executes a multiple switching operation for performing a switching operation a plurality of times. The switching operation is an operation in which the control unit stops the photosensitive drum from being driven and then rotatably re-drives the photosensitive drum. Where the detection unit detects the information about the first movement or the second movement, the control unit performs control to execute the multiple switching operation.

An image forming apparatus to perform an image forming operation of forming an image on a transferred material includes a photosensitive drum, an exposure unit, a transfer member to form a transfer portion, a transfer voltage applying unit to apply a transfer voltage, an opening/closing member, a detection unit to detect information regarding a first movement or a second movement, and a control unit to execute the image forming operation and a non-image forming operation. Where the detection unit detects the first and second movements, in the non-image forming operation, the control unit rotates the photosensitive drum at least one rotation in a state where a surface of the photosensitive drum is exposed with light by the exposure unit and the transfer voltage is applied so an electrostatic force that causes toner charged to a positive polarity to be attracted to the transfer member is generated in the transfer portion.

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.

An image forming apparatus includes a charging unit that charges an image bearing member, a developing unit that forms a toner image on an latent image formed on the image bearing member, a transfer unit that transfers the toner image onto a transfer material, a charge neutralizer that neutralizes a charge of the image bearing member downstream of a transfer portion and upstream of a charging portion in a rotating direction of the image bearing member, a conductive collecting unit that collects a material adhering on the image bearing member downstream of the transfer portion and upstream of the charging portion, wherein the developing unit collects residual toner on the image bearing member, an voltage application unit sets a potential difference between the voltage applied to the collecting unit and the surface electric potential of the image bearing member not more than a discharge threshold.

Image forming apparatus with brush that collects material adhered to surface of image bearing member and that includes brush portion including threads having specified thread density

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 forms an image on a recording medium and includes a rotatable image bearing member, and a rotatable developer carrying member that carries a developer, forms a developing portion by contacting the image bearing member, and forms a developer image on a surface of the image bearing member by supplying the developer to an electrostatic latent image formed on the surface of the image bearing member in the developing portion. After performing an image forming operation, a controller controls driving of the image bearing member and the developer carrying member to perform a rotation operation for rotating the image bearing member with rotation of the developer carrying member stopped in a state where an amount of carried developer in the developing portion during the rotation operation is smaller than the amount of carried developer in the developing portion during the image forming operation.

Image forming apparatus that removes residual toner with developer carrying member

An image forming apparatus includes a photosensitive member, a charging member, an electrostatic image forming portion, a developing member, a transfer member, a transfer voltage source, a brush member, a brush voltage source, and a controller capable of executing a cleaning operation. The controller carries out control so that the cleaning operation includes a first operation in which a potential difference is formed between the transfer member and the photosensitive member so that toner charged to a normal charge polarity is moved from the transfer member toward the photosensitive member, and a second operation in which a potential difference is formed between the brush member and the photosensitive member so that the toner charged to the normal charge polarity is moved from the photosensitive member toward the brush member.

Image forming apparatus capable of suppressing an improper charge resulting from toner being moved from a transfer member to a photosensitive 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

A control unit performs control to make a direction of an electric field generated in a first area of an image carrier forming a transfer portion during image forming operation, relative to a voltage applied to a brush member in a state where the first area passes through a contact portion, different from a direction of an electric field generated in a second area of the image carrier forming the contact portion, relative to the voltage applied to the brush member during a period when operation is shifted from first operation in which the image carrier is rotated at a first speed to second operation in which the image carrier is rotated at a second speed different from the first speed, during non-image forming operation different from the image forming operation.

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Kawasaki, Japan

Shuichi Tetsuno