Canon Kabushiki Kaisha

Shunsuke Matsushita

Hisashi Taniguchi

Yoshihiro Mitsui

Shuhei Kawasaki

Atsushi Toda

Kodai Hayashi

Bunro Noguchi

Shuichi Tetsuno

Taichi Sato

Toshihiko Takayama

Nobuo Oshima

Takayoshi Kihara

Naoki Fukushima

Yasukazu Ikami

Kazuhiro Yamauchi

Yoshitaka Suzumura

Hiroyuki Tomono

Katsuyuki Nonaka

Yuichiro Hirata

Masahiro Kurachi

Shuhei Tokiwa

Shinichi Hagiwara

Osamu Matsushita

Taku Watanabe

Nobuyoshi Yoshida

Issei Imamura

Takuya Oka

Yosuke Kishi

Kosuke Ikada

Takuya Mizuguchi

Shimpei Ishikawa

Mikihiko Hamada

Hirokazu Fujino

Hiroko Katagiri

Hirokazu Okugawa

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 about a rotational axis extending in the axial direction, a charging member, an accommodating portion accommodating toner charged to a predetermined polarity; a developing member, a transfer portion, a static eliminating portion, and a collecting member. In the axial direction, when A is a eliminating width with which the eliminating portion discharges the surface of the image bearing member, B is an effective charging width with which the charging member charges the surface, and C is a collection contacting width with which the collecting member contacts the surface, the formula A<B<C is satisfied. In the axial direction, a surface potential of the surface in an area outside the effective charging width, inside the collection contacting width and in contact with the collecting member is a first potential larger than 0V in the same polarity direction as the predetermined polarity.

An image forming apparatus includes an image bearing member, a charging member, a development member, a developer accommodating portion, a first acquiring portion which acquires developer amount information related to an amount of the developer accommodated in the developer accommodating portion, a second acquiring portion which acquires development drive information related to a movement distance of a surface of the development member, and a control portion which is capable of executing a first mode and a second mode, whose frequency of driving the development member lower than that of the first mode, as an image forming mode. The control portion proposes or determines a change from the first mode to the second mode of the image forming mode on the basis of the developer amount information and the development drive information.

An image forming apparatus includes a controller to i) notify first notification on an exchange of a developer supply container in a case the developer in the supply container is decreased in amount by being supplied from the supply container to a developer accommodating portion and then the developer amount of the developer in the supply container indicated by the first developer amount information reaches a predetermined developer amount, ii) to execute an operation until the supply container connected to a developing unit is exchanged after the first notification, and iii) to notify second notification notifying an end of the operation in a case that after the operation is started, a use amount of the developer from the developing unit indicated by the second developer amount information reaches the usable amount. In addition, a developing setting portion sets the usable amount depending on exchange number information and print ratio information.

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 includes a photosensitive drum, a development roller configured to supply developer to the photosensitive drum, a transfer roller configured to transfer a developer image formed on the photosensitive drum to a recording material, and a cleaning roller being in contact with the photosensitive drum, configured to clean a part of the recording material adhered to the photosensitive drum, wherein the diameter of the transfer roller is greater than the diameter of the development roller and the diameter of the cleaning roller is greater than the diameter of the development roller.

An image forming apparatus includes a photosensitive drum, a development roller configured to supply developer to the photosensitive drum, a transfer roller configured to transfer a developer image formed on the photosensitive drum to a recording material, and a cleaning roller being in contact with the photosensitive drum, configured to clean a part of the recording material adhered to the photosensitive drum, wherein a diameter of the transfer roller is greater than a diameter of the development roller and the diameter of the transfer roller is greater than a diameter of the cleaning roller.

Image forming apparatus capable of suppressing image defects caused by paper dust

An image forming apparatus detects a first current value and a second current value of currents flowing between an image bearing member and a developer carrying member. When a difference between the detected first current value and the detected second current value exceeds a threshold in a state in which the image bearing member and the developer carrying member are rotated and a first developing voltage is applied to the developer carrying member, a controller controls AC voltage applied to the developer carrying member.

Non-contact developer bias voltage control for image forming apparatus

An electrophotographic apparatus comprising an electrophotographic photosensitive member, a charging device and a developing device, wherein the charging device comprises a conductive member arranged to be capable of contacting the electrophotographic photosensitive member, a conductive layer of the conductive member comprises a matrix domain structure, at least a part of the domains Dt is exposed at the conductive member outer surface, the matrix has a volume resistivity R1 of larger than 1.00&#xd7;10&#x3a9;&#xb7;cm, the domains Dt has a volume resistivity of smaller than R1, the developing device comprises the toner, domains Dc formed of the crystalline material exist in a cross section of the toner, distances between adjacent wall surfaces of the domains Dc is from 30 to 1,100 nm, and a weight-average particle diameter D4 of the toner and distances Dms between adjacent wall surfaces between the domains Dt satisfies D4&#x2265;Dms.

Electrophotographic apparatus, process cartridge, and cartridge set

An image forming apparatus includes a photosensitive member, a charging member for charging the photosensitive member, a cleaning member that comes into contact with the charging member and moves relative to the charging member to clean the charging member, an opening/closing member for exposing an inside of the apparatus, and a driving mechanism that moves the charging member and the cleaning member relative to each other in association with opening/closing of the opening/closing member.

Image forming apparatus and cartridge

An image forming apparatus includes a rotatable image bearing member, a charging member, a charging voltage applying portion, a developer carrying member, a developing voltage applying portion, a detecting portion, and a controller. In a state in which the charging voltage is applied to the charging member, the controller controls the detecting portion so as to detect whether or not a change amount between a current value detected by the detecting portion when the surface of the image bearing member opposing the developer carrying member before application of the developing voltage passes through an opposing portion where the charging member and the image bearing member are opposed to each other and a current value detected by the detecting portion when the surface of the image bearing member opposing the developer carrying member after the application of the developing voltage passes through the opposing portion is a threshold or more.

Image forming apparatus comprising leakage detection

An image forming apparatus includes an image bearing member, a charging member for charging the image bearing member, an exposure unit for exposing the charged surface of the image bearing member, a developing apparatus that supplies a developer containing a toner particle and an external additive having an opposite charging polarity to the regular charging polarity of the toner particle to the image bearing member, a cleaning member for removing the developer from the image bearing member, a transfer member for transferring a developer image on the image bearing member onto a transfer subject material, and a voltage application unit for applying a voltage to the transfer member. During an image non-formation period as a lubrication operation to the cleaning member, (i) the developer is supplied to the image bearing member, and (ii) a voltage having an identical polarity to a voltage applied during the image formation operation is applied.

A process cartridge includes a developing device that supplies developer to a photosensitive member and an elastic portion that cleans a peripheral surface of the photosensitive member. Multiple grooves are formed side by side in a generatrix direction on the peripheral surface. The developer contains a toner including a toner particle and an organosilicon polymer having a structure represented by R&#x2014;SiOcovering the toner particle surface, where R represents a hydrocarbon group having at least 1 and not more than 6 carbon atoms. When a penetration amount of the elastic portion with respect to the photosensitive member is set as &#x3b4; (mm), and a fixing rate of the organosilicon polymer on the surface of the toner particle is set as &#x3b1; (%), &#x3b4;&#x2264;0.02&#xd7;&#x3b1;&#x2212;0.4 is satisfied.

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Yokohama, Japan

Shunsuke Matsushita