Canon Kabushiki Kaisha

Ryosuke Kanai

Yosuke Kishi

Masao Uyama

Makoto Fukatsu

Kuniaki Tamagaki

Yousuke Kishi

Shuichi Tetsuno

Tomoo Akizuki

Hiroki Tanaka

Kohei Matsuda

Satoshi Sunahara

Satoru Inami

Kazuhisa Shida

Seiichi Shinohara

Yuta Isobe

Takahiro Ikeda

Shunsuke Mizukoshi

Motonari Ito

Akihisa Matsukawa

Nobuyoshi Yoshida

Makoto Tokudome

Takashi Koyanagi

Koichiro Takashima

Kenji Shindo

Hideto Oka

An image forming apparatus includes a developer carrying member that bears and conveys developer. The developer carrying member has at least a base and a surface layer, with the surface layer having an electron donating portion that mainly donates charge to the developer when the developer and the surface layer make frictional contact to exchange charge and an electron accepting portion that mainly accepts charge from the developer when the developer and the surface layer makes frictional contact to exchange charge. A controller applies an AC voltage to the developer carrying member during a period in which an image forming operation is not performed and the developer carrying member is driven, with the AC voltage being different from that applied during an image forming period, and a rotating speed of the developer carrying member during a non-image forming period is slower than that during an image forming period.

Image forming apparatus having toner charging

During non-image formation, an exposure unit exposes an image formable region on the image bearing member surface charged by a charging member to light, and, in a state where toner is able to be supplied from a developing member to the image bearing member, during a period from when a developing voltage starts to be changed from a first developing voltage to a second developing voltage smaller than the first developing voltage until the developing voltage is completed to be changed to the second developing voltage. A controller controls the exposure unit so that, after the image bearing member surface exposed to light with a first exposure amount by the exposure unit passes through a development portion, the image bearing member surface exposed to light with a second exposure amount smaller than the first exposure amount by the exposure unit passes through the development portion.

Image forming apparatus with fog suppression feature

An image forming apparatus includes: an image bearing member to rotate; a charging member to charge a surface of the image bearing member; a charging voltage applying portion to apply an alternating-current voltage having a predetermined charging frequency to the charging member; and an exposing portion to perform image exposure and background exposure. A plurality of modes are settable for the image forming apparatus, and the plurality of image forming modes include image forming modes different in a background potential difference which is a potential difference between a surface potential of the image bearing member after the surface of the image bearing member is charged and before the charged surface is exposed by the exposing portion and a surface potential of a portion of the surface of the image bearing member which has been subjected to the background exposure.

Image forming apparatus having a plurality of modes different in background potential difference

An image forming apparatus is provided which can reduce occurrence of unusual noise. The image forming apparatus includes a driving motor configured to drive a developer bearing member and a control unit which can control the driving motor between a first driving speed and a second driving speed higher than the first driving speed. In a case where the first driving speed is equal to the driving speed of the image forming operation, the control unit controls the driving motor to drive at the second driving speed while an unsealing operation is being performed.

Image forming apparatus and control method wherein a developer bearing member is driven at various speeds

A developing device includes a developer bearing member that bears a developer, a developer regulating member having a regulation portion comprised of an elastic member contacting the developer bearing member, and a supporting portion supporting the regulation portion, a longitudinal direction of the regulation portion being along that of the developer bearing member, the regulation portion having a base portion and tip portion, the base portion being an end portion on a side of a portion connected with the supporting portion in a transverse direction, the base portion being opposite to the tip portion, the tip portion being disposed on an upstream side in a moving direction of the developer bearing member, the developer regulating member regulating a developer on the developer bearing member, and a sealing member contacting a regulation portion's surface, the surface being on an opposite side of the regulation portion to the developer bearing member.

Developing device, developer regulating process, and image forming device

An image forming apparatus, including: a rotatable image bearing member; a developing unit configured to supply a developer onto the image bearing member; a transfer unit configured to transfer the developer on the image bearing member to a recording medium by a transfer voltage being applied to the transfer unit by a voltage applying unit; and a cleaning unit configured to remove the developer on the image bearing member, wherein when the apparatus stops an image forming operation halfway, the apparatus executes a recovery operation in which the image bearing member is rotated while the voltage applying unit applies a voltage to the transfer unit so that a part of the developer remaining on the image bearing member is once transferred from the image bearing member to the transfer unit, transferred again from the transfer unit to the image bearing member, and then removed by the cleaning unit.

Image forming apparatus with cleaning unit

A developer container includes: an accommodating chamber, provided with an opening for permitting discharge of a developer; and developer feeding means. The developer feeding means includes: a rotatable member; a developer feeding member fixed on the rotatable member; a sealing member for opening the opening by the rotation of the rotatable member, wherein one end portion thereof is fixed on the rotatable member and the other end portion thereof is provided so as to seal the opening; and a regulating portion for regulating the sealing member, which is wound about the rotatable member after the opening is opened by the rotation of the rotatable member, so as to expose a feeding surface of the developer feeding member.

Developer container, developing device, process cartridge and image forming apparatus

A detecting system for detecting a developer remainder in a developer container accommodating a developer to be used for developing an electrostatic latent image formed on an image bearing member. The detecting system includes first, second and third electrode members provided in the developer container, an AC voltage source for applying an AC voltage to the third electrode member, a first electrostatic capacity detector for detecting a first electrostatic capacity between the first electrode member and the third electrode member, and a second electrostatic capacity detector for detecting a second electrostatic capacity between the second electrode member and the third electrode member. In addition, a developer remainder detector corrects the first electrostatic capacity on the basis of the second electrostatic capacity and detects a developer remainder of the developer container from a result of correction of the first electrostatic capacity. The first electrostatic capacity is corrected on the basis of the second electrostatic capacity.

Developer remainder amount detection system and image forming apparatus

An image forming apparatus includes a conductive member paired with one of a developer carrying member and an image bearing member to form a capacitor. A contact-separation member assumes a first position for bringing the developer carrying member into contact with the image bearing member and a second position for separating the developer carrying member from the image bearing member. A detecting unit detects a value relating to a capacitance of the capacitor when a voltage is applied to the capacitor, and a control unit detects whether or not the image forming apparatus is ready for image formation by comparing a first detected result and a second detected result to each other. The first detected result is detected when the contact-separation member assumes the first position, and the second detected result is detected when the contact-separation member assumes the second position.

Image forming apparatus having capacitance detection

A cleaning device includes a fixing portion provided on a frame, a cleaning member, and an accommodating portion. The cleaning member includes a blade portion contacted to an image bearing member (drum) and a supporting member. The supporting member includes one end portion where the blade portion is provided, another end portion including a portion-to-be-fixed for being fixed at the fixing portion, and a bent portion between the one end portion and the other end portion in a side remote from a surface of the drum toward an outside with respect to a line connecting the portion-to-be-fixed and a contact portion where the blade portion is contacted to the drum. The portion-to-be-fixed is provided downstream of the contact portion with respect to movement direction of the drum. Between the frame and the other end portion, a gap for permitting elastic deformation of the other end portion is provided.

Cleaning device, process cartridge and image forming apparatus

A blade-like charging member comprises a charging portion, a non-charging portion, and an electrode portion. The non-charging portion is capable of contacting the image bearing member while maintaining an electrically dischargeable gap therebetween. To prevent electric discharge between the non-charging portion and the surface of the image bearing member, at least part of the non-charging portion is made of material having a higher resistance than that of the charging portion. The non-charging portion contacts and slides on the surface of the image bearing member over a range that exceeds the length of the charging portion. A shortest distance between the discharge position and an end portion of the electrode portion with respect to a longitudinal direction of the image bearing member is longer than a shortest distance between the discharge position and a central portion of the electrode portion with respect to the longitudinal direction of the image bearing member.

Charging member and image forming apparatus

An image forming apparatus includes a standard exposure device () adjusted to emit light of a predetermined light quantity, and a control device configured to determine light quantity of the pre-charge exposure device in an image-forming period based on the first and the second charging current values, wherein first charging current value is detected when an area on a photosensitive member surface is recharged by the contact charging member, in a case where the photosensitive member is exposed by turning on the standard exposure device without turning on a pre-charge exposure device, and second charging current value is detected when an area on the photosensitive member surface is recharged by the contact charging member, in a case where the photosensitive member charged by applying a predetermined voltage by the contact charging member is exposed by turning on the pre-charge exposure device without turning on the standard exposure device.

Image forming apparatus

An inexpensive image forming apparatus, which can suppress a ghost to obtain an image maintaining satisfactory density and gradations for a long time. The apparatus including an electrophotographic photosensitive member, a contact charger in contact with the photosensitive member for charging the photosensitive member, a charging voltage applying device for applying direct current voltage to the contact charger, a charging current detector for detecting electric current flowing through the contact charger, a pre-exposure device for exposing the photosensitive member to light to remove residual charge on the photosensitive member, and a pre-exposure light amount controller for controlling an exposure light amount of the pre-exposure device in image formation based on the results of detection by the charging current detector when the exposure light amount of the pre-exposure device is changed with direct current voltage applied from the charging voltage applying device to the contact charger during non-image formation.

Image forming apparatus with a pre-exposure light control feature

A process cartridge is detachably mountable to an image forming apparatus. The process cartridge includes an image bearing member, a developing member for developing an electrostatic latent image formed on a surface of the image bearing member and a cleaning member having a blade contacted to the image bearing member along a longitudinal direction of the image bearing member to remove the developer from the surface of the image bearing member. The cleaning member has a processed portion containing an isocyanate compound at each of longitudinal end portions of the blade, wherein a longitudinally inside end of the processed portion is disposed longitudinally inside a developer carryable region of the developing member which is capable of carrying the developer.

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Kawasaki, Japan

Ryosuke Kanai