Canon Kabushiki Kaisha

Kabushiki Kaisha Meidensha

Nobuo Oshima

Takayuki Namiki

Takashi Mukai

Kuniaki Tamagaki

Hideaki Hasegawa

Norihito Naito

Satoru Motohashi

Yasunao Otomo

Masahiro Yoshida

Jun Miura

Taichi Sato

Kohei Matsuda

Takayuki Kanazawa

Kazumi Yamauchi

Koichiro Takashima

Masanori Tanaka

Satoshi Sunahara

Yuta Isobe

Hiroki Tanaka

Takahiro Kawamoto

Takayoshi Kihara

Shunsuke Matsushita

Shuhei Tokiwa

Hideo Kihara

Akihisa Matsukawa

Katsuichi Abe

Yoshihiro Ogawa

Naoki Hayashi

Takuya Kitamura

Shigemi Kamoshida

Kazuhisa Shida

Shuhei Kawasaki

Shunsuke Mizukoshi

Akira Matsuyuki

Shinichi Fujie

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.

Image forming apparatus

An image forming apparatus includes a moving unit to move a developing roller, a driving portion to be capable of rotating the developing roller in either case where the developing roller is located in a contact position in contact with a photosensitive drum or a separated position separated from the photosensitive drum, an acquiring portion to acquire information on a rotation amount of the developing roller and a notifying portion. The acquiring portion corrects a first information, on the rotation amount of the developing roller in the contact position, to a third information by using a first correction coefficient, and corrects a second information, on the rotation amount of the developing roller in the separated position, to a fourth information by using a second correction coefficient. The notifying portion performs the notification on a lifetime of the developing roller based on the third and the fourth information.

An image forming apparatus includes a rotatable image bearing member, a developing member, a transfer member, and a brush contacting a surface of the image bearing member in a contact portion downstream of a transfer portion and upstream of a developing portion with respect to a rotational direction of the image bearing member. The toner which is not transferred onto a toner image receiving member is collected by the developing member. In a charging series, the toner is positioned on the same side as a normal charge polarity of the toner relative to the brush. In the contact portion, a maximum value of a contact pressure of 0.7 gf/mmor more and 3.5 gf/mmor less, a maximum contact area ratio is 18% or more and 74% or less, and a Clark-Evans index of the brush is 1 or more.

Brush having a higher contact pressure with an image bearing member at an upstream end of the brush and image forming apparatus

An image forming apparatus includes an image bearing member, a charging member, an exposure unit, a developing unit including a developer carrying member and a regulating member, a transfer member, a counting portion, a driving portion, and a controller. The controller carries out control so as to perform an image forming operation capable of forming a developer image, on the image bearing member, to be transferred onto a recording material and a non-image forming operation in which the developer image to be transferred onto the recording material is not formed on the image bearing member. Depending on each of count values in a plurality of regions acquired by the counting portion in a predetermined period, the controller controls the driving portion so as to change a rotation amount of the developer carrying member in a developing rotation operation for rotating the developer carrying member during the non-image forming operation.

An image forming apparatus includes a first image forming portion, a second image forming portion, a belt, a charging voltage applying portion, and a transfer voltage applying portion. With respect to a movement direction of a recording material, the first image forming portion is provided upstream of the second image forming portion. In an image forming operation, a potential difference between a first transfer voltage and a potential at a first transfer portion, which is formed on a first image bearing member and does not form the image, is greater than a potential difference between a second transfer voltage and a potential at a second transfer portion, which is formed on a second image bearing member and does not form an image.

Image forming apparatus with image bearing members having different surface layer thicknesses

Image forming apparatus capable of suppressing image defect due to foreign matter

An image forming apparatus includes a latent image forming portion configured to form a latent image on an image bearing member; a developing device including a container configured to store toner and a developing member configured to supply the toner to the latent image formed on the image bearing member to form a toner image; an environment sensor configured to detect environmental information related to an environment in which the developing device is placed; and a controller configured to control switching between a first mode and a second mode, in which a number of prints per unit time is less than that in the first mode. The controller is configured to perform switching from the first mode to the second mode based on an update value obtained by adding or subtracting over time an index value weighted in accordance with the environmental information detected by the environment sensor.

An image forming apparatus includes an image bearing member, a developer container, a developing portion, a replenishment port configured to allow replenishment of one-component developer from a replenishment container, a conveyance portion configured to convey the developer accepted for replenishment through the replenishment port toward the developing portion, a developer remainder amount detection portion whose output value changes on a basis of an amount of developer accommodated in the developer container. A controller changes a developer conveyance speed of the conveyance portion in a conveyance operation on a basis of the output value of the developer remainder amount detection portion, the conveyance operation being an operation of conveying developer toward the developing portion by the conveyance portion and is performed before the image forming operation is started.

Image forming apparatus having developer conveyance speed control

A development frame body includes a concave portion, which is projected in a direction along an upward direction of a gravitational direction, and which is located at a downstream side of a communication port and an upstream side of a replenishing port, the concave portion and the replenishing port overlap with each other in an axis direction of a shaft portion when viewed in a direction orthogonal to the axis direction, a relationship R&#x2264;L is satisfied, when a free length of the sheet portion is L and a distance from a rotation center of the shaft portion to an inner wall face is R, and slit portions are formed in a free end of the sheet portion so that a section of the free end of the sheet portion can enter the concave portion when an agitation member is rotated.

Development device, cartridge, and image forming apparatus

A cartridge is detachably provided to a main body of an image forming apparatus. The cartridge includes an image bearing member which is rotatable, a charging roller which contacts and charges the image bearing member, and a cleaning member which cleans the charging roller with the brush portion. In a section substantially orthogonal to a rotational axis of the charging roller, a contact point between a surface of the image bearing member and a tangent crossing a downstream end of an abutment region of the brush portion against the charging roller in a rotation direction of the charging roller among tangents to the image bearing member is vertically above a horizontal line passing through a center of the image bearing member, and an upstream end of the abutment region in the rotation direction of the charging roller is vertically above the downstream end in the rotation direction.

Cartridge having cleaning member and image forming apparatus including same

Provided is a developer container, including: a frame body having an opening; a sealing member configured to seal the opening; an unsealing member configured to unseal the opening by moving the sealing member and accommodated inside the frame body; and a part of the sealing member peelably bonded to an outer peripheral edge of the opening on an opposite side of the unsealing member with respect to the opening.

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

A developer container includes a frame, provided with an opening, for accommodating a developer; a sealing member, including a folded-back portion, for sealing the opening; and a sandwiching portion for sandwiching the folded-back portion of the sealing member. In a plane perpendicular to the opening, the sealing member is nonwelded in the sandwiching portion.

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

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Inagi, Japan

Nobuo Oshima