Canon Kabushiki Kaisha

Takuya Oka

Yoshihiro Mitsui

Yasukazu Ikami

Issei Imamura

Yuichiro Hirata

Ryohei Tsutsumi

Kodai Hayashi

Shinichi Agata

Masato Tanabe

Takatoshi Hamada

Shuhei Kawasaki

Masahito Kato

Keitaro Nakata

Koichi Ooishi

Yu Akiba

Harunobu Maeda

Kentaro Yamawaki

Takayoshi Kihara

Shunsuke Matsushita

Akinobu Saito

A restricting member includes a blade portion and a supporting portion. A contact portion is provided at the blade portion, and, in a cross section orthogonal to a longitudinal direction, the contact portion includes a first portion extending in a first direction and a second portion extending toward a free end from an end of the first portion and extending in a second direction. When a region demarcated by connecting an intersection point, the end of the first portion, and an end of the second portion by a straight line is defined as a first region, the intersection point being where an imaginary line intersects an extension line of the first portion in the first direction, an area of the first region is smaller on a longitudinal end portion than on a longitudinal central portion of the blade portion.

Restricting member, developing device, process cartridge, and image forming apparatus

An image forming apparatus includes an image bearing member, a developer bearing member, a drive unit for driving the image bearing member and the developer bearing member in varied peripheral speeds, a control unit, a developing voltage application unit, a supply member for supplying a developer to the developer bearing member, and a supply member voltage application unit. The control unit executes a first image forming mode in which a rotational peripheral speed ratio between surface movement speeds of the developer bearing member and the image bearing member is not greater than 1 and a second image forming mode in which the rotational peripheral speed ratio is greater than 1, and the control unit controls the drive unit so that a difference between developing voltage and supply voltage is greater in the second image forming mode than that in the first image forming mode.

Image forming apparatus

A developing device includes a stirring member including a flexible sheet member having a first sheet portion and a second sheet portion overlapping each other with respect to a thickness direction of the sheet member. With respect to a lateral direction of the sheet member which is a direction from a fixed end fixed to a rotating shaft portion to the free end, a length of the first sheet portion is longer than a length of the second sheet portion, and when the stirring member is rotated, a free end of the first sheet portion is capable of contacting an inner wall surface of a toner accommodation chamber. The sheet member is provided with a through hole penetrating in a thickness direction of the sheet member in a region where the first sheet portion and the second sheet portion overlap each other.

Developing device, cartridge, image forming apparatus

A cartridge mountable in an apparatus main body of an image forming apparatus, the cartridge includes a development roller, a frame member including a development chamber, a developer containing chamber, and a first opening portion, the developer containing chamber including an inner wall and a second opening portion, a stirring member including a stirring shaft and a sheet, and a conveyance member driven in such a manner that the developer is replenished into the developer containing chamber through the second opening portion, wherein the sheet is rotated in contact with the inner wall in such a manner that, after the sheet is elastically deformed by contact with a portion of the inner wall, at least a part of the elastic deformation is restored, and wherein the conveyance member is being driven at a timing when the sheet passes through the front side.

Development cartridge

A developing device includes a frame having an accommodation chamber where a developer is accommodated, and a replenishing port replenishing a developer to the accommodation chamber from outside, and a stirring member stirring the developer in the accommodation chamber. The stirring member includes a rotating shaft portion rotatably supported by the frame and a sheet member having one end fixed to the rotating shaft portion and another end as a free end and being rotatable with the rotating shaft portion. When the stirring member is rotated, the free end of the sheet member is capable of contacting an inner wall surface of the accommodation chamber in which the replenishing port is formed, and a through hole penetrating in a thickness direction of the sheet member is provided in a region of the sheet member that comes into contact with the inner wall surface of the accommodation chamber.

An image forming apparatus includes a detection member configured to detect a conveyance state of a recording medium, a control unit configured to sequentially execute a first operation for continuously executing a rotation operation of an image bearing member and an intermediate transfer member without stopping them when the detection member detects a failure, and a second operation for stopping the rotation operation of the image bearing member when the surface of the image bearing member is moved by a predetermined distance through the rotation operation of the image bearing member after the failure is detected.

Provided are an image bearing member, a developer bearing member, and a cleaning member. A fixation layer, including at least one of an organosilicon polymer and inorganic particles, is provided on a surface of the developer borne on the developer bearing member, and a fixation percentage of the fixation layer is 85% or greater. The image bearing member and the developer bearing member are rotationally driven such that, a surface of the image bearing member and a surface of the developer bearing member move in opposite directions from each other at a contact portion where the image bearing member and the developer bearing member are in contact with each other.

Process cartridge providing fixation layer to developer on image bearing member and image forming apparatus

An image forming apparatus in which when toner remaining on a development roller in an area from a developer nip to a regulating blade disposed upstream of a rotation direction of the development roller during a stoppage of the image forming apparatus passes through the developer nip, a bias is applied so that the toner is drawn to the development roller, and a relative speed difference between the photosensitive drum and the development roller is created so as to be larger than the that during an image forming operation.

Image forming apparatus to perform an activation control using a developing bias applying member and a speed control unit

A developer borne on a developer bearing member includes a toner, the toner has a Martens hardness of at least 200 MPa and not more than 1100 MPa when measured under a condition of a maximum load of 2.0&#xd7;10N, and where a contact pressure of a regulating member that regulates the developer borne on the developer bearing member against the surface of the developer bearing member is denoted by N (gf/mm) and a contact pressure of a supplying member that supplies the developer to the developer bearing member against the surface of the developer bearing member is denoted by D (gf/mm), the following expressions are satisfied: D+2&#xd7;N&#x2212;6&#x2265;0, 1.5&#x2264;N&#x2264;4.5, and 2.0&#x2264;D&#x2264;4.5.

Developing device, process cartridge and image forming apparatus

A developing device includes a developer carrying member, a developing frame, and a regulating member. The regulating member includes a curved surface portion contactable to a surface of the developer carrying member, and satisfies the following relationships: 200 MPa&#x2264;HM&#x2264;1100 MPa, and 0.08 mm&#x2264;Rb&#x2264;0.3 mm, where HM is a Martens hardness of toner contained in the developer under a maximum load of 2.0&#xd7;10N, and Rb is a radius of curvature of the curved surface portion.

A developer on a developer bearing member includes a toner having a toner particle including a binder resin and an inorganic particle present on the surface of the toner particle. A fixing ratio of the inorganic particle to the surface of the toner particle is 80% or more. The aspect ratio of the toner is 0.90 or more. Where a contact pressure of a regulating member, which regulates the developer on the developer bearing member, against the developer bearing member is denoted by N (gf/mm) and a contact pressure of the supplying member, which is in contact with the developer bearing member and supplies the developer to developer bearing member, against the developer bearing member is denoted by D (gf/mm), the following expressions are satisfied: D+2&#xd7;N&#x2212;6&#x2265;0, 1.5&#x2264;N&#x2264;4.0, and 2.0&#x2264;D&#x2264;3.5.

Developing device, process cartridge, and image forming apparatus

A cartridge includes a cleaning member configured to retain specific particles having a smaller equivalent sphere diameter than toner particles at a contact region. The specific particles contain an organosilicon polymer having a partial structure represented by R&#x2014;SiO, wherein R represents an alkyl group having 1 to 6 carbon atoms. The atomic concentration dSi of silicon in the specific particles satisfies 1.0 atomic %&#x2264;dSi&#x2264;29.0 atomic % when the total atomic concentration of silicon, oxygen, and carbon in the specific particles is measured to be 100.0 atomic % by electron spectroscopy for chemical analysis (ESCA). Also, the specific particles satisfy L/L&#x2264;3/4 or L/L&#x2265;4/3 when assuming that the specific particles have three lengths L, L, and Lin three axis directions in a three-dimensional coordinate system, wherein Lis the longest one of the three lengths, in an average value of a unit volume.

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Yokohama, Japan

Takuya Oka