Canon Kabushiki Kaisha

Koji An

Shinji Katagiri

Takuya Kitamura

Kazunari Hagiwara

Shuichi Tetsuno

Takashi Mukai

Takaaki Shinkawa

Hiroko Katagiri

Wataru Takahashi

Takayuki Tanaka

Jun Miura

Keisuke Ishizumi

Tomonori Matsunaga

Takashi Hiramatsu

Shohei Ishio

Hiroko Yokoyama

Kazuhiro Doda

Tsuguhiro Yoshida

Toru Imaizumi

Kohei Wakatsu

Kenichi Ogawa

Takashi Narahara

Takaaki Akamatsu

Takeshi Shinji

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.

Image forming apparatus

An image forming apparatus includes an image bearing member, a transfer member, a supplying member for supplying a protective agent applied onto a surface of the transfer member, and a controller capable of controlling the supplying member. In a state in which the transfer member contacts the image bearing member during non-image formation outside of image formation in which the toner image is transferred from the image bearing member onto the recording material, the controller carries out control so that an operation in an application mode, in which the protective agent supplied from the supplying member is applied onto the surface of the transfer member, is executed.

Image forming apparatus which supplies yellow toner as protective agent to secondary transfer member

An image forming apparatus includes an image bearing member, a transfer member, a power source, a detecting portion, a controller, an environment detecting portion, and a contact member. In a case that an absolute water content acquired on the basis of environmental information is a predetermined threshold or more, the controller sets a limit voltage on the basis of a detection result of the detecting portion in a state in which the recording material is absent in a transfer portion, and the controller controls the power source so that an absolute value of a voltage applied from the power source to the transfer member during contact of the recording material with the transfer member and the contact member is an absolute value of the limit voltage or less.

Image forming apparatus having grounded fixing member

In an image forming apparatus including a transfer member that primarily transfers a developer image from an image bearing member onto an intermediate transfer belt by applying an electric current to an intermediate transfer belt in a circumferential direction, a control unit which executes a first mode in which to rotate the intermediate transfer belt and a second mode in which to rotate the intermediate transfer belt at a rotation speed higher than that in the first mode. The control unit performs control such that an absolute value of a second voltage to be applied to the transfer member in a case of performing primary transfer in the second mode is less than an absolute value of a first voltage to be applied to the transfer member in a case of performing the primary transfer in the first mode.

Image forming apparatus to suppress scattering of toner

An image forming apparatus includes first and second image forming portions, a power source portion, and a controller. The power source portion is constituted so that when the power source portion applies a charging voltage to a first charging member of the first image forming portion, the charging voltage is also applied to a second charging member of the second image forming portion. The controller carries out control so that a timing of a start of discharge of a first photosensitive drum in the first image forming portion is made earlier than a timing of a start of image formation by the first image forming portion and so that a timing of a start of discharge of a second photosensitive drum in the second image forming portion is made earlier than a timing of a start of image formation by the second image forming portion.

An image forming apparatus includes an image bearing member, a transfer member, an acquiring portion, an applying portion, and a controller. When a transfer voltage is subjected to constant-voltage control so that the transfer voltage applied to the transfer member by the applying portion is substantially constant, in a case that the transfer voltage, when a toner amount used for a toner image is a first toner amount, is a first voltage, the controller controls the applying portion so that the transfer voltage is a second voltage lower in absolute value than the first voltage in a case that the toner amount is a second toner amount greater than the first toner amount. The acquiring portion acquires toner amount information on the toner amount for each toner image transferred onto a single recording material.

An image forming operation forms an image on a transfer target in a state in which a developing member is located at a first position where a developer is supplied to an image bearing member and a first charging voltage is applied to a charging unit. The image forming operation is followed by: a first rotating operation of rotating the image bearing member in a state in which the developing member is located at the first position and a second charging voltage smaller in absolute value than the first charging voltage is applied; and a second rotating operation of rotating the image bearing member in a state in which the developing member is located at a second position where the developer is not supplied to the image bearing member and a third charging voltage smaller in absolute value than the second charging voltage is applied.

Image forming apparatus and control method, that control charging voltage according to positions of developing roller

An image forming apparatus includes an intermediate transfer belt, an outer roller, a power source, and a regulation member. The outer roller transfers a toner image onto a recording material. The power source applies a voltage to the outer roller. The regulation member regulates orientation of the recording material. Information is acquired regarding a timing at which orientation of a recording material first portion, passing through the transfer portion that is located between the outer roller and the regulation member, can change to move closer to the intermediate transfer belt. Based on the acquired information, a transfer voltage target value for transfer onto the recording material is changed between a first target value of a period anterior to the timing and a second target value of a period posterior to the timing that is larger in absolute value than the first target value.

Image forming apparatus to control transfer voltage for secondary transfer to recording material

An image forming apparatus includes an image bearing member, an intermediate transfer belt, and a contact member. The intermediate transfer belt includes a base layer, a surface layer formed on an outside of the base layer, and an inner surface layer formed on an inner side of the base layer. A position at which the contact member and the intermediate transfer belt contact is arranged on a downstream side of the intermediate transfer belt in a rotation direction of the intermediate transfer belt. Rv>Rs1 and Rs2>Rs1, and Rs2/Rv≤40 are satisfied where Rv (Ω) is a volume resistance value of the intermediate transfer belt in a thickness direction, Rs1 (Ω) is a first surface resistance value of the inner surface layer side in a surface direction, and Rs2 (Ω) is a second surface resistance value on the surface layer side in a surface direction.

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 F, a total number of the carrier particles interposed between the toner particles and the image bearing member is N, and an adhesion Ft between a carrier particle and a toner particle, measured when the carrier particle is pressed against the toner particle with F/Nthat is a pressing force per unit carrier particle, and an adhesion Fdrbetween the carrier particle and the image bearing member, measured when the carrier particle is pressed against the image bearing member with F/N, satisfy Ft≤Fdr

Image forming apparatus controlling voltage applied to transfer member

Image forming apparatus providing variable transfer voltage based on transfer mode

When a new development device is mounted, a control unit of an image forming apparatus identifies a development device type. When an identification result corresponds to a first development device containing a first amount of developer, an agitation member operates in a first mode. When the identification result corresponds to a second development device containing a second amount of developer higher than the first amount, the agitation member operates in a second mode. A second operation amount of the agitation member in the second mode is higher than a first operation amount of the agitation member in the first mode. A developer containing chamber of the development device is provided with a discharge opening from which the developer is discharged. The operations in the first and second modes are performed after a sealing member sealing the discharge opening is removed and also before a normal image forming process is executed.

A process cartridge includes a developer carrier including a dielectric portion and a conductive portion on a surface thereof, a regulation member, and an image carrier disposed so as to come into contact with the developer carrier. The developer carrier and the image carrier are rotationally driven such that a surface of the developer carrier and a surface of the image carrier move at linear velocities different from each other at a contact portion, and the developer remaining on the image carrier after the developer image is transferred from the image carrier, is collected by the developer carrier at the contact portion.

Growing community of inventors

Tokyo, Japan

Koji An