Canon Kabushiki Kaisha

Yuji Bessho

Masahiro Inoue

Takeshi Tomizawa

Koji Masuda

Haruhiko Omata

Makoto Saito

Atsushi Matsumoto

Tomoyuki Sakamaki

Yusuke Ishida

Tsuyoshi Watanabe

Tadashi Fukuda

Masayuki Tamaki

Masanori Akita

Yoshikuni Ito

Toshiyuki Yamada

Hiroki Takayanagi

Yoichi Kimura

Satoshi Tamura

Yoshikuni Itou

A repulsive magnetic field is formed in a section immediately upstream of a regulating blade, so that generation of a developing-agent stationary layer is suppressed or eliminated. Accordingly, a developing apparatus capable of stably maintaining the layer thickness of developing agent conveyed to a developing area for a long time is provided.

Developing apparatus

In a development device which develops an electrostatic image formed on a rotating photosensitive drum by applying a development bias to a development sleeve bearing a two-component developer, the development device includes a specific pattern determination portion which determines whether or not the electrostatic image includes a specific pattern. When the development device develops the specific pattern electrostatic image determined by the specific pattern determination portion, a potential difference between a development sleeve and a first non-image part of a predetermined range which is adjacent to the specific pattern electrostatic image and located on an upstream side in a photosensitive drum rotating direction is set smaller than a potential difference between the development sleeve and a second non-image part which is different from the first non-image part.

Image forming apparatus having a controller that controls a potential

An image forming apparatus includes an image forming section for forming an image on a recording material with transparent toner; a heater for heating a first image and a second image which are formed on the recording material by the image forming section as transparent images different in toner coverage per unit area; a glossiness detector for detecting glossiness of the first and second images after the first and second images are heated; and a correction section for correcting an image forming condition of the image forming section on the basis of a glossiness toner coverage characteristic obtained by a detection result of the detector.

Image forming apparatus capable of optimizing glossiness of image formed on recording material with transparent or white toner

An image forming apparatus includes a plurality of development units each using a developer including a toner and a carrier, a density detection unit configured to perform a density detection operation for detecting a density of a detection toner image formed by each of the plurality of development units, and a replenishment unit configured to perform a toner replenishment operation based on a result of the detection by the density detection unit. In the image forming apparatus, at least two of the plurality of development units use respective toners having different color depths in the same hue, and a frequency of the density detection operation using the development unit using a lighter color toner is higher than a frequency of the density detection operation using the development unit using a darker color toner.

Image forming apparatus

A developing device includes a developer-bearing member supporting developer for developing electrostatic images, a first chamber supplying the developer to the developer-bearing member, a second chamber below the first chamber, first and second communicating portions connecting the first and second chambers, a first carrying member carrying the developer in the first chamber in a first direction from the first communicating portion to the second communicating portion, a second carrying member carrying the developer in the second chamber in a second direction from the second communicating portion to the first communicating portion, and a partition between the first and second chambers. A bottom portion of the first chamber is inclined such that a downstream end thereof in the first direction is higher than the other end at a position where the bottom portion faces the developer-bearing member.

Developing device for developing images by adhering developer onto electrostatic images

An image forming apparatus which improves uneven gloss occurring at the step of fixing a transparent toner is provided with an image bearing member on which a latent image is formed, a transparent toner image forming device for forming a transparent toner image on the image bearing member, a transferring device for transferring the formed transparent toner image onto a recording material, a fixing device for fixing the transferred transparent toner image on the recording material, and a controller for controlling the bearing amount of the transparent toner image formed on the image bearing member, and the controller controls a condition for forming the transparent toner image to change the bearing amount of the transparent toner image in accordance with the fixing temperature of the fixing device.

A developing apparatus having: a first developer carrying member close to a developer regulating member for regulating an amount of developer; a second developer carrying member to which the developer is delivered from the first developer carrying member; and a mode for removing the toner on the surface of the second developer carrying member, in which mode, in a non-image-formation period, no toner transfer operation from the first developer carrying member to an image bearing member is substantially performed, but a toner transfer operation from the second developer carrying member to the image bearing member is performed.

An image forming apparatus includes a toner image forming device for forming a toner image on a recording material with transparent or white toner. A fixing device fixes the toner image on the recording material. A fixed toner image detection device detects the toner image fixed on the recording material. A controller variably controls a toner image forming condition of the toner image forming device on the basis of a detection result of the fixed toner image detection device, which detects a glossiness of the toner image. The toner image forming condition, which is variably controlled by the controller, is a weight of the toner per unit area of the toner image on the recording material.

In a device for controlling the amount of toner replenished to a developing device depending on the density of a reference image formed on a photoconductor, if the toner density of a developer in the developing device fluctuates extremely; there may occur toner scattering, formation of coarse or rough images, and carrier attachment. To overcome those problems, a photosensor is disposed to detect the toner density in the developing device, and when an output of the photosensor is outside of a predetermined range, a target value to be compared with the detected density of the reference image is modified.

An image forming apparatus capable of preventing the increase of the size thereof by having a lengthened developer bearing member is provided with regard to an image forming apparatus capable of printing a registration mark (dragonfly) on a large sheet of recording paper for producing an art work in case of the use of a formed image as a printing manuscript. The length of the lengthwise direction of a developer bearing member provided in at least one developing device among the developing devices provided in the image forming apparatus is longer than those of the developer bearing members of the other developing devices.

An image forming apparatus includes a toner image forming portion for forming a toner image on a first image bearing member, a first transferring portion for transferring, onto a second image bearing member, the toner image on the first image bearing member, a second transferring portion for transferring, onto a transferring material, the toner image on the second image bearing member, a cleaning unit including a cleaning member abutting on the surface of the second image bearing member, and a transferring material recognizing portion for recognizing a type of the transferring material. The toner image forming portion forms a toner image for cleaning on the first image bearing member in accordance with information about a type of the transferring material that is recognized by the transferring material recognizing portion. The first transferring portion transfers, onto the second image bearing member, the toner image for cleaning on the first image bearing member, and the cleaning unit collects the toner image for cleaning on the second image bearing member.

Image forming apparatus with type-of-transfer material cleaning feature

An image forming apparatus including, an image bearing member, an image forming device for forming a toner image on the image bearing member, a transfer device for electrostatically transferring the toner image formed by the image forming device on the image bearing member to a transfer material, an detector for detecting temperature and humidity in a main body of the apparatus and a controller for such control that the toner amount per unit area of the toner image formed on the image bearing member by the image forming device differs in accordance with a result detected by the detector.

Image forming apparatus that forms a toner image

A transfer apparatus comprising a belt member, a plurality of belt supporting members which drive the belt member while stretching the belt member with a prescribed tension; a transfer member, which is one of the plurality of belt supporting members, and transfers an image formed on an image carrier toward the belt member; and transfer member moving means making it possible only for the transfer member movable between a transfer position where the image is transferred and a non-transfer position where the image is not transferred while maintaining the prescribed tension.

Transfer apparatus and image forming apparatus

An image forming apparatus includes an image bearing member, an image forming portion for forming an image on the image bearing member, a contact transferring member for transferring the image formed on the image bearing member onto a transferring medium, a transferring current applying portion for applying a current to the contact transferring member, and a controller for controlling an amount of the current applied by the transferring current applying portion. Images formed on the image bearing member are transferred in a superposed manner onto the transferring medium, which is being conveyed. The controller determines an amount of current to be applied to the contact transferring member based on: the image ratio in the direction perpendicular to the direction in which the transferring medium is conveyed, of an image that has already been transferred on the transferring medium; the image ratio in the direction perpendicular to the direction in which the transferring medium is conveyed, of an image on the image bearing member; and the image ratio in the direction perpendicular to the direction in which the transferring medium is conveyed, of a portion in which the images overlap.

Image forming apparatus including contact transfer member having transfer current controlled in accordance with ratio of image portion at transfer portion

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Abiko, Japan

Yuji Bessho