Canon Kabushiki Kaisha

Kohei Okayasu

Satoshi Nishida

Masashi Tanaka

Takaaki Akamatsu

Shinsuke Kobayashi

Kenji Shindo

Takao Kume

Takanori Mitani

Hiroki Sasame

Shingo Ito

Takehiko Suzuki

Isamu Takeda

Keisuke Fujita

Shogo Kan

Takanori Watanabe

Shuichi Tetsuno

Kenichi Iida

Hideo Nanataki

Kenichi Ogawa

Akimichi Suzuki

Masafumi Maeda

Takeshi Shinji

Sho Taguchi

Hironori Kato

Takuya Hayato

An image forming apparatus includes a plurality of developing member to form toner images, respectively, a transfer member to sequentially transfer the toner images onto a recording material and to overlappingly form toner on the recording material. A fixing member presses and heats the recording material on which the toner images are transferred and fixes the toner images on the recording material. A storage medium stores a usage history of the developing member. A controller controls a fixing temperature of the fixing member. The controller determines the fixing temperature based on a difference between the usage history of one of the developing member stored in the storage medium and the usage history of another of the developing member.

Image forming apparatus

An image forming apparatus includes: a first and second rotation bodies; a heater disposed in the first rotation body; and a frame body supporting the first and second rotation bodies. A second length is smaller than a first length in a rotational axis direction of the second rotation body, the first length and the second length being a length of a rotation shaft of the second rotation body exposed on a one-end side and an other-end side of the second rotation body, and a second value is larger than a first value, the first value and the second value being a total area of openings disposed in a first region and a second region of the frame body respectively corresponding to the one-end side and the other-end side of the frame body with respect to a center of the frame body.

An image forming apparatus includes an image forming unit including an image bearing member, an intermediate transfer member, and a transfer roller, a conveyance rotary member pair, a fixing unit, a first conveyance path, a second conveyance path, a reverse conveyance unit, and a control unit. The control unit is configured to perform a conveyance operation of conveying the sheet, the conveyance operation including (i) a first conveyance processing of conveying the sheet toward the reverse conveyance, (ii) a second conveyance processing of conveying the sheet toward the second conveyance path by the reverse conveyance unit, and (iii) a third conveyance processing of transferring the toner image to the sheet at the transfer nip portion. A surface, of the sheet, that faces the pressure roller in the first conveyance processing is configured to face the intermediate transfer member in the third conveyance processing.

A fixing apparatus includes first and second rotating members, a heater having a heating element and a substrate, and first and second contact members. A direction of a longer side on a surface of the substrate where the heating element is disposed is a longitudinal direction. A direction intersecting the longitudinal direction is a widthwise direction. The first contact member is disposed in a region outside a region where a maximum size recording material conveyed to a nip portion passes through the nip portion on one end side in the longitudinal direction on an outer circumferential surface of the first rotating member, and the second contact member is disposed in the region outside the region where the maximum size recording material conveyed to the nip portion passes through the nip portion on an other end side in the longitudinal direction on an outer circumferential surface of the second rotating member.

Fixing apparatus and image forming apparatus

An image-forming apparatus includes first and second photosensitive drums, first and second image-forming portion including first and second development rollers configured to bear developers composed of first and second toner particles and organosilicon protrusions formed on surfaces of the first and second toner particles, an intermediate transfer member to which a developer image is to be transferred in first and second contact portions in contact with the first and second photosensitive drums, and a transfer member configured to transfer the developer image to a recording material in a transfer portion. The first contact portion is formed downstream of the transfer portion and upstream of the second contact portion in a movement direction of the surface of the intermediate transfer member. A protrusion formed on the second developer has a lower height than a protrusion formed on the first developer.

Image-forming apparatus

A region of an image bearing member that comes into contact with a recording material at a nip in a state in which the recording material is held by the nip is a first region, and a region of the image bearing member that does not come into contact with the recording material at the nip in a state in which the recording material is not held by the nip is a second region. A controller controls to apply a first developing voltage to a developer bearing member when the first region in which a first surface potential has been formed faces a developer bearing member and apply a second developing voltage lower than an absolute value of the first developing voltage to the developer bearing member when the second region in which a second surface potential has been formed faces the developer bearing member.

Image forming apparatus that controls voltages to reduce image fogging

An image forming apparatus including: an obtaining portion that divides image data into a plurality of regions in a sub scanning direction, and obtains, for each of the plurality of regions in the sub scanning direction, a first value relating to pixels having density at at least a prescribed value in a first width and a second value relating to pixels having density at at least the prescribed value in a second width, which is greater than the first width; a determining portion that determines, for each of the plurality of regions, a target temperature for maintaining a temperature of a heating member on the basis of the first and second values; and a control portion that controls power supplied to the heating member so that the temperature of the heating member is maintained at the target temperature.

Image forming apparatus, image forming method, and computer-readable recording medium with program recorded therein

An image forming apparatus includes a photoconductor including a charge generation layer; a charging member to charge a surface of the photoconductor; and an exposure unit to expose the surface of the photoconductor to form a toner image on the surface of the photoconductor charged. The exposure unit exposes the surface of the photoconductor by scanning a laser beam in a main scanning direction at a non-constant scan rate, and exposure amount per unit length of the surface of the photoconductor in the main scanning direction is larger in a first region than in a second region. The first region is in the surface of the photoconductor exposed at a first scan rate. The second region is in the surface of the photoconductor exposed at a second scan rate higher than the first scan rate. The charge generation layer is thinner in the first region than in the second region.

Image forming apparatus for controlling an exposure amount on a surface of a photoconductor

An image forming apparatus includes an image forming unit configured to form an image based on image data, a fixing unit configured to fix the image formed by the image forming unit on a recording material, a conversion unit configured to convert image data into conversion data including a plurality of areas having a first resolution in a main scanning direction perpendicular to a conveyance direction of the recording material, and a second resolution higher than the first resolution in a sub-scanning direction, which is the conveyance direction of the recording material, an analysis unit configured to analyze values related to the areas of the plurality of areas of the conversion data obtained by the conversion unit, and a temperature control unit configured to control a fixing temperature of the fixing unit according to a result of the analysis performed by the analysis unit.

Image forming apparatus, image forming system, and image forming method each controlling fixing temperature

There is provided an image forming apparatus including a configuration in which a voltage of a polarity opposite to a toner charging polarity is applied. In the image forming apparatus, a guide region of a pre-transfer guide is located on a photosensitive drum side with respect to a common tangent line of a photosensitive drum and a development roller to reduce contamination of the pre-transfer guide and prevent contamination of recording materials.

Guide member and image forming apparatus comprising the same

An image forming apparatus includes a discharging device for discharging the drum at a discharging portion opposing the surface of the drum; and a control unit for executing, during non-image formation, a cleaning operation for transferring the toner deposited on the transfer member onto the drum by applying a voltage from transfer voltage source to the transfer member. The control unit does not effect discharge by the discharging device for at least a region of the drum where a transfer voltage for transferring a normal-polarity toner of the toner deposited on the transfer member onto the drum is applied to the transfer member in the cleaning operation, and then passes the region of the drum through the charging portion in a state in which a voltage larger than a surface potential of the drum in a normal polarity side is applied to the charging member.

Image forming apparatus including cleaning operation

In a configuration in which a voltage of polarity opposite to charging polarity of toner is applied to a conveyance guide, controlling deposition of toner on the conveyance guide has been difficult. When performing duplex image formation, a potential difference between a surface potential of a photoconductive drum charged by a charging roller and a potential of the conveyance guide is smaller during printing on the second surface than during printing on the first surface.

Image forming apparatus for duplex operation using potential differences

An image forming apparatus includes a developing unit which develops a toner image on a surface of a photosensitive member and which collects toner which remains on the surface of the photosensitive member after the developed toner image is transferred to a transfer member. The image forming apparatus includes a controller configured to determine whether a cleaning operation of cleaning the surface of the photosensitive member is to be performed after an image forming operation is performed or control a period of time in which the cleaning operation is performed in accordance with a measured downtime of the image forming apparatus which is a period of time after the image forming operation is terminated and before a next image forming operation is started.

Growing community of inventors

Mishima, Japan

Kohei Okayasu