Canon Kabushiki Kaisha

Tomoo Akizuki

Yusuke Shimizu

Masahiko Suzumi

Ryo Morihara

Seiji Saito

Keisuke Ishizumi

Tatsuya Kinukawa

Ken Nakagawa

Takeshi Shinji

Takeharu Nakada

Atsutoshi Ando

Toshikazu Tsuchiya

Masao Umezawa

Hiroki Sasame

Toru Saito

Masahiro Suzuki

Masaru Shimura

Kenichi Iida

Takashi Shimada

Michio Uchida

Hikaru Osada

Kenji Kanari

Kazuhiro Doda

Kensuke Umeda

Jun Hara

Shoichiro Ikegami

Naoki Fukushima

Yusuke Nakazono

Yutaka Sato

Satoshi Nishida

Takehiko Suzuki

Motoki Adachi

Keisuke Mochizuki

Masafumi Maeda

Takayuki Kanazawa

Masahide Hirai

Shuhei Kawasaki

Shunsuke Mizukoshi

Osamu Sasaoka

Sho Taguchi

Jun Matsumoto

Akihito Kanamori

Naofumi Murata

Ryosuke Kanai

Shinji Kubo

Tohru Saito

Yusuke Sakamoto

Naoki Fuei

Takuro Mita

Takahiro Endo

Hisahiro Saito

Yuki Oshima

Norihiro Shirahata

Junichi Kubota

Takateru Okubo

Yuusuke Shimizu

Shinobu Akama

An image forming apparatus includes an image bearing member, a charging member, a charging voltage applying portion, an exposure unit, a developing member, a developing voltage applying portion, a cleaning member, and a controller. During a non-image forming operation from a start of rotation of the image bearing member to a start of an image forming operation or from an end of the image forming operation to a stop of the rotation of the image bearing member, in a contact rotation state of the developing member with the image bearing member, the controller effects control so as to execute a supplying operation in which Vback lower or higher than Vback during an image forming operation is generated in a time corresponding to one full rotation of the developing member and toner moved from the developing member to the surface of the image bearing member is supplied to the cleaning portion.

Image forming apparatus

In an image forming apparatus, rotation of an image bearing member is started and stopped in a contact state between the image bearing member and a developing member. During a post-rotation operation, a controller ends application of a charging voltage after changing the charging voltage stepwisely to first and second charging voltages. The controller ends application of a developing voltage after changing the developing voltage stepwisely at a developing position to first and second developing voltages in synchronism with the first and second charging voltages. A potential difference between each of surface potentials of first and second regions and an associated one of the first and second developing voltages is maintained within a predetermined range. The controller carries out control so that an absolute value of the surface potential of at least one of the first and second regions is made low by passing a current under application of a transfer voltage.

Image forming apparatus with control of plural power sources

A charging device has: a charging member that charges an image bearing member; and a cleaning member that is pressed against the charging member, and that is rubbed against a surface of the charging member by rotating the charging member. The cleaning member includes at least a first layer that contains roughening particles and that comes into contact with the charging member. The Martens hardness of the first layer is higher than that of the surface of the charging member. The roughening particles have a Mohs hardness similar to or higher than that of a component of highest Mohs hardness in toner adhered to the surface of the charging member.

Charging device, process cartridge, and image forming apparatus

An image forming apparatus includes a photosensitive member, a charging member, an exposing unit to expose a surface of the photosensitive member, and a developing member to supply toner with normal polarity at a developing portion. A controller, during a non-image formation when a toner image is not formed on a surface of the photosensitive member, controls such that a developing voltage is changed in a predetermined voltage width by applying a first developing voltage while the area of the photosensitive member on which a first surface potential is formed passes through the developing portion and by applying a second developing potential of an opposite polarity side rather than the first developing voltage while the area of the photosensitive member on which a second surface potential is formed passes through the developing portion, and the controller controls such that the surface potential becomes a side of the normal polarity rather than the first developing voltage.

A heater includes: a substrate; an insulating layer that is provided on the substrate; and a heat generating element that is provided on the insulating layer, and in a case where a region including a center of the substrate is defined as a first region, a region on a side closer to one end portion than the first region is defined as a second region, and a region on a side closer to the other end portion than the first region is defined as a third region in a transverse direction that is orthogonal to a longitudinal direction of a surface of the substrate on which the insulating layer is provided, the first region is a plane, and the second region and the third region are bent from the first region in a thickness direction of the substrate that is orthogonal to the longitudinal direction and the transverse direction.

Heater, heating device, and image forming apparatus

An image forming apparatus includes a developer bearing member, a supply member, first and second voltage application units, and a control unit. Assuming that a difference between a voltage to be applied to the developer bearing member by the first voltage application unit and a voltage to be applied to the supply member by the second voltage application unit in the image forming operation is defined as a first supply contrast, and a difference between the voltage to be applied to the developer bearing member by the first voltage application unit and the voltage to be applied to the supply member by the second voltage application unit in the preliminary rotation operation is defined as a second supply contrast, the control unit controls the second supply contrast to be less than the first supply contrast or to have polarity reversed from polarity of the first supply contrast.

An image forming apparatus includes a photosensitive member, a developing member to supply a toner to the photosensitive member at a developing portion, and a transfer member to transfer a toner image to a recording material passing through a transfer portion from the photosensitive member. In a case which the transfer is performed to a shorter width recording material and thereafter, the transfer is successively performed to a longer width recording material, a control portion controls a first back contrast formed when an area of a surface of the photosensitive member corresponding to the transfer portion through which the shorter width recording material is passing reaches the developing portion, and a second back contrast formed when an area of the surface corresponding to the transfer portion through which the longer width recording material is passing reaches the developing portion so that the second back contrast is higher than the first back contrast.

An image forming apparatus includes an image forming unit, a fixing unit, an image analyzer, and a temperature controller configured to control a temperature of the fixing unit in accordance to a target temperature. The image analyzer is configured to analyze image data for forming the toner image by the image forming unit, to evaluate a continuity of pixels of an image contained in the image data. The temperature controller is configured to change the target temperature based on analysis results of the image analyzer such that a value of the target temperature in a case where the image data contains an image with a continuity of pixels equal to or smaller than a predetermined value is higher than a value of the target temperature in a case where the image data contains no image with a continuity of pixels equal to or smaller than the predetermined value.

Image forming apparatus that sets a target temperature for a fixing unit based on a minimum number of continuous pixels in a line

A heater includes a substrate formed of metal into a plate shape in which a length in a longitudinal direction thereof is greater than a length in a short direction thereof when viewed in a thickness direction thereof, an insulating layer formed of insulating material on a first surface of the substrate on a first side in the thickness direction, a heating element arranged on the insulating layer and configured to generate heat by flowing electric current therethrough, and a cover layer arranged to cover the heating element. The heater is a warped shape when receiving no external force, such that a center portion of the heater in the longitudinal direction protrudes to the first side in the thickness direction compared to both end portions of the heater in the longitudinal direction.

Heater, fixing unit and image forming apparatus

In an image forming apparatus, in a case in which a second toner image to be transferred to a same recording material as a first toner image is to be transferred is formed on the photosensitive member after the first toner image is formed on the photosensitive member and the first toner image is formed on an area of the photosensitive member including at least a part of a position of the second toner image one cycle before with respect to a movement direction of the surface of the photosensitive member, a control unit changes a value of a transfer current at a time of transferring the first toner image to a transfer-receiving member between a first value and a second value of which an absolute value is greater than an absolute value of the first value, based on image information regarding the second toner image.

Image forming apparatus that controls transfer current in a case in which a second toner image is transferred to a same recording material as a first toner image

A fixing apparatus includes a tubular film, an elongate plate-like heater including a first surface in contact with an inner surface of the film and a second surface opposite to the first surface, the heater being in contact with the inner surface of the film with the second surface, a heat conducting member that is long along the length of the heater and is in contact with the second surface of the heater, and a support member capable of rotating the film while supporting the heater, with the heat conducting member therebetween. The heat conducting member includes an extending portion extending, outside an upstream end of the heater in a rotational direction of the film, in a direction from the second surface of the heater toward the first surface. The extending portion includes a contact portion protruding from the first surface of the heater toward the film into contact therewith.

Fixing apparatus including a heat conducting member with an extending portion extending upstream of the heater

An image forming apparatus includes a photosensitive member; a scan unit configured to scan the photosensitive member with light based on image data, and form a latent image on the photosensitive member; a developing unit configured to form an image on the photosensitive member by attaching toner to the latent image formed on the photosensitive member; and a correction unit configured to correct an exposure amount of the photosensitive member such that a density change of the image in a main scanning direction due to a configuration of the scan unit and a density of the image to be formed is reduced.

Image forming apparatus correcting exposure amount of photosensitive member

In a first operation mode in which a first addition value for each sheet of a recording material and a first initial control temperature, when the total sum of the first addition values exceeds a predetermined threshold value, a control portion of an image heating portion, which heats an image on the recording material, of an image forming apparatus changes the first initial control temperature to a first correction control temperature. When the operation mode is changed from the first operation mode to a second operation mode in which a second addition value different from the first addition value and a second initial control temperature different from the first initial control temperature, the control portion corrects the first correction control temperature based on a difference between initial control target temperatures.

Image forming apparatus that changes a control target temperature in accordance with a number of sheets of recording material that have passed through an image heating portion

A fixing apparatus includes a holding member including a groove-like holding portion, a heater supported by the holding portion, a film rotatable around the heater, the film being configured to be heated by sliding on the heater and to heat a toner image on a printing material, and a gap filling member including, on an upstream side with respect to the heater in a direction in which the circumferential surface of the film moves, a first portion disposed between the heater and the holding member and a first contact portion connecting to the first portion and being in contact with the film. A second distance between the first portion and the holding member disposed upstream from the first portion and facing the first portion is smaller than a first distance between the heater and the first portion disposed upstream from the heater and facing the holding member.

Fixing apparatus

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Kawasaki, Japan

Tomoo Akizuki