Canon Kabushiki Kaisha

Yosuke Kishi

Naoki Fukushima

Atsushi Toda

Masahito Kato

Masaki Hirose

Ryosuke Kanai

Hirokazu Fujino

Naoya Asanuma

Daisuke Baba

Kazumi Yamauchi

Katsuichi Abe

Kenta Shibukawa

Shunsuke Matsushita

Nobuyoshi Yoshida

Issei Imamura

Minoru Ito

Kazuaki Iwata

Masaru Kobayashi

Junji Seki

Hiroaki Onuma

A developing apparatus includes a developer bearing member; and a regulating member configured to come in contact with the developer bearing member, and regulate the thickness of the layer of the developer. The contact surface of the regulating member with the developer bearing member satisfies 3≤Rz<20 (μm), 30≤Sm≤100 (μm), and Vmp≥0.05 ml/mwhere Rz represents a maximum height roughness, and Sm represents an average interval of unevenness, and Vmp represents a volume in an initial state of a protruding peak part in parameters in a three-dimensional surface roughness defined in ISO 25178.

Developing apparatus having regulating blade with specific surface properties, process cartridge and image forming apparatus

An image forming apparatus detects a first current value and a second current value of currents flowing between an image bearing member and a developer carrying member. When a difference between the detected first current value and the detected second current value exceeds a threshold in a state in which the image bearing member and the developer carrying member are rotated and a first developing voltage is applied to the developer carrying member, a controller controls AC voltage applied to the developer carrying member.

Non-contact developer bias voltage control for image forming apparatus

An image forming apparatus includes an image bearing member, a rotatable developer carrying member, a rotatable toner supplying member, and a toner accommodating unit. A developing unit including the developer carrying member and the toner accommodating unit are capable of being independently exchanged. The image forming apparatus further includes a current detector and a controller configured to execute a process for notifying information on a lifetime of the developing unit, on the basis of a detection result of the current detector at predetermined timing after use of a fresh toner accommodating unit is started.

Image forming apparatus including notifying information on developing unit lifetime

A developing apparatus, includes: a developer bearing member that encloses a magnet roller having a plurality of magnetic poles and is rotatable; a wall that forms a developer storing chamber for storing a magnetic developer therein; a restricting member configured to restrict a layer thickness of the magnetic developer carried by the developer bearing member; and a moving member configured to move the magnetic developer carried by the developer bearing member before the magnetic developer is restricted by the restricting member, the moving member being brought into contact with a surface of the developer bearing member, the moved developer being on the developer veering member after the moving member moved the developer on the developer bearing member, wherein the moving member is disposed at a position opposed to any of the magnetic pole positions of the plurality of magnetic poles.

Developing apparatus, process cartridge, and image forming apparatus

A developing apparatus, includes: a developer bearing member that is rotatable; an moving member configured to move the magnetic developer carried on the developer bearing member before the magnetic developer is restricted by a restricting member, the moving member being rotatable and brought into contact with a surface of the developer bearing member; and a control portion, wherein, at a contact position between the developer bearing member and the moving member, assuming that a moving speed vector of a surface of the developer bearing member is taken as R and a moving speed vector of a surface of the moving member is taken as r, the control portion controls rotational operation of the developer bearing member and the moving member such that a direction of a vector R&#x2212;r during image formation and a direction of a vector R&#x2212;r during non-image formation be opposite to each other.

Developing apparatus for providing developer to an image bearing member and image forming apparatus having the developing apparatus

A developer container includes: a housing chamberwhich includes an openingand which houses developer; a stirring memberwhich includes a sheet-like stirring portionand a rotary shaftto which the stirring portionis attached; and a first electrodeand a second electrodewhich are used to detect an amount of the developer and which are arranged with an interval therebetween, wherein an area Xbetween the first electrodeand the second electrodein the housing chamberis positioned below the rotary shaftof the stirring member, and the sheet-like stirring portioncomes into contact with the area Xdue to rotation of the stirring member

Developer container, developing apparatus, process cartridge, apparatus main body, and image forming apparatus

An image forming apparatus includes a rotatable photosensitive drum including a photosensitive layer; a drum charging member contacted or disposed closely to the drum, to be supplied with a DC voltage; a developing device; a transfer member for transferring a toner image onto a toner image receiving member; a device for applying to the transfer member a transfer bias voltage; a light projecting portion for projecting light to the drum before the charging and after the image transfer; a controller for controlling a quantity of the projected light, on the basis of the transfer bias and a film thickness of the photosensitive layer, wherein under a condition that the transfer bias is the same, the light amount controlled by the controller is smaller when the film thickness is a fourth value than when it is a third value, the fourth value being smaller than the third value.

Image forming apparatus with reduced posttransfer latent image

A developer container includes: a housing chamberwhich includes an openingand which houses developer; a stirring memberwhich includes a sheet-like stirring portionand a rotary shaftto which the stirring portionis attached; and a first electrodeand a second electrodewhich are used to detect an amount of the developer and which are arranged with an interval therebetween, where in an area Xbetween the first electrodeand the second electrodein the housing chamberis positioned below the rotary shaftof the stirring member, and the sheet-like stirring portioncomes into contact with the area Xdue to rotation of the stirring member

An image forming apparatus includes a developing apparatus having a container for storing a developer, a developer carrier in which a surface that carries the developer is configured so that a plurality of dielectric portions is interspersed on a surface formed of a conductor portion, and a regulating member that regulates a layer thickness of the developer that is carried on the developer carrier. In addition, a voltage applying unit applies voltages to the developer carrier and the regulating member. The voltage applying unit has a period, during non-image formation, over which voltages are applied to the developer carrier and the regulating member, with an absolute value of potential difference between the applied voltages being greater than that when a voltage is applied during image formation to at least one of the developer carrier and the regulating member, such that a force generated to attract the developer toward the developer carrier during non-image formation is weaker than that generated during image formation.

Image forming apparatus having voltage application to regulating member and developer carrier

A blade-like charging member comprises a charging portion, a non-charging portion, and an electrode portion. The non-charging portion is capable of contacting the image bearing member while maintaining an electrically dischargeable gap therebetween. To prevent electric discharge between the non-charging portion and the surface of the image bearing member, at least part of the non-charging portion is made of material having a higher resistance than that of the charging portion. The non-charging portion contacts and slides on the surface of the image bearing member over a range that exceeds the length of the charging portion. A shortest distance between the discharge position and an end portion of the electrode portion with respect to a longitudinal direction of the image bearing member is longer than a shortest distance between the discharge position and a central portion of the electrode portion with respect to the longitudinal direction of the image bearing member.

Charging member and image forming apparatus

A process cartridge detachably mountable to a main assembly of an image forming apparatus includes a rotatable image bearing member on which an image is to be formed; a rotatable roller which is rotated and contacted to the image bearing member at least during image forming operation; and a supporting device for rotatably supporting a shaft of the rotatable roller at least during the image forming operation, the supporting device including an urging member for urging the rotatable roller toward the image bearing member, a bearing member having a holding portion for holding the shaft of the rotatable roller in a position where the rotatable roller is contacted to the image bearing member by the urging member, wherein a relative movement between the rotatable roller and the supporting device is possible by an external force between a first position in which the shaft of the rotatable roller is urged by the urging member while being held by the holding portion, and a second position in which the shaft of the rotatable roller is not held by the holding portion and in which a distance between a rotation axis of the image bearing member and an axis of the rotatable roller is longer than that in the first position.

Process cartridge and image forming apparatus

An image forming apparatus includes a standard exposure device () adjusted to emit light of a predetermined light quantity, and a control device configured to determine light quantity of the pre-charge exposure device in an image-forming period based on the first and the second charging current values, wherein first charging current value is detected when an area on a photosensitive member surface is recharged by the contact charging member, in a case where the photosensitive member is exposed by turning on the standard exposure device without turning on a pre-charge exposure device, and second charging current value is detected when an area on the photosensitive member surface is recharged by the contact charging member, in a case where the photosensitive member charged by applying a predetermined voltage by the contact charging member is exposed by turning on the pre-charge exposure device without turning on the standard exposure device.

Image forming apparatus

An inexpensive image forming apparatus, which can suppress a ghost to obtain an image maintaining satisfactory density and gradations for a long time. The apparatus including an electrophotographic photosensitive member, a contact charger in contact with the photosensitive member for charging the photosensitive member, a charging voltage applying device for applying direct current voltage to the contact charger, a charging current detector for detecting electric current flowing through the contact charger, a pre-exposure device for exposing the photosensitive member to light to remove residual charge on the photosensitive member, and a pre-exposure light amount controller for controlling an exposure light amount of the pre-exposure device in image formation based on the results of detection by the charging current detector when the exposure light amount of the pre-exposure device is changed with direct current voltage applied from the charging voltage applying device to the contact charger during non-image formation.

Growing community of inventors

Suntou-gun, Japan

Yosuke Kishi