Abstract: 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.

Abstract: 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.

Abstract: An image forming apparatus includes a rotatable image bearing member, a charging member, a rotatable developer carrying member, a developing voltage applying portion, a detecting portion for detecting a first current value and a second current value of currents flowing between the image bearing member and the developer carrying member, and a controller for controlling the applying portion. When a difference between the first current value and the second current value which are detected by the detecting portion exceeds a threshold in a state in which the image bearing member and the developer carrying member are rotated and the developing voltage is applied to the developer carrying member, the controller controls the AC voltage of the developing voltage applied to the developer carrying member.

Abstract: 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.

Abstract: 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.

Abstract: 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?r during image formation and a direction of a vector R?r during non-image formation be opposite to each other.

Abstract: 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?r during image formation and a direction of a vector R?r during non-image formation be opposite to each other.

Abstract: 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.

Abstract: A developer container includes: a housing chamber 147 which includes an opening 145 and which houses developer; a stirring member 160 which includes a sheet-like stirring portion 160b and a rotary shaft 160a to which the stirring portion 160b is attached; and a first electrode 143 and a second electrode 144 which are used to detect an amount of the developer and which are arranged with an interval therebetween, wherein an area X1 between the first electrode 143 and the second electrode 144 in the housing chamber 147 is positioned below the rotary shaft 160a of the stirring member 160, and the sheet-like stirring portion 160b comes into contact with the area X1 due to rotation of the stirring member 160.

Abstract: 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.

Abstract: A developer container includes: a housing chamber 147 which includes an opening 145 and which houses developer; a stirring member 160 which includes a sheet-like stirring portion 160b and a rotary shaft 160a to which the stirring portion 160b is attached; and a first electrode 143 and a second electrode 144 which are used to detect an amount of the developer and which are arranged with an interval therebetween, wherein an area X1 between the first electrode 143 and the second electrode 144 in the housing chamber 147 is positioned below the rotary shaft 160a of the stirring member 160, and the sheet-like stirring portion 160b comes into contact with the area X1 due to rotation of the stirring member 160.

Abstract: A developer container includes: a housing chamber 147 which includes an opening 145 and which houses developer; a stirring member 160 which includes a sheet-like stirring portion 160b and a rotary shaft 160a to which the stirring portion 160b is attached; and a first electrode 143 and a second electrode 144 which are used to detect an amount of the developer and which are arranged with an interval therebetween, where in an area X1 between the first electrode 143 and the second electrode 144 in the housing chamber 147 is positioned below the rotary shaft 160a of the stirring member 160, and the sheet-like stirring portion 160b comes into contact with the area X1 due to rotation of the stirring member 160.

Abstract: 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 second value than when it is a first value, the second value being smaller than the first value.

Abstract: 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.

Abstract: A developer container includes: a housing chamber 147 which includes an opening 145 and which houses developer; a stirring member 160 which includes a sheet-like stirring portion 160b and a rotary shaft 160a to which the stirring portion 160b is attached; and a first electrode 143 and a second electrode 144 which are used to detect an amount of the developer and which are arranged with an interval therebetween, where in an area X1 between the first electrode 143 and the second electrode 144 in the housing chamber 147 is positioned below the rotary shaft 160a of the stirring member 160, and the sheet-like stirring portion 160b comes into contact with the area X1 due to rotation of the stirring member 160.

Abstract: Provided is an image forming apparatus including voltage applying unit for applying voltages to a developer carrier in which a surface that carries a developer is configured so that a plurality of dielectric portions is interspersed on a surface formed of a conductor portion, and to a regulating member that regulates a layer thickness of the developer that is carried on the developer carrier. The voltage applying unit has a period, during non-image formation, over which voltage such that an absolute value of potential difference between voltage applied to the developer carrier and voltage applied to the regulating member is greater than that during image formation is applied to at least one of the developer carrier and the regulating member.

Abstract: 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.

Abstract: A blade-like charging member for charging a surface of an image bearing member by contacting thereto and by being supplied with a voltage, includes a charging portion for effecting electric discharge to the surface of the image bearing member; a non-charging portion not effecting the electric discharge to the surface of the image bearing member; non-charging portion capable of contacting the image bearing member with maintaining an electrically dischargeable gap between the charging portion and the image bearing member, wherein at least a part of the non-charging portion is made of a material having a higher resistance than that of the charging portion so as to prevent electric discharge between the non-charging portion and the surface of the image bearing member, and the non-charging portion is contacted to and slidable on the surface of the image bearing member over a range not less than a longitudinal dimension of the charge portion, and wherein when the surface of the image bearing member is charged, a cl

Abstract: 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 rot

Abstract: 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 rot