Abstract: A developing apparatus includes a first chamber for accommodating a developer, the first chamber being provided with a developer carrying member for carrying the developer; a second chamber communicated with the first chamber through communication openings provided at opposite end portions to establish a circulation path; a feeding member, provided in the second chamber, for feeding the developer in a feeding direction which is from one of the communication openings toward the other communication opening; a sealing portion for openably sealing the communication openings; a moving mechanism for opening the communication openings by moving the sealing portion; and a reverse feeding member for feeding the developer in a direction which is opposite the feeding direction.

Abstract: An image forming apparatus for forming an image on a recording material. A process cartridge, including a photosensitive drum and a process device actable on the drum, is detachably mountable to a main assembly of the image forming apparatus in a direction of an axis of the drum. The image forming apparatus includes a first positioning portion, provided above the cartridge, for positioning, with respect to a direction crossing with the axis of the drum, the drum at an upstream position with respect to a mounting direction in which the cartridge is mounted to the main assembly of the apparatus, and a second positioning portion, provided above the cartridge at a downstream position with respect to the mounting direction, for positioning the drum with respect to a direction crossing with the axis of the drum.

Abstract: An image forming apparatus forms an image on a recording material, and detachably mounts process cartridges having photosensitive drums. The apparatus includes a main assembly, a rotatable openable member, a belt receiving an image or carrying the recording material, supporting members supporting the process cartridges at different levels and movable between drum-contacting and retracted positions, and a connecting member moving the supporting member when the openable members moves to position the supporting member at the drum-contacting position when the openable member is closed, and position the supporting member at the retracted position when the openable member is opened, and including a shaft whose axis crosses the openable member rotational axis, first connecting portions rotatably connected with respective supporting members, and a second connecting portion engaging the openable member and fixed to the shaft closer to the openable member than the first connecting portions are fixed to the shaft.

Abstract: An image rewriting apparatus for forming an image on a recording material. A process cartridge, including a photosensitive drum and a process device actable on the drum, is detachably mountable to a main assembly of the image forming apparatus in a direction of an axis of the drum. The image forming apparatus includes a first positioning portion, provided above the cartridge, for positioning, with respect to a direction crossing with the axis of the drum, the drum at an upstream position with respect to a mounting direction in which the cartridge is mounted to the main assembly of the apparatus, and a second positioning portion, provided above the cartridge at a downstream position with respect to the mounting direction, for positioning the drum with respect to is direction crossing with the axis of the drum.

Abstract: An image forming apparatus forms an image on a recording material, detachably mounts a process cartridge including a photosensitive drum, and includes first and second positioning portions respectively positioning the drum upstream and downstream with respect to a cartridge mounting direction, a coupling engaging a drum coupling and transmitting a driving force to the drum, and a support supporting the cartridge at a first position positioning the drum to the first and second positioning portions and at a second position spacing the drum away from the first and second positioning portions to permit cartridge mounting and dismounting. The support includes a guide engaging the cartridge, and a third positioning portion limiting cartridge rotation relative to the first and second positioning portions when the coupling transmits a driving force to the drum coupling and for positioning the cartridge lower portion at an upstream position with respect to the mounting direction.

Abstract: A process cartridge is detachably mountable to a main assembly of an image forming apparatus and includes an image bearing member, a developing device having a developer carrier, a transmitter transmitting a driving force received from the main assembly to the developer carrier, a charger movable toward and away from the image bearing member, for charging the image bearing member while contacting the image bearing member, a spacer, detachably mountable relative to the cartridge, for holding the charger at a position away from the image bearing member when the spacer is mounted and for permitting the charger to charge the image bearing member when the spacer is dismounted, and a drive controller for disengaging the driving connection between the transmitter and the developer carrier when the spacer is mounted, and for establishing the driving connection between the transmitter and the developer carrying member when the spacer is dismounted.

Abstract: An image forming apparatus forms an image on a recording material, detachably mounts a process cartridge including a photosensitive drum, and includes first and second positioning portions respectively positioning the drum upstream and downstream with respect to a cartridge mounting direction, a coupling engaging a drum coupling and transmitting a driving force to the drum, and a support supporting the cartridge at a first position positioning the drum to the first and second positioning portions and at a second position spacing the drum away from the first and second positioning portions to permit cartridge mounting and dismounting. The support includes a guide engaging the cartridge, and a third positioning portion limiting cartridge rotation relative to the first and second positioning portions when the coupling transmits a driving force to the drum coupling and for positioning the cartridge lower portion at an upstream position with respect to the mounting direction.

Abstract: An image forming apparatus forms an image on a recording material, and detachably mounts process cartridges having photosensitive drums. The apparatus includes a main assembly, a rotatable openable member, a belt receiving an image or carrying the recording material, supporting members supporting the process cartridges at different levels and movable between drum-contacting and retracted positions, and a connecting member moving the supporting member when the openable members moves to position the supporting member at the drum-contacting position when the openable member is closed, and position the supporting member at the retracted position when the openable member is opened, and including a shaft whose axis crosses the openable member rotational axis, first connecting portions rotatably connected with respective supporting members, and a second connecting portion engaging the openable member and fixed to the shaft closer to the openable member than the first connecting portions are fixed to the shaft.

Abstract: An image forming apparatus forms an image on a recording material, detachably mounts a process cartridge including a photosensitive drum, and includes first and second positioning portions respectively positioning the drum upstream and downstream with respect to a cartridge mounting direction, a coupling engaging a drum coupling and transmitting a driving force to the drum, and a support supporting the cartridge at a first position positioning the drum to the first and second positioning portions and at a second position spacing the drum away from the first and second positioning portions to permit cartridge mounting and dismounting. The support includes a guide engaging the cartridge, and a third positioning portion limiting cartridge rotation relative to the first and second positioning portions when the coupling transmits a driving force to the drum coupling and for positioning the cartridge lower portion at an upstream position with respect to the mounting direction.

Abstract: An image forming apparatus forms an image on a recording material, and detachably mounts which process cartridges having photosensitive drums. The apparatus includes a main assembly, a rotatable openable member, a belt receiving an image or carrying the recording material, supporting members supporting the process cartridges at different levels and movable between drum-contacting and retracted positions, and a connecting member moving the supporting member when the openable member moves to position the supporting member at the drum-contacting position when the openable member is closed, and position the supporting member at the retracted position when the openable member is opened, and including a shaft whose axis crosses the openable member rotational axis, first connecting portions rotatably connected with respective supporting members, and a second connecting portion engaging the openable member and fixed to the shaft closer to the openable member than the first connecting portions are fixed to the shaft.

Abstract: An image forming apparatus detachably mounts a cartridge and forms an image on a recording material. The apparatus includes a cartridge positioning portion, a movable member movable between a first position for positioning the cartridge to the positioning portion when the cartridge is mounted to a main assembly of the apparatus, and a retracted position, for permitting cartridge main-assembly mounting in a cartridge longitudinal direction. The movable member has an urging member urging the cartridge to the positioning portion when the movable member takes the first position. Also provided is a guiding member movable relative to the movable member to take a guide position guiding the cartridge when the movable member takes the retracted position and a position retracted from the guide position away from the cartridge when the movable member takes the first position.

Abstract: A developing apparatus includes a first chamber for accommodating a developer, the first chamber being provided with a developer carrying member for carrying the developer; a second chamber communicated with the first chamber through communication openings provided at opposite end portions to establish a circulation path; a feeding member, provided in the second chamber, for feeding the developer in a feeding direction which is from one of the communication openings toward the other communication opening; a sealing portion for openably sealing the communication openings; a moving mechanism for opening the communication openings by moving the sealing portion; and a reverse feeding member for feeding the developer in a direction which is opposite the feeding direction.

Abstract: An image forming apparatus includes a photosensitive member; a developing device for developing an electrostatic image formed on said photosensitive member into a toner image; a transfer charger for transferring a toner image from said photosensitive member onto an image receiving member; a non-rotational brush and a rotatable brush for electrically charging toner, which remains on said photosensitive member after image transfer by said transfer charger, to collect the remaining toner into said developing device; a driving mechanism provided with a driving source for rotating said rotatable brush; and a moving mechanism for reciprocating said non-rotational brush by a driving force through said rotatable brush in a direction along an axis of said photosensitive member.

Abstract: A process cartridge is detachably mountable to a main assembly of an image forming apparatus and includes an image bearing member, a developing device having a developer carrier, a transmitter transmitting a driving force received from the main assembly to the developer carrier, a charger movable toward and away from the image bearing member, for charging the image bearing member while contacting the image bearing member, a spacer, detachably mountable relative to the cartridge, for holding the charger at a position away from the image bearing member when the spacer is mounted and for permitting the charger to charge the image bearing member when the spacer is dismounted, and a drive controller for disengaging the driving connection between the transmitter and the developer carrier when the spacer is mounted, and for establishing the driving connection between the transmitter and the developer carrying member when the spacer is dismounted.

Abstract: An image forming apparatus includes a photosensitive member; a developing device for developing an electrostatic image formed on said photosensitive member into a toner image; a transfer charger for transferring a toner image from said photosensitive member onto an image receiving member; a non-rotational brush and a rotatable brush for electrically charging toner, which remains on said photosensitive member after image transfer by said transfer charger, to collect the remaining toner into said developing device; a driving mechanism provided with a driving source for rotating said rotatable brush; and a moving mechanism for reciprocating said non-rotational brush by a driving force through said rotatable brush in a direction along an axis of said photosensitive member.

Abstract: An image forming apparatus forms an image on a recording material, detachably mounts a process cartridge including a photosensitive drum, and includes first and second positioning portions respectively positioning the drum upstream and downstream with respect to a cartridge mounting direction, a coupling engaging a drum coupling and transmitting a driving force to the drum, and a support supporting the cartridge at a first position for positioning the drum to the first and second positioning portions and at a second position spacing the drum away from the first and second positioning portions to permit cartridge mounting and dismounting. The support includes a guide engaging the cartridge, and a third positioning portion limiting cartridge rotation relative to the first and second positioning portions when the coupling transmits a driving force to the drum coupling and for positioning the cartridge lower portion at an upstream position with respect to the mounting direction.

Abstract: An image forming apparatus detachably mounts a cartridge and forms an image on a recording material. The apparatus includes a cartridge positioning portion, a movable member movable between a first position for positioning the cartridge to the positioning portion when the cartridge is mounted to a main assembly of the apparatus, and a retracted position, for permitting cartridge main-assembly mounting in a cartridge longitudinal direction. The movable member has an urging member urging the cartridge to the positioning portion when the movable member takes the first position. Also provided is a guiding member movable relative to the movable member to take a guide position guiding the cartridge when the movable member takes the retracted position and a position retracted from the guide position away from the cartridge when the movable member takes the first position.

Abstract: An image forming apparatus forms an image on a recording material, and detachably mounts which process cartridges having photosensitive drums. The apparatus includes a main assembly, a rotatable openable member, a belt receiving an image or carrying the recording material, supporting members supporting the process cartridges at different levels and movable between drum-contacting and retracted positions, and a connecting member moving the supporting member when the openable member moves to position the supporting member at the drum-contacting position when the openable member is closed, and position the supporting member at the retracted position when the openable member is opened, and including a shaft whose axis crosses the openable member rotational axis, first connecting portions rotatably connected with respective supporting members, and a second connecting portion engaging the openable member and fixed to the shaft closer to the openable member than the first connecting portions are fixed to the shaft.

Abstract: A discharge device has a discharge wire for discharge in response to a voltage, a supporting block for supporting the discharge wire, an electric contact receiving an AC voltage, and a resistor element placed between the discharge wire and the electric contact. The discharge device serves particularly as a separation charger of an image forming apparatus.

Abstract: A cartridge which is detachably mountable on an image forming apparatus is provided with non-volatile storing medium. In this non-volatile storing medium, a predetermined value is stored. The predetermined value is used for controlling the image forming apparatus together with the count value which is counted when forming images. The count value for counting images formed in a first image formation mode is different from the count value that is counted when forming images in a second image formation mode whose maximum amount of waste toner contained in a cleaning container is different from that of the first image mode. With the structure thus arranged, the number of printable sheets is made greater before the waste toner is filled in the cleaning container up to its limit, hence enabling the user to secure a longer period of time for preparing the cartridge.