Abstract: A process cartridge is detachably mountable to a main assembly of an electrophotographic image forming apparatus. The cartridge includes a drum, first and second guidable portions guidable by first and second guides when the cartridge enters or advances in the main assembly, first and second regulatable portions provided at leading and trailing sides of the cartridge with respect to the advancing direction and regulated by a first main assembly regulator when the process is advancing in the main assembly, first and second positionable portions to be positioned at first and main assembly second positioners, respectively, by the urging force of a main assembly urging member after the first and second regulatable portions pass the first and second regulators, respectively. The cartridge is mounted to the main assembly with the first and second positionable portions at the first and second positioners, respectively, by the urging force of the urging member.

Abstract: A process cartridge is detachably mountable to a main assembly of an electrophotographic image forming apparatus. The cartridge includes an electrophotographic photosensitive drum, a drum unit supporting the drum, a developing unit supporting a developing roller and swingably coupled with the drum unit, drum and developing roller rotating force receiving portions, first and second positionable portions positioned at first and second main assembly side positioning portions by contacting by an urging force of first and second main assembly side urging members, a developing device spacing force receiving portion, first and second cartridge side rotation regulating portions for limiting rotation of the drum unit by abutting first and second main assembly side rotation regulating portions when the drum and developing roller rotating force receiving portions receive the rotating forces or when the developing device spacing force receiving portion receives the urging force from the main assembly.

Abstract: A developing device frame unit supporting a regulating member regulating the layer thickness of developer on a developer carrier. The unit includes a frame having a seal forming portion, first and second end seals contactable to the carrier surface to prevent carrier-axial-direction leaking of the developer, and a blade sealer sealing between the regulating member and the frame to prevent developer leaking when the regulating member is mounted. The blade sealer is an elastomer resin material which is injection-molded with a metal mold and in the seal forming portion where the end seals are provided. The blade sealer connects the end seals with each other, and a protrusion provided by a squeezed-out portion of the resin material is provided by injecting, into a space defined by the metal mold, the seal forming portion, and the end seals, a resin material volume larger than a volume of the space.

Abstract: A generally circular compression piston ring having an outer peripheral surface, an inner peripheral surface, and a pair of end faces splitting the circular shape in a radial direction thereof for defining a gap portion. The ring has a first portion including a notched portion formed at the inner peripheral surface and extending over a predetermined circumferential length portion starting from the end face, and a second portion other than the first portion. The second portion has a radial thickness ranging from 2.0 mm to 6.0 mm. The notched portion is a plane shape gradually reaching the outer peripheral surface toward the end face. The end face has a radial thickness ranging from 0.2 times to less than 0.5 times as large as the radial thickness of the second portion. The outer peripheral surface defines a center serving as a center of a center angle, and the predetermined circumferential length portion is defined by the center angle ranging from 26.5 degrees to 14 degrees.

Abstract: A cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus. The apparatus includes movable first and second engageable members. The cartridge includes an electrophotographic photosensitive drum, a developing roller, a first force receiving portion for receiving, from the first engageable member, a force for separating the drum and roller, a second force receiving portion for keeping the drum and roller spaced from each other and for receiving a force, from the second engageable member, for separating the first engageable member and the first force receiving portion. When the cartridge is transported while being in a mounted state, the second force receiving portion receives a force for separating the first engageable member and the first force receiving portion from each other from the second engageable member.

Abstract: A process cartridge including: a photosensitive drum; a photosensitive unit rotatably supporting the photosensitive drum; and a protecting cover mountable to an electrophotographic image forming apparatus main body, for protecting the photosensitive drum exposed outside of the photosensitive unit, the protecting cover including: a guide portion for guiding the process cartridge to an inside of the apparatus main body along a longitudinal direction of the photosensitive drum; a positioned portion provided at a leading end of the protecting cover so as to be abutted against a positioning portion of the apparatus main body, for positioning the protecting cover in a direction crossing the longitudinal direction; and an engaged portion provided at the leading end so as to be engaged with an engaging portion of the apparatus main body, for regulating coming off of the protecting cover from the apparatus main body to an upstream side in the insertion direction.

Abstract: A process cartridge is detachably mountable to a main assembly of an electrophotographic image forming apparatus including a positioning portion, a rotatable urging member taking an urging position for urging the cartridge to the positioning portion, and retracted and stand-by positions. The cartridge includes an electrophotographic photosensitive drum, a process device actable on the drum, a positionable portion, a displacing portion moving the urging member from the stand-by to the retracted position by contacting a portion-to-be-displaced disposed at a position remoter from the rotation axis of the urging portion than the urging portion when the cartridge advances along an axial direction of the drum in the main assembly, the displacing portion moving the urging member to the retracted position by contacting the urging member when the cartridge advances in the main assembly, and an urgable portion urgable by the urging portion when the cartridge is set in the main assembly.

Abstract: A process cartridge is detachably mountable to a main assembly of an electrophotographic image forming apparatus. The cartridge includes a drum, first and second guidable portions guidable by first and second guides when the cartridge enters or advances in the main assembly, first and second regulatable portions provided at leading and trailing sides of the cartridge with respect to the advancing direction and regulated by a first main assembly regulator when the process is advancing in the main assembly, first and second positionable portions to be positioned at first and main assembly second positioners, respectively, by the urging force of a main assembly urging member after the first and second regulatable portions pass the first and second regulators, respectively. The cartridge is mounted to the main assembly with the first and second positionable portions at the first and second positioners, respectively, by the urging force of the urging member.

Abstract: A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus. The apparatus includes a movable first engageable member and a movable second engageable member. The cartridge includes an electrophotographic photosensitive drum, a developing roller, a first frame supporting the drum, a second frame supporting the roller, a first force receiving portion for receiving, from the first engageable member, a force for separating the drum and roller a second force receiving portion for keeping the drum and roller spaced from each other and for receiving a force, from the second engageable member, for separating the first engageable member and the first force receiving portion. When the cartridge is transported while being in a mounted state, the second force receiving portion receives a force for separating the first engageable member and the first force receiving portion from each other from the second engageable member.

Abstract: A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus including a cam movable between first and second positions. The cartridge includes a photosensitive drum, a developing roller contactable to the drum to develop a latent image on the drum, a first frame supporting the drum, a second frame supporting the roller and connected with the first frame for rotation about a rotational axis so that roller and the drum are contacted to or spaced from each other, a cam engaging portion for receiving from the cam which is located at the first position a force to space the roller and the drum from each other in a state in which upward movement of the first frame is limited when the cartridge is mounted to the main assembly.

Abstract: A process cartridge is detachably mountable to a main assembly of an electrophotographic image forming apparatus that includes a cam movable between first and second positions. The cartridge includes an electrophotographic photosensitive drum, a developing roller developing an electrostatic latent image formed on the drum, a first frame for supporting the drum, a second frame for supporting the roller and connected with the first frame for relative rotation about a shaft disposed downstream of the roller with respect to a cartridge mounting direction, an entering portion at one end of the second frame with respect to a drum longitudinal direction and downstream of the shaft with respect to the mounting direction, permitting at least a part of the cam to enter when the process cartridge is mounted to the apparatus, and a cam engaging portion engaging the cam to receive a force for spacing the drum and the roller from each other.

Abstract: A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, the process cartridge including a cam member movable between a first position and a second position, the cartridge includes a photosensitive drum; a developing roller contactable to the drum at a development position to develop a latent image formed on the drum; a first frame supporting the drum; second frame supporting the developing roller, the second frame being connected with the first frame for rotation about a rotational axis so that developing roller and the drum are contacted to or spaced from each other; a cam engaging portion for receiving from the cam member which is located at the first position a force effective to space the developing roller and the drum from each other in a state in which upward movement of the first frame is limited when the cartridge is mounted to the main assembly, the cam engaging portion being provided on the second frame at a position downstream of the developmen

Abstract: A process cartridge and an electrophotographic image forming apparatus in which both a developing member and a charging member are separable from an electrophotographic photosensitive member by changing the swinging attitudes of a photosensitive member unit and a developing unit, thereby making it possible to obtain, with a simple construction, a stable image free from unevenness or transversal streaks.

Abstract: A cartridge removably mountable to a main assembly of an electrophotographic image forming apparatus includes a developing member, a developer accommodating portion, a locking portion to engage a locking portion of the main assembly of the apparatus to prevent the cartridge from disengaging from the main assembly after mounting of the cartridge, a grip to be gripped by an operator when the cartridge is mounted to the main assembly, and a releasing portion to move the locking portion of the cartridge in interrelation with a movement of the grip which is moved when the operator grips the grip to disengage the cartridge from the main assembly of the apparatus. The locking between the locking portion of the cartridge and the locking portion of the main assembly is released by the movement of the locking portion of the cartridge.

Abstract: A cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, includes a developing member for developing an electrostatic latent image formed on an electrophotografic photosensitive member, a developer accommodating portion for accommododating a developer to be used for developing an electrostatic latent image by the developing member, a cartridge locking portion for locking the cartridge with a main assembly locking portion provided in the main assembly of the apparatus to prevent the cartridge from disengaging from the main assembly of the apparatus when the cartridge is mounted to the main assembly of the apparatus, and a relasing member for releasing the cartridge locking portion to release the cartridge from the main assembly locking portion when the cartridge is to be removed from the main assembly of the apparatus.

Abstract: In order to suppress uneven densities in an image, an image forming apparatus includes an image bearing member; a first developing unit, including a first developer carrying member, for developing a first latent image formed on the image bearing member; a second developing unit, including a second developer carrying member, for developing a second latent image formed on the image bearing member after the first developing unit has developed the first latent image; and a rotary unit, for holding the first and the second developing units and for moving the first and the second developing unit to positions opposite said image bearing member. Upon the reception of an image forming signal at the image forming apparatus, the first and the second developer carrying members are rotated before the first latent image on the image bearing member is developed.

Abstract: The spacing member includes: a spacing portion for spacing an electrophotographic photosensitive drum and a charging roller when the spacing member is attached to the process cartridge; a stopper portion for preventing a shutter member from retracting from a protection position for covering an exposure portion, when the spacing member is attached to the process cartridge; and a protective portion for covering a positioning portion, which positions the process cartridge in an apparatus body when the process cartridge is mounted in the apparatus body, when the spacing member is attached to the process cartridge. Thus, it is possible to reliably keep the spaced state between the photosensitive drum and the charging roller.

Abstract: A process cartridge and an electrophotographic image forming apparatus in which both a developing member and a charging member are separable from an electrophotographic photosensitive member by changing the swinging attitudes of a photosensitive member unit and a developing unit, thereby making it possible to obtain, with a simple construction, a stable image free from unevenness or transversal streaks.

Abstract: A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, the image forming apparatus including a cam member movable between a first position and a second position away from the first position, the process includes an electrophotographic photosensitive drum; a developing roller, contacted to the electrophotographic photosensitive drum, for developing an electrostatic latent image formed on the drum; a first frame for supporting the drum; a second frame for supporting the developing roller, the second frame being connected with the first frame for relative rotation about a shaft which is disposed downstream of the developing roller with respect to a mounting direction in which the process cartridge is mounted to a main assembly of the apparatus; an entering portion, provided at one end portion of the second frame with respect to a longitudinal direction of the drum and disposed downstream of the shaft with respect to the mounting direction, for permitting at