A universal coupler includes: a driving shaft, a coupler holder, driving coupler, a driving coupling pin, and an elastic member. The driving shaft has a driving shaft a first pin hole. The coupler holder includes a bore, a separation prevention member that partially blocks the bore, and a coupling groove formed in the bore. The driving coupler includes a spherical portion that is located in the bore and in contact with the separation prevention member, a shaft insertion portion formed through the spherical portion, and a second pin hole that penetrates the spherical portion. The driving coupling pin is insertable into the driving pin hole, and has an end insertable into the coupling groove. The elastic member applies elasticity to the coupler holder in a direction that urges the spherical portion of the driving coupler against the separation prevention member.

A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, includes a rotatable photosensitive drum; a rotatable developing roller configured to develop image formed on the drum, the developing roller being capable of contacting to and spacing from the drum; an urging force receiving portion configured to receive, from a main assembly side urging member, an urging force for spacing the developing roller from the drum; a cartridge side drive transmission member capable of the coupling with a main assembly side drive transmission member and configured to receive, from the main assembly side drive transmission member, a rotational force for rotating the developing roller; and a decoupling member capable of urging the cartridge side drive transmission member by the urging force received by the urging force receiving portion to decouple the cartridge side drive transmission member from the main assembly side drive transmission member.

A coupling member drum unit for a cartridge includes a cylindrical photosensitive drum having an axis L1 and a coupling member operatively connected to the photosensitive drum. The coupling member includes a drum flange provided at an end of the photosensitive drum, with a part of the drum flange being positioned inside of the photosensitive drum, and a connecting part operatively connected to the drum flange. The connecting part includes a cap positioned adjacent to the drum flange, an arm portion extending from the cap in a direction of the axis L1, and a projection projecting from the arm portion in a direction perpendicular to the axis L1, with the projection being movable between a first position and a second position, and with an end of the projection being closer to the axis L1 in the first position than in the second position.

A cartridge includes a photosensitive drum and a coupling member operatively connected to the photosensitive drum, with the coupling member including an arm portion and a projection projecting from the arm portion. The arm portion of the coupling member extends from a point that is upstream in the rotational direction of the photosensitive drum towards a point that is downstream in the rotation direction of the photosensitive drum.

A drum unit for a cartridge includes a cylindrical photosensitive drum having an axis L1 and a coupling member operatively connected to the photosensitive drum. The coupling member includes a first member having a cylindrical portion, a part of the first member being positioned inside of the photosensitive drum and a part of the first member being positioned outside of the photosensitive drum. The coupling member also includes a second member operatively connected to first member, the second member including a plurality of arm portions that are movable relative to the first member, with at least a part of each of the arm portions being positioned inside of the photosensitive drum and inside of the first member.

An image forming unit to be attached to an apparatus body of an image forming apparatus includes a first cartridge including a driven portion configured to rotate on a first rotational axis; and a second cartridge configured separable from the first cartridge. The second cartridge includes an input portion configured to receive driving force from the apparatus body; and a drive transmission portion configured to rotate on a second rotational axis and to transmit the driving force to the driven portion.

A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, includes a rotatable photosensitive drum; a rotatable developing roller configured to develop image formed on the drum, the developing roller being capable of contacting to and spacing from the drum; an urging force receiving portion configured to receive, from a main assembly side urging member, an urging force for spacing the developing roller from the drum; a cartridge side drive transmission member capable of the coupling with a main assembly side drive transmission member and configured to receive, from the main assembly side drive transmission member, a rotational force for rotating the developing roller; and a decoupling member capable of urging the cartridge side drive transmission member by the urging force received by the urging force receiving portion to decouple the cartridge side drive transmission member from the main assembly side drive transmission member.

To provide a process cartridge, a drum unit capable of receiving a driving force from the main assembly, and an image forming apparatus including the process cartridge. A cartridge is provided with a movable member having a driving force receiving portion. The movable member moves between an advanced position and a retracted position.

A process cartridge includes a photosensitive drum and a first casing rotatably supporting the photosensitive drum. The process cartridge also includes a developing roller configured to develop an electrostatic latent image formed on the photosensitive drum with toner, a supplying roller configured to supply the developing roller with the toner, and a second casing rotatably supporting the developing roller and the supplying roller and containing the toner. A rotatable coupling is provided with a projection and operatively connected to the supplying roller and the developing roller so that the coupling can transmit a rotational force to the supplying roller and the developing roller, and at least a part of the coupling being movable in a direction perpendicular to a rotational axis of the coupling. Rotatable gears are configured to transmit the rotational force from the coupling to the developing roller, and a spring urges the at least part of the coupling toward the first casing in the direction perpendicular to the rotational axis of the coupling.

A process cartridge includes a frame having a slit and a recess formed therein at a side of the process cartridge. A photosensitive drum is supported by the frame, with the photosensitive drum being rotatable about an axis thereof, the photosensitive drum including a first end and a second end opposite to the first end. A developing roller is also supported by the frame, the developing roller being rotatable about an axis thereof. A coupling is operatively connected to the photosensitive drum, with the coupling being rotatable about an axis thereof. A helical gear is positioned at the side of the process cartridge, with the helical gear being rotatable about an axis thereof. The helical gear has a plurality of teeth, with at least some of the teeth being exposed teeth that are uncovered by the frame and exposed to outside of the process cartridge.